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FORM 6-K
SECURITIES AND EXCHANGE COMMISSION
Washington, D.C. 20549
Report of Foreign Private Issuer Pursuant to Rule 13a-16 or 15d-16 of the
Securities Exchange Act of 1934
For the month of November 2006
Commission File Number: 001-31819
Gold Reserve Inc.
(Exact name of registrant as specified in its charter)
926 W. Sprague Avenue, Suite 200
Spokane, Washington 99201
(Address of principal executive offices)
Indicate by check mark whether the registrant files or will file annual
reports under cover Form 20-F or Form 40-F.
Form 20-F X Form 40-F _____
Indicate by check mark whether the registrant by furnishing the information
contained in this Form is also thereby furnishing the information to the
Commission pursuant to Rule 12g3-2(b) under the Securities Exchange Act of
1934.
Yes No X
If "Yes" is marked, indicate below the file number assigned to the registrant
in connection with Rule 12g3-2(b): 82-____________
Filed with this Form 6-K is the following, which is incorporated herein by
reference:
99.1 NI 43-101 Technical Report, Brisas Project, Venezuela, Feasibility Update
Certain statements included herein, including those that express management's
expectations or estimates of our future performance or concerning the Brisas
Project, constitute "forward-looking statements" within the meaning of the
United States Private Securities Litigation Reform Act of 1995. Forward-
looking statements are necessarily based upon a number of estimates and
assumptions that, while considered reasonable by management at this time, are
inherently subject to significant business, economic and competitive
uncertainties and contingencies. We caution that such forward-looking
statements involve known and unknown risks, uncertainties and other risks that
may cause the actual financial results, performance, or achievements of Gold
Reserve Inc. to be materially different from our estimated future results,
performance, or achievements expressed or implied by those forward-looking
statements. Numerous factors could cause actual results to differ materially
from those in the forward-looking statements, including without limitation,
concentration of operations and assets in Venezuela; corruption and uncertain
legal enforcement; requests for improper payments; regulatory, political and
economic risks associated with Venezuelan operations (including changes in
previously established legal regimes, rules or processes); the ability to
obtain or maintain the necessary permits or additional funding for the
development of the Brisas Project; in the event any key findings or
assumptions previously determined by us or our experts in conjunction with our
2005 bankable feasibility study (as updated or modified from time to time)
significantly differ or change as a result of actual results in our expected
construction and production at the Brisas Project (including capital and
operating cost estimates); risk that actual mineral reserves may vary
considerably from estimates presently made; impact of currency, metal prices
and metal production volatility; fluctuations in energy prices; changes in
proposed development plans (including technology used); our dependence upon
the abilities and continued participation of certain key employees; and risks
normally incident to the operation and development of mining properties. This
list is not exhaustive of the factors that may affect any of the Company's
forward-looking statements. Investors are cautioned not to put undue reliance
on forward-looking statements. All subsequent written and oral forward-
looking statements attributable to the Company or persons acting on its behalf
are expressly qualified in their entirety by this notice. The Company
disclaims any intent or obligation to update publicly these forward-looking
statements, whether as a result of new information, future events or otherwise.
SIGNATURES
Pursuant to the requirements of the Securities Exchange Act of 1934, the
registrant has duly caused this report to be signed on its behalf by the
undersigned, thereunto duly authorized.
Gold Reserve Inc.
(Registrant)
Date: November 29, 2006
By: s/ Robert A. McGuinness
Name: Robert A. McGuinness
Title: Vice President - Finance & CFO
EXHIBIT INDEX
99.1 NI 43-101 Technical Report, Brisas Project, Venezuela, Feasibility Update
pincock 165 South Union Boulevard, Suite 950
allen & Lakewood, Colorado 80228-2226
holt 303-986-6950
Fax 303-987-8907
www.pincock.com
Consultants for Mining and Financial Solutions
NI 43-101 Technical Report,
Brisas Project, Venezuela,
Feasibility Update
Prepared for
Gold Reserve, Inc.
October 30, 2006
34424
Prepared by
Pincock, Allen & Holt
Richard Addison, P.E.
Richard J. Lambert, P.E.
Susan R. Poos, P.E.
CONTENTS Page
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1.0 EXECUTIVE SUMMARY 1.1
1.1 Location 1.2
1.2 Ownership 1.2
1.3 Geology 1.3
1.4 Mineralization 1.3
1.5 Exploration 1.4
1.6 Resource Modeling and Estimation 1.5
1.7 Mine Design and Reserve Estimate 1.7
1.8 Development and Operations 1.9
1.8.1 Mine Plan and Operation 1.9
1.8.2 Plant Operation 1.9
1.8.3 Project Economics 1.10
1.9 Conclusions 1.12
1.9.1 Adequacy of Procedures 1.12
1.9.2 Adequacy of Data 1.12
1.9.3 Adequacy of Feasibility Study 1.12
1.9.4 Compliance with Canadian NI 43-101 Standards 1.12
1.10 Recommendations 1.13
2.0 INTRODUCTION AND TERMS OF REFERENCE 2.1
2.1 Qualified Persons and Participating Personnel 2.1
2.2 Terms and Definitions 2.1
2.3 Units 2.2
2.4 Source Documents 2.2
3.0 RELIANCE ON OTHER EXPERTS 3.1
4.0 PROPERTY DESCRIPTION AND LOCATION 4.1
4.1 Property Location 4.1
4.2 Description 4.1
4.3 Ownership 4.1
4.4 Royalties and Exploitation Taxes 4.5
4.5 Environmental Liabilities 4.6
4.6 Status of Required Permits 4.6
5.0 ACCESSIBILITY, CLIMATE, PHYSIOGRAPHY, AND INFRASTRUCTURE 5.1
5.1 Access 5.1
5.2 Climate 5.1
5.3 Physiography 5.1
5.4 Infrastructure 5.2
6.0 HISTORY 6.1
6.1 The Company 6.1
6.2 The Brisas Project 6.1
6.3 Sequence of Studies 6.2
7.0 GEOLOGIC SETTING 7.1
7.1 Project Geology 7.1
7.1.1 District Geology 7.1
7.1.2 Sequence of Units 7.2
7.2 District Structure 7.2
7.2.1 Site Geology 7.4
7.3 Detailed Geology of the Brisas Project 7.5
7.3.1 Rock Units 7.5
7.3.2 Weathered Rock and Saprolite 7.5
7.3.3 Unweathered Rock 7.8
7.3.4 Stratigraphy 7.10
8.0 DEPOSIT TYPES 8.1
9.0 MINERALIZATION 9.1
9.1 Types 9.1
9.1.1 The Blue Whale Body 9.1
9.1.2 Disseminated Au+Pyrite +/-Cu 9.1
9.1.3 Disseminated High Cu/Low Au 9.2
9.1.4 Au-Bearing Shear Zones 9.2
9.1.5 Alteration 9.2
9.1.6 Trace Element Geochemistry 9.4
9.2 Geological Model 9.5
9.2.1 Genesis of Deposit 9.6
9.2.2 Later Remobilization 9.7
10.0 PROJECT EXPLORATION 10.1
10.1 Exploration Model 10.1
11.0 PROJECT DRILLING 11.1
11.1 Drill Hole Collar Surveys 11.3
11.2 Downhole Surveys 11.3
11.3 Core Logging 11.4
11.4 Twin Drilling Verification 11.4
11.5 Condemnation Drilling 11.5
12.0 SAMPLING METHODOLOGY 12.1
12.1 Drilling Sampling 12.1
12.2 Bulk Density Determination Sampling 12.1
13.0 SAMPLE PREPARATION, ANALYSIS, AND SECURITY 13.1
13.1 Drilling Sample Analysis 13.1
13.2 Drilling Sample Check Analysis 13.2
13.3 Density Analysis 13.5
14.0 DATA VERIFICATION 14.1
14.1 Data Verification and Validation 14.1
14.2 Twin Drilling Verification 14.2
15.0 ADJACENT PROPERTIES 15.1
16.0 METALLURGY AND MINERAL PROCESSING 16.1
16.1 Metallurgical Testwork 16.1
16.2 Plant Design 16.5
17.0 MINERAL RESOURCE AND MINERAL RESERVE ESTIMATES 17.1
17.1 Coordinate System, Surveying, and Topography 17.1
17.2 Sample Database 17.1
17.3 Resource Model Setup 17.2
17.4 Mineralized Rock Model 17.3
17.5 Statistical Analysis and Variograms Grade
Estimation and Validation 17.5
17.5.1 Gold Review 17.5
17.5.2 Copper Review 17.8
17.5.3 Summary 17.15
17.6 Grade Estimation and Validation 17.15
17.7 Resource Classification 17.19
17.8 Resource Statement 17.19
17.9 Reserve Estimation 17.20
17.9.1 Optimization Analysis 17.21
17.9.2 Mine Design 17.24
17.9.3 Cutoff Grade 17.28
17.10 Reserve Statement 17.29
17.11 Summary and Conclusions 17.30
17.11.1 Adequacy of Procedures 17.30
17.11.2 Adequacy of Data 17.30
17.11.3 Compliance with Canadian NI 43-101 Standards 17.31
17.11.4 Exploration Potential 17.31
18.0 OTHER RELEVANT DATA AND INFORMATION 18.1
19.0 INTERPRETATION AND CONCLUSIONS 19.1
19.1 Adequacy of Procedures 19.1
19.2 Adequacy of Data 19.1
19.3 Adequacy of Feasibility Study 19.1
19.4 Compliance with Canadian NI 43-101 Standards 19.1
20.0 RECOMMENDATIONS 20.1
21.0 REFERENCES 21.1
22.0 ADDITIONAL REQUIREMENTS FOR DEVELOPMENT PROPERTIES 22.1
22.1 Mining Operations 22.1
22.2 Recoverability 22.2
22.3 Markets and Contracts 22.4
22.4 Environmental Considerations 22.4
22.5 Taxes 22.5
22.5.1 Income Tax 22.5
22.5.2 Value Added Tax 22.6
22.5.3 Resource Taxes 22.6
22.5.4 Customs Duties 22.6
22.6 Capital and Operating Cost Estimates 22.7
22.6.1 Capital Cost Details 22.7
22.6.2 Operating Cost Summary 22.7
22.7 Economic Analysis 22.9
22.8 Base Case Evaluation 22.10
22.8.1 Major Assumptions 22.10
22.8.2 Sensitivity Analysis 22.11
23.0 ILLUSTRATIONS 23.1
24.0 CERTIFICATES OF QUALIFICATION 24.1
TABLES
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1-1 Drilling Summary 1.5
1-2 Mineral Resource Estimate 1.6
1-3 Reserve Estimate Based on Revenue
Cutoffs of $3.04 for Hard Rock & $3.24 for Saprolite 1.8
1-4 Reserve Case and Base Case Economic Evaluation 1.10
1-5 Base Case Key Economic Assumptions and Results 1.11
4-1 Land Status Summary 4.2
11-1 Project Drilling Summary 11.1
11-2 Brisas Concession Drilling Summary 11.3
13-1 Check Assays for High Grade Gold Values 13.2
13-2 Bulk Densities and Moisture Contents by Rock Type 13.5
14-1 Twin Hole Data (Au and Cu Grade) 14.3
14-2 Twin Hole Data (Average Au and Cu Grade Maximums and Minimums) 14.3
16-1 Ore Processing, Ore Types and Grades 16.1
16-2 Ore Processing, Testwork Study 16.4
16-3 Average of the Results for the Locked Cycle Tests 16.4
16-4 Ore Processing, Principal Parameters 16.5
16-5 Ore Processing, Principal Equipment List 16.7
17-1 Drill Hole Database Summary 17.2
17-2 Rock Type and Density Model Codes 17.3
17-3 Block Model Geometry 17.4
17-4 Mineral Envelope Model Codes 17.4
17-5 Variogram Models 17.15
17-6 Capping Grades for 6M Downhole Composites 17.15
17-7 Gold Grade Estimation Parameters 17.16
17-8 Copper Estimation Parameters 17.16
17-9 Mineral Resource Estimate 17.20
17-10 Pit Optimization Parameters from April 2005 17.22
17-11 Metal Recoveries 17.23
17-12 Revenue per Tonne Cutoff Grade Calculation Parameters 17.28
17-13 Parameters for Revenue Model and Gold Equivalent Ratio 17.29
17-14 Reserve Estimate Based on a Revenue
Cutoff of $3.04/t Hard Rock and $3.24/t Saprolite 17.30
22-1 Base Case Key Economic Assumptions and Results 22.8
22-2 Average Operating Cost 22.9
22-3 Reserve Case and Base Case Economic Evaluation 22.10
22-4 Economic Evaluation Base Case and Price Sensitivity 22.12
FIGURES
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4-1 Project General Location Map 4.3
4-2 Concession Map 4.4
7-1 Geological Map of KM 88 District 7.3
7-2 Brisas Concession Geological Map 7.6
7-3 Typical Weathering Column 7.7
7-4 Ternary Diagram for Classification of Tuffaceous Units 7.9
7-5 Stratigraphic Column 7.11
9-1 E-W Section at 683000 N, Lithologic with Au and Cu Mineralized 9.3
11-1 Drill Hole Location 11.2
13-1 Gold Reserves Sample Preparation Flow Sheet 13.3
13-2 High Grade Au Original and Check Assay Comparison 13.4
14-1 Twin Core Hole Locations 14.4
14-2 Twin Core Holes Showing Gold Assays Section 682300 N 14.5
16-1 Simplified Overall Process Flow Diagram 16.8
17-1 Log-Probability Plot of Uncapped 6M Composite 17.6
17-2 Log-Probability of Uncapped Blue Whale Composites 17.7
17-3 Correlogram for Gold Zone 10 - Strike 17.9
17-4 Correlogram for Gold Zone - Dip 17.9
17-5 Correlogram for Gold Mineralized Envelope - Across Dip 17.10
17-6 Correlogram for Blue Whale 17.10
17-7 Log-Probability Plot of Uncapped 6m Composites for all Cu 17.11
17-8 Log-Probability Plot for Blue Whale of Uncapped
6m Composites for Cu 17.11
17-9 Correlogram for Copper Zone 20 - Strike 17.13
17-10 Correlogram for Copper Zone 20 - Dip 17.13
17-11 Correlogram for Copper Zone 20 - Perpendicular to Dip 17.14
17-12 Correlogram for Copper Zone 22 17.14
17-13 Composites and Blocks Au Distribution - Section 682400 N 17.17
17-14 Composites and Blocks Cu Distribution - Section 682700 N 17.18
17-15 Saprolite and Weathered Hard Rock Slope Sectors 17.25
17-16 Fresh Rock Slope Sectors 17.26
17-17 Overall Project Layout 17.27
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1.0 Executive SUMMARY
- ----------------------------------------------------------------------
The Brisas Project is a gold-copper deposit located in the Kilometer 88
mining district of Bolivar State in southeast Venezuela. Before its
acquisition by Gold Reserve Inc. (GRI) in 1992, local owners and also
illegal miners worked the property on a small scale. Shallow pitting
and hydraulic methods were used to mine the upper saprolite zone, and
coarse gold was recovered by gravity concentration. GRI has carried
out a major exploration drilling program on the concession, resulting
in the definition of a large, gold-copper deposit.
The operating plan proposes a large open pit mine containing proven and
probable reserves of approximately 10.4 million ounces of gold and 1.3
billion pounds of copper in 484.6 million tonnes of ore grading 0.67
grams of gold per tonne and 0.13 percent copper, at a revenue cutoff
grade of $3.04 per tonne for hard rock and $3.24 for saprolite. The
revenue cutoffs were based on a gold price of $400 per ounce and a
copper price of $1.15 per pound. The project anticipates utilizing
conventional truck and shovel mining methods with the processing of ore
at full production of 70,000 tonnes per day, yielding an average annual
production of 456,000 ounces of gold and 60 million pounds of copper
over an estimated mine life of approximately 18.5 years.
This Technical Report is based on the Brisas Project Feasibility Study
dated January 2005, with the following Updates:
A new resource model was developed by Pincock, Allen & Holt (PAH) with
the addition of 84 new drillholes in late 2004. The information is
presented in the PAH report "Supplement to the January 2005 Brisas
Feasibility Study", dated November 2005.
A new capital cost estimate with a minor modification to the process
flowsheet was developed by SNC Lavalin to update the feasibility costs
from 4th Quarter 2004 costs to 1st Quarter 2006 costs. The information
is presented in the SNC report "Project Scope and Definition Document",
dated April 2006.
A new mine design and production schedule based on new project costs
was developed by Marston and Marston (Marston). The information is
presented in the Marston report "Brisas Project Resource and Reserve
Update," dated October 2006.
A new project economic model was developed by GRI and validated by
PAH. This model uses updated capital and operating costs and was used
for the economic information presented in this Technical Report.
This Technical Report assumes an economic base case utilizing a
three-year rolling average price of $470 per ounce gold, $7.90 per
ounce silver, and $1.80 per pound copper. At such prices, cash
operating costs (net of copper byproduct credits) are estimated at $142
per ounce of gold and total costs per ounce, including operating costs
and initial and sustaining capital would be $253 per ounce of gold.
Initial capital costs are currently estimated at $638 million with
another $45 million in working capital. All amounts are in U.S.
dollars.
1.1 Location
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The Brisas Project is located in the Kilometer 88 mining district of
Bolivar State in southeast Venezuela at Latitude 6 degrees 10' North
and Longitude 61 degrees 28' West. The property is approximately 3.5
kilometers west of the Kilometer 88 marker on Highway 10. Las Claritas
is the closest town to the property.
The project site is located in the Guyana region, which covers
approximately one-third of Venezuela's national territory. The main
nearby large city is Puerto Ordaz, with approximately 700,000
inhabitants, situated on the Orinoco River near its confluence with the
Caroni River. Puerto Ordaz has major port facilities accessible to
ocean-going vessels from the Atlantic Ocean via the Orinoco, a distance
of about 200 kilometers. There is regularly scheduled airline service
to Puerto Ordaz from various cities within Venezuela.
Highway 10 provides paved access from Puerto Ordaz, which is 373
kilometers northwest of the property, to within 3.5 kilometers of the
project site. Unpaved roads provide the remaining 3.5 kilometers of
access. Upgrading the unpaved roads is part of the infrastructure
improvements plan for the project area.
1.2 Ownership
- ----------------------------------------------------------------------
The main mineralized area at the Brisas Project is contained within the
500-hectare (1,235 acre) Brisas Del Cuyuni alluvial and hardrock
Concession. The Concession measures 2,500 meters (1.5 miles)
north-south and 2,000 meters (1.25 miles) east-west. GRI also controls
several other concessions either adjacent to or near the Brisas
Concession.
According to GRI, mineral ownership consists of Brisas alluvial
production concession originally granted in 1988 and acquired by GRI in
1992 with the acquisition of Compania Aurifera Brisas del Cuyuni S.A.
The hardrock production concession immediately below the alluvial
concession was applied for by GRI in 1993 and was ordered to be issued
by the Ministry of Energy and Mines (MEM) in December 1997. The
concession was granted to GRI in early 1998 and the official record of
"veta" (hard rock) rights was published in the "Gaceta Official De La
Republica De Venezuela" on March 3, 1998. The combined alluvial
concession and hardrock concession are referred to as the Brisas
Concession.
Other applications for mineral rights have been submitted for small
tracts of land immediately adjacent to the Brisas Concessions. These
include the 15-hectare NLNAV1 to the north, the 21-hectare NLEAV1 to
the east and the 32-hectare NLSAV1 to the south. GRI has received the
contract for mineral rights on NLEAV1 and NLSAV1 and has applied for
the rights to NLNAV1.
Additionally, in 1999, GRI acquired the 1,433-hectare (3,541 acres) El
Pauji Concession and contracts with Corporation Venezolana de Guyana
(CVG) for the 4,950-hectare (12,232 acres) Barbara property, the
847-hectare (2,162 acres) Zuleima property and the 1644-hectare (4,062
acres) Lucia property. Early in 2004 Gold Reserve obtained contracts
for the 499-hectare (1,232 acres) Esperanza and the 50-hectare (123
acres) Yusmari properties. Barbara is located approximately 2.6
kilometers (1.6 miles) south of the Brisas Concession and will be the
site for tailings and waste rock disposal facilities. Esperanza, El
Pauji, and Zuleima are located west and south of the Brisas Concession
and will be used for waste rock disposal. The Yusmari property is
adjacent and located on the northeast corner of the Brisas Concession
and is within the ultimate pit boundary. The Lucia property is located
7.8 kilometers southwest of the Brisas Concession and its use for the
Project is yet to be determined.
In 2005, GRI was granted the rights to explore and develop a rock
quarry in the 400-hectare Barbarita concession. This concession is
located totally within the Barbara property in the northeast corner.
1.3 Geology
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The Brisas Project is within the Guayana Shield in northern South
America. The shield covers easternmost Colombia, southeastern
Venezuela, Guyana, Suriname, French Guiana and northeastern Brazil.
The Venezuelan portion of the shield is subdivided into five geological
provinces with different petrological, structural and metallogenic
characteristics. The provinces are, from oldest to youngest, Imataca,
Pastora, Cuchivero, Roraima, and Parguaza. Only the Imataca, Pastora
and Roraima provinces are found in the vicinity of the Brisas deposit.
The Brisas Concession itself lies within a portion of the lower
Caballape Formation volcanic and volcanic-related sedimentary rocks.
The units present are (1) andesitic to rhyolitic tuffaceous volcanic
beds, (2) related sedimentary beds, and (3) a tonalitic intrusive
body. All rocks have been tilted and subjected to lower greenschist
facies metamorphism. In the main mineralized trend, moderate to strong
foliation is oriented N 10 E and dipping 30 to 55 degrees NW. This
foliation appears to be parallel to the original bedding and tends to
be strongest in the finer-grained rocks. A much weaker foliation
orientation appears in outcrop exposures, striking NNW and dipping to
the SW.
Dikes and quartz veins cut the lower Caballape Formation. The strata
and intrusive rocks are cut by N30W striking mafic dikes emplaced at
regular intervals (200-600 meters), some of which have displacement on
the order of tens of meters. Quartz veins populate the concession and
have been noted both in outcrop and in drill intersections. The most
common are sets of thick, boudinaged, and en echelon vein structures
that follow foliation/bedding orientation. They are thought to relate
in part to movement of quartz during metamorphism. Other quartz veins
exist in various orientations within the property.
1.4 Mineralization
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There are four distinct types of Au and Cu mineralization present in
the concession, defined by geometry, associated minerals, and the Au/Cu
ratio. These zones are the Blue Whale body, disseminated
gold+pyrite+/-Cu, disseminated high Cu, and shear-hosted Au.
The Blue Whale mineralized body is a discrete, sharply bounded,
flattened, cigar-shaped feature that trends more or less parallel to
the local schistosity and plunges about 35 degrees SW along
foliation. It is 20 meters in diameter at its widest point, and tapers
off at depth. It is volumetrically a small fraction of the economically
mineralized ground in the Brisas Project, but it possesses the highest
Au and Cu grades.
The bulk of ore mineralization occurs in disseminated, coalescing,
lensoid bodies high in Au and in most cases low in Cu. These bodies
lie almost exclusively in the lapilli-rich, rapidly alternating
sequence of tuffaceous units and are clearly aligned along foliation.
Together, these lenses form a generally well defined mineralized band
which mimics the dip of the foliation/bedding and remains open at
depth. It remains at a similar thickness from the northern concession
boundary for a distance of 1.4 kilometers south, after which it tapers
rapidly. Alteration minerals characteristic of these lenses are
epidote, chlorite, secondary biotite, and sericite.
The Au in the stratiform lenses is highly disseminated but only roughly
associated with high occurrences of pyrite. Fine-scale sub-sampling of
3-meter assay intervals indicates good correlation between Au and small
(<1 cm) calcite/quartz veins. Correlation also exists with zones of
high occurrence of epidote and in lapilli-sized lithic fragments that
have been partially to completely replaced by epidote and sulfides.
Sub-sampling evidence also suggests that Au is more evenly distributed
through the rock near the center of the large mineralized lenses than
it is near the margins.
Stratiform lenses of high Cu (with or without high Au) parallel and
underlie the Au+pyrite lenses described above. These lenses outcrop in
the northern part of the deposit, and plunge to the south along the
bedding/foliation in a manner similar to the Blue Whale and high Au/low
Cu lenses. Rock in the mineralized zones is characterized by a high
degree of lapilli and crystal replacement by chalcopyrite, and in some
cases, by bornite and covellite. High chalcopyrite in the rock matrix
is often accompanied by high chlorite, secondary biotite, and in some
cases molybdenite.
Shear-hosted gold occurrences exist in the southern part of the
concession, running parallel to the foliation as with mineralization
further north. Stratigraphically, they occur above the large
disseminated lenses previously described. The gold grades are erratic
and localized, up to 100 g/t Au over a 3-meter core interval. There is
a high degree of correlation between chalcopyrite and Au grade, though
Cu grades in these shears are sub-economic.
1.5 Exploration
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GRI began exploration activity in late 1992 and continued various
drilling programs through the present time. A total of 977 drill holes
with a total drilled length of 207,751 meters have been completed by GRI
at Brisas as of September 2006. Of these holes 802 representing 189,985
meters of drilling were drilled specifically for exploration on the
Brisas Concession. The remaining holes were drilled for hydrologic,
geotechnical, and metallurgical testing. In some cases the test holes
were assayed and used in modeling.
Drill hole spacing within and around the planned pit area is about 50
meters or less. Drill hole spacing in the Disseminated High Cu/Low Au
and Blue Whale areas is about 25 meters. The majority of the
exploration drilling was performed using standard diamond core-barrel
recovery techniques although some auger drilling was carried out at the
beginning of the exploration campaign. Auger holes (A holes) are
generally very shallow and are scattered throughout the project area
and in between later-drilled core holes; many auger holes are outside
the pit area. Also, about half of the auger holes were deepened using
regular core hole drilling techniques (AD holes). Auger holes were
included in the resource estimation process.
The resource/reserve estimate presented in this report includes
drilling results up to hole D845 drilled in March 2005. A summary of
drilling at the Brisas Project from 1993 through 2006 is shown in Table
1-1. The drilling also included drill holes for metallurgical,
geotechnical, hydrological testing, and independent verification.
Condemnation drilling has been performed in the waste dump areas, and
to a limited extent, in the tailings dam area. None of the drill
results in the tailings dam area has yielded geological or geochemical
information suggestive of potential ore deposits.
TABLE 1-1
Gold Reserve Inc.
Brisas Project, Venezuela
Feasibility Update
Drilling Summary
Auger Auger-Diamond Diamond
Year Drilling Drilling Drilling Total
------------- ------------- ------------- -------------
Holes Meters Hole Meters Hole Meters Holes Meters Comments
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1993 14 404 3* 77 36 5,120 50 5,601
1994 57 1,528 59 12,649 5 422 121 14,600
1995 - - 9 1,926 99 18,997 108 20,923
1996 - - - - 252 50,221 252 50,221
1997 - - - - 219 67,946 219 67,946
1999 - - - - 13 5,726 13 5,726
2003-2004 - - - - 126 34,670 126 34,670
2005 - - - - 20 2,291 20 2,291 Non-Exploration Not in Model
2006 - - - - 68 5,775 68 5,775 Non-Exploration Not in Model
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Total Drilling 71 1,932 68 14,652 838 191,168 977 207,751
=================================================================================
Note: * Auger completed but not counted until diamond portion completed in 1994.
1.6 Resource Modeling and Estimation
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It has been observed for some time within the Brisas Project that the
mineralization generally follows a structural trend that is
sub-parallel to the rock units' trend present in the area. Therefore,
the resource model is based on constructing separate mineral envelopes
for Au and Cu that follow the general geologic trend and structural
control of the Brisas zone and, in the case of copper, the weathering
profile as well. The Blue Whale is modeled separately.
Variograms were run on the drill hole data to evaluate the spatial
variability and lateral grade continuity through the deposit and
provide limits for the search radius used in the grade interpolation
process. PAH ran variograms for both Au and Cu downhole composites.
Three-dimensional variograms were run for different orientations
including strike, dip, and across the ore zones.
Gold and copper composite values were capped according to the
statistical review of the data to prevent outlying values from
unnecessarily influencing the model toward higher gold and copper
values. PAH does not believe that the composite grade capping will
have a great influence on the overall model, but it could locally
prevent grade overestimation.
The gold and copper grade interpolations for the mineral envelopes only
used the 6-meter down-hole composites that fell within the grade
envelopes. Only blocks within the grade envelopes received an Au or a
Cu grade. The ordinary kriging (OK) interpolation method was used for
all runs.
Table 1-2 tabulates the measured, indicated and inferred resources at
the Brisas Project and shows the tonnage/grade variability at various
gold equivalent (AuEq) cutoff grades. Gold equivalent calculations are
based on metal prices of $400/ounce Au, and $1.15/lb Cu, anticipated
metal recoveries, and smelter costs.
The measured and indicated resource at a 0.4 AuEq cutoff grade is
estimated as 573.9 million tonnes at a gold grade of 0.66 gpt and a
copper grade of 0.13 percent. In addition, the inferred resource at
the Brisas Project is estimated as 114.9 million tonnes at 0.59 gpt
gold grade and 0.12 percent copper grade at a 0.4 AuEq cutoff grade.
The inferred resources include the inferred mineralization both within
and outside the mineral envelopes. This resource estimate is inclusive
of the reserve estimate.
TABLE 1-2
Gold Reserve Inc.
Brisas Project, Venezuela
Feasibility Update
Mineral Resource Estimate
Gold Copper
AuEq -------------- --------------
Category Cutoff k tonnes gpt k ozs % M lbs
- ---------------------------------------------------------------
0.3 285,405 0.634 5,817 0.114 717
0.4 250,565 0.686 5,527 0.119 657
Measured 0.5 207,448 0.755 5,034 0.126 576
0.6 165,410 0.834 4,437 0.135 492
0.7 129,741 0.918 3,830 0.144 412
0.3 391,430 0.565 7,110 0.126 1,087
0.4 323,371 0.637 6,621 0.130 927
Indicated 0.5 258,354 0.717 5,952 0.135 769
0.6 201,578 0.802 5,198 0.140 622
0.7 154,756 0.893 4,441 0.145 495
0.3 676,835 0.594 12,927 0.121 1,804
Measured 0.4 573,936 0.658 12,148 0.125 1,584
+ 0.5 465,802 0.734 10,986 0.131 1,345
Indicated 0.6 366,988 0.816 9,635 0.138 1,114
0.7 284,497 0.904 8,271 0.145 906
Note: AuEq based on the "Smelter Case". AuEq = Au (gpt) + Cu (%) * 1.16
Gold Copper
AuEq -------------- --------------
Category Cutoff k tonnes gpt k ozs % M lbs
- ---------------------------------------------------------------
0.3 161,853 0.482 2,508 0.115 410
0.4 114,937 0.590 2,182 0.116 294
Inferred 0.5 84,319 0.691 1,873 0.116 216
0.6 60,928 0.801 1,569 0.112 150
0.7 45,770 0.896 1,319 0.111 112
Note: AuEq based on the "Smelter Case". AuEq = Au (gpt) + Cu (%) * 1.16
(*) Inferred resources include both within and outside the mineral envelopes.
The resource estimate included in this report conforms to international
standards such as the Canadian Institute of Mining (CIM) definitions as
adopted by Canadian National Instrument NI 43-101, and the current
drill hole database is sufficient for generating a feasibility level
resource model.
1.7 Mine Design and Reserve Estimate
- ----------------------------------------------------------------------
The Brisas Project is an open-pit gold-copper mining project, which
will utilize hydraulic shovels and 236-tonne trucks as the primary
mining equipment. Based on the results of optimization analysis, an
ultimate pit was designed. A production schedule was then developed
based on a nominal 50/50 blend of the two hard-rock ore types. This
schedule resulted in an average production rate of 25.2 million tonnes
of hard rock ore and on average 51.8 million tonnes of waste per year
over the 18.5 years of the project. During the first four years of the
project, 9.6 million tonnes of oxide saprolite ore and 13.1 million
tonnes of sulfide saprolite ore are mined. This saprolite material is
stockpiled separately. The sulfide saprolite is fed to the crusher at
a rate of 1.95 million tonnes per year. Oxide saprolite is fed to the
mill at a rate of 0.25 mtpy while the sulfide saprolite is processed.
When milling of sulfide saprolite is completed, the oxide saprolite
rate is increased to 0.70 Mtpy.
There are two hard rock ore types, which are referred to as North and
South. Although the names imply a geographic relationship the two ores
are actually defined based on the copper content. North ore is a
gold-chalcopyrite-pyrite with a copper content greater than or equal to
0.05 percent. South ore is a gold-pyrite with a copper content less
than 0.05 percent. In general the ore types split at 681,800 North
coordinate; however, both occur on either side of this line.
Design of the ultimate pit was based on the results of a Whittle
Lerchs-Grossmann (LG) pit shell analysis. Whittle is a software
package that uses the LG algorithm to determine the approximate shape
of a near-optimal pit shell based on applied cutoff-grade criteria and
pit slopes. These shells are generated from the geologic grade models,
and economic and physical criteria.
In the Whittle analysis, for the ultimate pit design, the pit shells
were allowed to cross the northern Brisas Concession boundary. All of
the material in this area was treated as waste rock. Allowing the
crossover into the Cristinas Concession area maximizes the metal
recovery on the Brisas Concession.
Since the Brisas Project has two primary metals, gold and copper, a
cutoff grade based on a single metal does not account for the value
provided by the other metal. As a result, the revenue cutoff grades of
$3.04 per tonne for hard rock and $3.24 per tonne for saprolite were
used to estimate reserves. Revenue of this amount covers the costs for
processing, general and administration, reclamation, stockpile re-handle
for saprolite and selling. Mining costs are not included since an
incremental cutoff assumes mining is a sunk cost.
Using the revenue per tonne cutoff grades of $3.04 and $3.24 based on
metal prices of $400 per ounce for gold and $1.15 per pound for copper,
reserves for the ultimate pit were calculated. Total proven and
probable reserves for the Brisas Project are estimated at 484.6 million
tonnes of ore at a gold grade of 0.67 grams per tonne and a copper grade
of 0.13 percent. There are a total of 952.3 million tonnes of waste in
the pit resulting in a strip ratio (waste/ore) of 1.96. Table 1-3
summarizes these reserves by category.
Table 1-3
Gold Reserve Inc.
Brisas Project, Venezuela
Feasibility Update
Reserve Estimate Based on Revenue Cutoffs of $3.04 for
Hard Rock & $3.24 for Saprolite
Au Au Au Cu Cu
Reserve Tonnage Grade grams ounces Grade Cu M
Category (000's) g/t (000's) (000's) percent tonnes pounds
- ------------------------------------------------------------------------
Proven 226,252 0.69 156,517 5,032 0.12 272,376 600
Probable 258,398 0.64 166,628 5,357 0.13 334,397 737
Total Ore 484,649 0.67 323,145 10,389 0.13 606,773 1,338
- ------------------------------------------------------------------------
Waste 952,304 Strip Ratio 1.96
Total In-Pit 1,436,953
Note: Revenue is based on metal prices of $400/oz for gold & $1.15/lb
for Copper.
PAH believes that the reserve estimate shown in Table 1-3 is reasonable
and meets the definitions as stated by Standards for Disclosure for
Mineral Projects, Form 43-101F1 and Companion Policy 43-101CP dated
December 23, 2005.
The reserve estimate in Table 1-3 is based on the assumption that the
pit backslope extends onto the Las Cristinas Concession, which will
require a backslope agreement. GRI received approval of its operating
plan from MEM in February 2003, which included the extension of the
backslope onto the Las Cristinas Concession. Also in October 2006, GRI
and Crystallex International Corporation (Crystallex) proposed to MARN
to move a water diversion channel on the southern part of the Las
Cristinas Concession, further northward, away from the Brisas pit.
This proposal, if approved, should allow GRI to formalize a backslope
agreement. Crystallex has been granted an operations contract to the
adjacent Las Cristinas property (see section 15.0 Adjacent Properties).
PAH has not reviewed the GRI MEM approved 2003 operating plan or
Crytallex's proposed diversion channel. According to GRI, Corporacion
Venezolana de Guyana (CVG) and MIBAM has indicated to GRI that a
backslope agreement is probable. PAH believes that the backslope
assumption is valid because backslope agreements are a common practice
in the mining industry and the government agencies have been favorable
toward an agreement. Also, the backslope agreement would allow Las
Cristinas/CVG to mine onto the Brisas Concession in the event its mine
plan reaches the border area first. Discussions with MIBAM/CVG are
ongoing. In the event an agreement is not reached, the reserve
estimate will have to be reduced significantly.
1.8 Development and Operations
- ----------------------------------------------------------------------
1.8.1 Mine Plan and Operation
- ----------------------------------------------------------------------
A mine production schedule based on open-pit mining methods utilizing
hydraulic shovels and 236-tonne trucks was developed. Additionally,
the schedule targeted a 0.1 percent average copper grade to produce a
24 percent copper concentrate grade with a blend of the two hard rock
ores. Overall the split between these two ore types is 57 percent
northern hard rock and 43 percent southern hard rock. Because of this
split the target was to have at least 50 percent northern hard rock.
Both of the saprolite ores are stockpiled since they have to be mined
at a rate that exceeds their milling rate in order to meet the hard
rock ore production requirements. Oxide saprolite ore mining is
completed in Year 3 but milling is not completed until Year 19. Mining
of sulfide saprolite ore ends in Year 6 but milling is not completed
until Year 7. Plans are for the hard rock to be dumped directly into
the primary crusher, near the pit exit on the east side, to minimize
stockpiling and re-handling.
All of the waste rock, except that used for tailings dam construction,
will be disposed of in the waste rock dump located to the west of the
pit. There is the potential for the waste rock dump to be located
over the downdip extension of the existing ore body. However,
stripping requirements would likely prevent the pit from economically
expanding into the waste disposal area.
Plans are for the Brisas Mine to operate two 12-hour shifts per day, 7
days per week for a total of 14 shifts per week. It is envisioned that
mining of ore would occur on both shifts in order to minimize
stockpiling and re-handling. Scheduled work time is 10.5 hours per
shift which allows 30 minutes for meals, 30 minutes of delays, and 30
minutes lost during shift change.
1.8.2 Plant Operation
- ----------------------------------------------------------------------
The plant will operate an estimated 360 days per year with 90 percent
availability. Hard rock ore will be processed at a design rate of
3,240 dry tonnes per hour, or 70,000 dry tonnes per day. The hard rock
blend will average 57 percent North and 43 percent South ore, equivalent
to 25.2 million tonne per annum. Additionally, 5,400 tonnes per day of
sulfide saprolite and 2,000 tonnes per day of oxide saprolite will be
processed until these resources are exhausted.
Average concentrate production over the life of the mine will be
117,000 tonnes per year at a grade of 24 percent copper and 90 g/t of
gold and 103 g/t silver. The gold content of the concentrate averages
343,000 oz/yr. Gold recovered as gravity concentrate and as dore metal
produced by cyanide leaching will average 123,000 oz/yr, silver in the
dore will average 84,000 oz/yr.
Tailings will be stored in a 7.5-million-square-meter tailings pond.
About 8 percent of the tailings will be from the cyanidation plant and
will be subjected to Air-SO2 cyanide destruction before being combined
with the flotation concentrator tailings for discharge to the tailings
pond.
1.8.3 Project Economics
- ----------------------------------------------------------------------
A Base Case economic analysis was prepared for the Brisas Project using
a gold price of $470 per ounce, copper price of $1.80 per pound, and
silver price of $7.90 per ounce. The Base Case is based on the
three-year rolling average for metal prices as of September 2006.
Results for the Base Case are summarized in Table 1-4. Table 1-5
provides a summary of some of the key assumptions and additional detail
on the results of the analysis. Cash operating costs are presented for
gold on a net of by-product credit basis. Capital costs are in Table
1-5. Project payback is just under seven years.
Development of the project yields a pre-tax discounted cash flow rate
of return of 15.4 percent and a net present value of $783 million (5
percent discount rate) at a gold price of $470/oz, a silver price of
$7.90/oz, and a copper price of $1.80 per pound. Total pre-tax cash
flow is $1.91 billion.
Likewise, the Brisas Project yields an after-tax discounted cash flow
rate of return of 11.4 percent and a net present value of $445 million
(5 percent discount rate) at a gold price of $470/oz, a silver price of
$7.90/oz, and a copper price of $1.80 per pound. Total after-tax cash
flow is $1.28 billion.
TABLE 1-4
Gold Reserve Inc.
Brisas Project, Venezuela
Feasibility Update
Reserve Case and Base Case Economic Evaluation
Reserve Base
Case Case
- --------------------------------------------------------------
Gold Price ($/troy oz) $400 $470
Copper Price ($/pound) $1.15 $1.80
Silver Price ($/troy oz) $0.00 $7.90
Project Economics Pre-Tax ($ millions)
Cash Flow 713 1,906
NPV @ 5% 120 783
NPV @ 10% (135) 268
IRR 6.9% 15.4%
Project Economics After Tax ($ millions)
Cash Flow 497 1,283
NPV @ 5% 8 445
NPV @ 10% (199) 66
IRR 5.1% 11.4%
Cash Operating Cost ($ per oz Gold)1 $213 $142
Payback (years) 11.6 6.7
(1) Net of copper by-product credit and includes production taxes.
TABLE 1-5
Gold Reserve Inc.
Brisas Project, Venezuela
Feasibility Update
Base Case Key Economic Assumptions and Results
Base Case Assumptions
- --------------------------------------------------------------
Daily Mill Throughput 70,000 tonnes/day
Mine Life 18.5 Years
Gold Price $470/troy ounce
Copper Price $1.80/pound
Silver Price $7.90/troy ounce
Metallurgical Recovery
Plant Recovery - Gold 82.7%
Plant Recovery - Copper 86.8%
Net Payable Metal - Gold 81.0%
Net Payable Metal - Copper 83.2%
Life of Mine Production
Payable Gold 8.41 million troy ounces
Payable Copper 1,113 million pounds
Average Annual Production
Payable Gold/year 456,000 troy ounces
Payable Copper/year 60 million pounds
Initial Capital Cost 1 (in millions US 2006 $)
- --------------------------------------------------------------
Mine $76.6
Mill $241.5
Tailings $14.1
Infrastructure $65.8
Owners Costs $65.3
Pre-Stripping $18.3
Indirect Costs (includes EPCM and Camp) $97.0
Contingency $59.4
Total Initial Capital $638.0
Initial Working Capital $44.5
Capital Costs (in millions US 2006 $)
- --------------------------------------------------------------
Initial $682.5
Sustaining Capital $157.2
Reclamation Expenditure $36.4
Total Capital $876.1
Cash Operating Costs Per Ore Tonne (in US 2006 $)
- --------------------------------------------------------------
Mining and Dewatering $2.08
Processing $2.59
G & A $0.42
Transportation & Freight $0.34
Smelting & Refining $1.02
Total Cash Operating Cost/Ore Tonne $6.45
Cost Per Ounce of Gold
- --------------------------------------------------------------
Cash Operating Costs2 $126
Exploitation Tax $16
Capital Cost (initial and sustaining) $111
Total Costs2 $253
Total Costs3 Excluding Sunk Costs $245
(1) A value added tax (VAT) of 14% or $73 million, is not included in
the initial capital as it should be recovered within the first few
years of construction and mining.
(2) Net of copper by-product credit.
(3) Net of copper credit and excluding, for purposes of the economic
model, sunk costs of approximately $70 million. Total expenditures,
capitalized and costs expensed, on the Brisas Project since its
acquisition by the Company in 1992 totals over US$100 million.
The total initial capital is approximately $638 million, with an
additional $45 million in initial working capital and $157 million of
sustaining capital required over the 19 year mine life. The cash
operating cost per gold ounce produced is $126 after by-product
credits. When additional production taxes and preproduction stripping
are added to the capital costs, total cash and non-cash costs
(fully-loaded) are $253 per ounce.
Reserve estimates were based on a gold price of $400 per ounce, copper
price of $1.15 per pound, and no silver credits. Results from the
economic analysis at these prices are shown in Table 1-4. Since an
after tax total cash flow of $497 million is achieved the economic
criteria for the reserve statement are met.
1.9 Conclusions
- ----------------------------------------------------------------------
1.9.1 Adequacy of Procedures
- ----------------------------------------------------------------------
PAH and various other firms and independent consultants have reviewed
the methods and procedures utilized by GRI at the Brisas Project to
gather geological, geotechnical, and assaying information and found
them reasonable and meeting generally accepted industry standards for a
bankable feasibility level of study.
1.9.2 Adequacy of Data
- ----------------------------------------------------------------------
PAH believes that the Brisas Project has conducted exploration and
development sampling and analysis programs using standard practices,
providing generally reasonable results. PAH believes that the
resulting data can effectively be used in the subsequent estimation of
resources and reserves.
1.9.3 Adequacy of Feasibility Study
- ----------------------------------------------------------------------
This Technical Report is based on the January 2005 Feasibility Study
prepared by Aker Kvaerner, the supplement to the January 2005 Brisas
Project Feasibility Study prepared by PAH dated November 2005, the
Project Scope and Definition Document prepared by SNC Lavalin dated
April 2006, and the Brisas Resource and Reserve Update prepared by
Marston dated October 2006. PAH believes that this Feasibility Study
and subsequent updates have been prepared using standard industry
practices and provides reasonable results and conclusions.
1.9.4 Compliance with Canadian NI 43-101 Standards
- ----------------------------------------------------------------------
PAH believes that the current drill hole database is sufficient for
generating a feasibility level resource model for use in resource and
reserve estimation. Recovery and cost estimates are based upon
sufficient data and engineering to support a reserve statement.
Economic analysis using these estimates generates a positive cash flow,
which supports a reserve statement.
At a 0.4 gpt AuEq cutoff grade the measured and indicated resource is
573.9 million tonnes at a gold grade of 0.66 gpt and a copper grade of
0.13 percent. Included in this resource is a proven and probable
reserve of 484.6 million tonnes of ore at a gold grade of 0.67 gpt and
a copper grade of 0.13 percent based on a value cutoff of US$3.04 per
tonne for hard rock and $3.24 per tonne for saprolite.
PAH believes that the resource and reserve estimates have been
calculated utilizing acceptable estimation methodologies. The
classification of measured and indicated resources, stated in Table
1-2, and proven and probable reserves, stated in Table 1-3, meet the
definitions as stated by Standards for Disclosure for Mineral Projects,
Form 43-101F1 and Companion Policy 43-101CP dated December 23, 2005.
1.10 Recommendations
- ----------------------------------------------------------------------
The Brisas Project Feasibility Study dated January 2005 and the
subsequent updates provide reasonable results and conclusions and meet
the requirements of a Feasibility Study. As the project continues to
move from the feasibility stage into the design and construction phases
there are areas of the project that should be given additional
consideration beyond what has been completed so far. Below is a list
of recommendations to consider as the project advances:
Additional geotechnical studies to evaluate steepening the pit slopes
should be investigated. At the present time Vector Colorado LLC., is
completing a detailed study of pit slope stability. Six oriented core
holes have been drilled. An acoustic televiewer has been used on four
of the holes to demonstrate fracture orientation. A report is in
progress and will be finalized in the 4th Quarter of 2006.
PAH recommends additional testwork on the oxide saprolite ores to see
if there is any detrimental effect on the sulfide ore flotation by
adding the oxide ores to the flotation circuit PAH recommends
conducting bench-scale batch grinding and flotation tests with the
following ore blends:
Test 1 Test 2
-------------- -----------
Hard Rock, North ore 50% 51%
Hard Rock, South ore 41% 42%
Sulfide saprolite 6% 7%
Oxide saprolite 3% 0%
PAH recommends a geochemical assessment of the potentially
acid-generating material in the waste rock piles to determine long-term
treatment options. Studies thus far show that the overall material has
a net neutralizing potential, and 250 additional ABA tests have been
conducted. A geochemical model is being developed to address the
makeup of the surface and ground waters over the life of the project.
2.0 Introduction and Terms of Reference
- ----------------------------------------------------------------------
Pincock, Allen and Holt (PAH) was retained by Gold Reserve Inc. (GRI)
to write a Technical Report, that meets Canadian National Instrument
43-101 requirements for the Brisas Project, in the Km 88 region of
Venezuela. This report was prepared for disclosure of the results of
the studies that have been completed since the January 2005 Brisas
Project Feasibility Study. The resource and reserve estimates were
conducted in accordance with the Standards for Disclosure for Mineral
Projects, Form 43-101F1 and Companion Policy 43-101CP dated December
23, 2005.
Previous work by PAH on the Brisas Project includes the preparation of
the resource model, mine plans, resource and reserve estimates, and
economic model for the Brisas Project Feasibility Study of January 2005
(Feasibility) by Aker Kvaerner (AK). Additionally, in November 2005 PAH
issued a supplement to the Feasibility based on additional drill hole
information. This resource model is the same as that used in this
report. Marston has used the PAH resource model to develop a new mine
design, production schedule, and resource and reserve estimates.
2.1 Qualified Persons and Participating Personnel
- ----------------------------------------------------------------------
The principal authors of this report are Susan Poos, Richard Addison,
and Richard Lambert, all registered professional engineers.
Ms. Poos has been involved with the project since January 2004. In
February 2004, she visited the project site. Ms. Poos was responsible
for the development of the resource and reserve estimates reported in
the Feasibility and this Technical Report. She was also responsible
for developing the mine design and production schedules on which the
reserve estimate was based.
Mr. Addison reviewed the metallurgy and processing portions of the
Feasibility that were written by AK and the Project Scope and
Definition Document by SNC. Based on this review he wrote the
applicable sections of this report.
Mr. Lambert developed the mine capital and operating cost estimates, as
well as the economic model for the Feasibility, he has updated the
capital and operating costs in the current economic model. He has
provided the corresponding sections for this report.
2.2 Terms and Definitions
- ----------------------------------------------------------------------
GRI refers to Gold Reserve Inc., PAH refers to Pincock, Allen & Holt
and its representatives, SNC refers to SNC Lavalin, Marston refers to
Marston & Marston, Inc. and its representatives, AK refers to Aker
Kvaerner Metals Inc., BGC refers to Bruce Geotechnical Consultants,
Inc., Vector refers to Vector Colorado, LLC. Brisas Project refers to
the Brisas del Cuyuni Project located near Km88, Venezuela including
the proposed mine area, process plant location, and other related
facilities. Brisas Concession refers to the Brisas alluvial concession
and the Brisas hard rock concession beneath the alluvial concession.
CVG refers to Corporation Venezolana de Guyana, MEM refers to Ministry
of Energy and Mines, MIBM refers to the Ministry of Basic Industries
and Mining, a new ministry that resulted from the recent reorganization
of MEM, and MARN refers to the Ministry of Environmental and Natural
Resources. Feasibility or Feasibility Study refers to the Brisas
Project Feasibility Study of January 2005 prepared by Aker Kvaerner of
Houston. Supplement refers to the Supplement to the January 2005
Brisas Feasibility Study prepared by PAH and dated November 2005. Au
is the abbreviation for gold. Cu is the abbreviation for copper. Ag
is the abbreviation for silver.
Resource and Reserve definitions are as set forth in Canadian Institute
of Mining, Metallurgy and Petroleum, CIM Standards on Mineral Resource
and Mineral Reserves - Definitions and Guidelines adopted by CIM
Counsel on December 11, 2005.
2.3 Units
- ----------------------------------------------------------------------
All capital and operating costs are in first quarter 2006 United States
dollars ($) unless otherwise noted. Commodity prices are in United
States dollars ($) unless otherwise noted. Precious metal grades are
described in terms of grams per metric tonne (g/t or gpt), with
tonnages stated in dry metric tonnes. Copper grades are stated in
terms of weight percent based on dry metric tonnes.
Salable precious metals are described in terms of troy ounces. Salable
copper is described in terms of pounds or metric tonnes, as noted.
2.4 Source Documents
- ----------------------------------------------------------------------
The source documents for this report are:
Las Brisas Pre-feasibility Study dated February 1988 prepared by
J.E.MinCorp for GRI.
Brisas Del Cuyuni Project Review of 250 Million Tonne Pre-feasibility
Open Pit dated April 1999 by BGC for GRI.
Brisas Project Feasibility Study dated January 2005 prepared by AK for GRI.
Supplement to the January 2005 Brisas Feasibility Study dated November
2005 prepared by PAH for GRI.
Project Scope & Definition Document dated April 2006 prepared by SNC
for GRI
Brisas Project Resource & Reserve Update dated October 2006 prepared by
Marston for GRI
3.0 RELIANCE ON OTHER EXPERTS
- -----------------------------------------------
This report was prepared for Gold Reserve Inc. (GRI) by the independent
consulting firm of Pincock, Allen & Holt (PAH), to report the results of
an update to the Brisas Project Feasibility Study that was completed in
January 2005. This Technical Report is based largely on information
originally presented in the January 2005 Feasibility Study by Aker
Kvaerner (AK), for which PAH provided the geology, mining, and economic
sections under a subcontract to GRI. Information contained in this
report is based on information available to PAH at the time of the
report, including information generated by PAH as well as information
supplied by GRI and other third party sources. PAH believes that the
information contained herein will be reliable under the conditions and
subject to the limitations set forth herein. PAH does not guarantee
the accuracy of third party information that was reviewed by PAH,
including property legal title information, geotechnical issues,
environmental issues, and process issues.
This TR is based in part on information prepared by other parties. PAH
has relied primarily on information provided as part of the following
reports:
BGC Engineer Inc., April 29, 1999, Brisas Del Cuyuni Project Review of
250 Million Tonne Pre-Feasibility Open Pit
J.E. MinCorp, a division of Jacobs Engineering Group, Inc., February
1988, Las Brisas Pre-Feasibility Study
Aker Kvaerner Metals Inc., January 2005, Brisas Project Feasibility
Study
SGS Lakefield Research Limited, February 1, 2005, An Investigation of
Copper and Gold Recovery from Las Brisas Samples
Vector Colorado, LLC, December 2005, Hydrology and Pit Dewatering
Addendum 1
AATA International, December 2005, Environmental and Social Impact
Assessment, Final Draft Version 1.03.
SNC Lavalin, April 2006, Project Scope & Definition Document
PAH believes that this information is reliable for use in this report.
PAH has not conducted land and mineral rights legal title evaluations
and has relied on information provided by Gold Reserve pertaining to
property ownership, which PAH believes is reliable. PAH has not
conducted detailed permitting evaluations required by Venezuelan Mining
and Environmental Laws, for which PAH has only relied on public reports,
opinions, verbal assessments, third party reports, and confirmations by
Gold Reserve personnel who are experienced professionals, which PAH
believes to be accurate.
4.0 Property, Description and Location
- ----------------------------------------------------------------------
The Brisas Project is located in the Km 88 mining district of Bolivar
State in south-eastern Venezuela (Figure 4-1). This section presents
information on the property location, description, and ownership.
Additionally, it provides information on environmental liabilities and
permitting requirements.
Information in this section on land status and legal title were
provided to PAH by GRI. PAH has not conducted a detailed review of the
land status and legal title.
4.1 Property Location
- ----------------------------------------------------------------------
The Brisas Project is located in the Km 88 mining district of Bolivar
State in south-eastern Venezuela at Latitude 6 degrees 10 feet North
and Longitude 61 degrees 28 feet West, (Figure 4-1). The property is
approximately 3.5 kilometers west of the Km 88 marker on Highway 10.
Las Claritas is the closest town to the property.
4.2 Description
- ----------------------------------------------------------------------
The main mineralized area at the Brisas Project is contained within the
500-hectare (1,235 acre) Brisas Concession. The Concession measures
2,500 meters (1.5 miles) north-south and 2,000 meters (1.25 miles)
east-west. GRI also controls several other concessions either adjacent
to or near the Brisas Concession. Table 4-1 summarizes the status of
the concessions controlled by GRI. These concessions are shown in
Figure 4-2.
4.3 Ownership
- ----------------------------------------------------------------------
According to GRI, mineral ownership consists of the Brisas alluvial
production concession originally granted in 1988 and acquired by GRI in
1992 with the acquisition of Compania Aurifera Brisas del Cuyuni C.A.
The hardrock production concession immediately below the alluvial
concession was applied for by GRI in 1993 and was ordered to be issued
by the Ministry of Energy and Mines (MEM) in December 1997. The
concession was granted to GRI in early 1998 and the official record of
"veta" (hard rock) rights were published in the "Gaceta Official De La
Republica De Venezuela" on March 3, 1998.
Other applications for mineral rights have been submitted for small
tracts of land immediately adjacent to the Brisas Concessions. These
include the 15-hectare NLNAV1 to the north, the 21-hectare NLEAV1 to
the east and the 32-hectare NLSAV1 to the south. GRI has received the
contract for mineral rights on NLEAV1 and NLSAV1 and has applied for
the rights to NLNAV1.
In 1999, GRI completed acquisition of the 1433-hectare (3541 acres) El
Pauji concession and contracts with Corporacion Venezolana de Guyana
(CVG) for the 4,950-hectare (12,232 acres) Barbara property, the
844-hectare (3,086 acres) Zuleima property and the 2.5-hectare (6
acres) Lucia property.
TABLE 4-1
Gold Reserve Inc.
Brisas Project, Venezuela
Feasibility Update
Land Status Summary
Occupation of Territory Natural Resources Disturbance
Authorization (AOT) Authorization (AARN)
--------------------------- ---------------------------
Concession/ Legal Total Surface Surface
Parcel Status Area Activity Official N to Occupy Official N to Affect
- -----------------------------------------------------------------------------------------------------------------------------------
BRISAS Mining Title 500 Ha. Alluvial Gold
Exploitation N 42.42.43.0408 500 Ha. N 01-00-19-05-253/2004 2.16 Ha.
UNICORNIO Mining Title 500 Ha. Vein Gold,
Copper and
Molybdenum
Exploitation N 000606 500 Ha. ----- -----
BARBARA Contract
Concession 4,950 Ha. Alluvial and
Vein Gold and
Diamond
Exploration
and Exploitation N 00168 4,950 Ha. N 01-00-19-05-425/2004 568.3306 Ha.
BARBARITA Mining Title 400 Ha. Rock Aggregate
Quarry N 00168 400 Ha. N 01-00-19-05-093 14.09 Ha.
ZULEIMA Contract
Concession 844 Ha. Alluvial and
Vein Gold and
Diamond
Exploration and
Exploitation N 00170 844 Ha. N 01-00-19-05-427/2004 13.2573 Ha.
LUCIA Contract
Concession 2,525 Ha. Alluvial and
Vein Gold and
Diamond
Exploration and
Exploitation ----- ---- ----- -----
NLEAV1/
NLSAV1 Mining
Contract 58.21 Ha. Alluvial and
Vein Gold and
Diamond
Exploration,
Development and
Exploitation N 000419 52.86 Ha. N 01-00-19-05-423/2004 6,440 m2
ESPERANZA Contract
Agreement 500 Ha. Alluvial and
Vein Gold and
Diamond
Exploration,
Development and
Exploitation N 42.42.43.0681 262.71 Ha. N 01-00-19-05-482/2004 7.0211 Ha.
YUSMARI Contract
Agreement 50 Ha. Alluvial and
Vein Gold and
Diamond
Exploration,
Development and
Exploitation N 42.42.43.0681 50 Ha. N 01-00-19-05-484/2004 1.94 Ha.
EL PAUJI Exploitation
Certificate 1,850 Ha. Alluvial and
Vein Gold and
Diamond
Exploration
and Subsequent
Exploitation N 42.42.43.414 1,850 Ha. N 01-00-19-05-486/2004 3.7973 Ha.
Figure 4-1 Brisas Location Map
GRAPHIC NOT INCLUDED
Figure 4-2 Brisas Concession Map
GRAPHIC NOT INCLUDED
Early in 2004, GRI obtained lease agreements for the 500-hectare (1236
acres) Esperanza and the 50-hectare (123 acres) Yusmari properties.
Barbara is located approximately 2.6 kilometers (1.6 miles) south of
the Brisas Concession and will be the site for tailings and waste rock
disposal facilities. Esperanza, El Pauji, and Zuleima are located west
and south of the Brisas Concession and will be used for waste rock
disposal. The Yusmari property is adjacent and located on the
northeast corner of the Brisas Concession and is within the ultimate
pit boundary. The Lucia property is located 7.8 kilometers southwest
of the Brisas Concession and its use for the Project is yet to be
determined.
In 2005, GRI was granted the rights to explore and develop a rock
quarry in the 400-hectare Barbarita concession. This concession is
located totally within the Barbara property in the northeast corner.
The original Brisas alluvial concession was granted for a 20-year term
in 1988 and has two 10-year renewal periods, which may be extended at
the discretion of the MEM. The sale of gold from the alluvial
concession is subject to a three percent exploitation tax if sold
outside Venezuela and one percent tax if sold within the country to the
Central Bank of Venezuela.
The Brisas hardrock concession was granted in 1998 for a 20-year term
and also has two 10-year renewal periods, which may be extended at the
discretion of the MEM. The sale of gold from the hardrock concession
is subject to a 4 percent exploitation tax if sold outside Venezuela
and one percent tax if sold within the country to the Central Bank of
Venezuela. Copper is subject to a seven percent tax of the
"mine-mouth" value.
A new Venezuela mining law was enacted late in 1999. This law changed
the exploitation tax rates for certain minerals and metals. However,
the Brisas Concession Agreement granted by the Ministry of Energy and
Mines included a contractual agreement on exploitation taxes. The
concession agreement also pre-dates the new law. The agreement rates
have been used in the economical calculations for this feasibility
study.
As of January 2005 a new Ministry was created called the Ministry of
Basic Industries and Mining (MIBM). The new Ministry has responsibility
for all mining properties and concessions and now has jurisdiction over
CVG.
4.4 Royalties and Exploitation Taxes
- ----------------------------------------------------------------------
There are not any royalties associated with the Brisas Project;
however, the Project is subject to mining / exploitation taxes. These
taxes include the following:
One percent of the commercial value in Caracas of refined gold and
silver sold in country,
Three percent of the commercial value in Caracas of refined gold and
silver exported (saprolite concession),
Four percent of the commercial value in Caracas of refined gold and
silver exported (hardrock concession),
Seven percent mine-mouth tax on production of copper (net of operating
costs).
4.5 Environmental Liabilities
- ----------------------------------------------------------------------
The Brisas Project has areas of historical mining where timber and
vegetation have been cleared by artisan miners. Baseline (soils,
water, aquatic, and human health) surveys have been conducted over the
past ten years and continue today. Monitoring will establish the
levels, if any, of residual mercury, metals and other contaminants from
previous mining activities. The assessment and potential costs of the
existing environmental liabilities, if any, were not contained in the
Feasibility. GRI has indicated that these issues have been addressed
in the Environmental and Social Impact Assessment (ESIA) and considers
these liabilities to be minimal.
The Feasibility Study does include costs and plans for water
management, site closure, and reclamation. In addition, it includes a
plan to isolate and encapsulate any potential acid generating waste
rock. Preliminary geo-chemistry test results indicated the process
plant tailings are generally benign.
4.6 Status of Required Permits
- ----------------------------------------------------------------------
Two separate but parallel Environmental and Social Impact Assessments
(ESIAs) have been prepared for the project. The ESIAs are intended to
meet Venezuelan regulatory requirements and international financing
institutions guidelines, respectively. The objectives of the studies
are to define the project boundaries; establish environmental and
social baseline conditions; identify significant and non-significant
issues to be analyzed; develop measures that will avoid, minimize or
mitigate potential impacts; and propose monitoring programs to track
impacts. The overall objective is that the project will meet
Venezuelan regulatory requirements, as well as international
environmental and social standards including World Bank, Equator
Principles, and the International Cyanide Management Code.
The Feasibility states that the ESIAs are to provide determinations of
issues, mitigation measures, and monitoring programs. The ESIA studies
are intended to be complete, or fully define and commit to
completeness, in order to meet adequacy requirements for
international/World Bank Standards. Three Venezuelan agencies, the
Ministry of Environment and Natural Resources (MARN), the Ministry of
Basic Industries and Mining Energy and Mines (MIBM), and the
Corporacin Venezolana de Guyana (CVG) are reviewing the ESIA (which
was submitted in July 2005), permits, and authorizations for the
project.
The project is located within the Imataca Forestry Reserve. A 1996
decree zoned the reserve allowing mining within 40 percent of the
reserve area including the Brisas Project area. A 2004 decree
instituted sustainable development, multiple-use, water quality,
biodiversity, conservation, indigenous people consideration, and
environmental monitoring requirements upon development activities
within the reserve.
GRI has indicated the exploration and exploitation Authorization to
Occupy the Territory (AOT) and operating plan has been approved by MEM
for the project area. GRI has developed a project schedule and
timetable for obtaining the required permit for mining the property.
The major permit and authorizations required for the property include
the Venezuela Environment and Social Impact Assessment, Authorization
to Occupy the Territory, Authorization to Affect National Resources,
Registry of Environmental Harmful Activities, emissions, and efficient
permits.
5.0 ACCESSIBILITY, CLIMATE, PHYSIOGRAPHY, AND INFRASTRUCTURE
- ----------------------------------------------------------------------
Project accessibility, climate, physiography, and infrastructure are
addressed within this section of the report.
5.1 Access
- ----------------------------------------------------------------------
The project site is located in the Guyana region, which makes up
approximately one-third of Venezuela's national territory. The main
city is Puerto Ordaz, with approximately 700,000 inhabitants, situated
on the Orinoco River near its confluence with the Caroni River. Puerto
Ordaz has major port facilities, accessible to ocean-going vessels from
the Atlantic Ocean, via the Orinoco River, a distance of about 200 km.
Puerto Ordaz is the center of major industrial developments in the
area, including iron and steel mills, aluminum smelters, iron and
bauxite mining, and forestry. These industries are supported by major
dams and hydroelectric generating plants on the Caroni River, providing
12,900 MW of electricity (1995).
Puerto Ordaz is a modern urban center with good road and air
connections to the rest of Venezuela. There are regular scheduled
flights to Caracas and other major cities several times daily.
El Dorado, which is 88 kilometers north of the project site on Highway
10, is the nearest population center of any size. Las Claritas is a
small town located on Highway 10 near the project access road.
Highway 10 provides paved access from Puerto Ordaz, which is 373
kilometers northwest of the property, to within 3.5 kilometers of the
project site. Unpaved roads provide the remaining 3.5 kilometers of
access. Upgrading the unpaved roads is part of the infrastructure
improvement plans for the project area.
5.2 Climate
- ----------------------------------------------------------------------
The climate is tropical with high temperatures and humidity year
round. Temperatures are fairly uniform with average highs around 35
degrees C and average lows around 23 degrees C. Rainfall occurs
throughout the year with heavier amounts falling during May through
October. Total annual rainfall is 3 meters. There are extensive plans
for surface and ground water control so that mining can be conducted
year-round.
5.3 Physiography
- ----------------------------------------------------------------------
Terrain in the mine area is relatively flat with elevations ranging
from 125 to 145 meters above sea level. Near the plant site and
tailings disposal areas the terrain goes from being relatively flat to
fairly steep. The tailings disposal site design has used this as an
advantage by constructing the dam in the flat area and using the
hillside as the back of the tailings disposal facility. Elevations in
the plant and tailings disposal area range from 130 to 200 meters above
sea level. The plant site will be at 190 meters above sea level.
Most of the area is covered by moderately dense sub-Amazon
rainforest. Trees range from 25 to 35 meters in height. Low-lying
areas tend to be wet and swampy. There are a few small pits left by
artisan miners that are filled with water.
5.4 Infrastructure
- ----------------------------------------------------------------------
To support the mining and milling operations at the Brisas Project, a
number of ancillary facilities will be required. These include a mine
equipment maintenance shop, warehouse, reagent storage building,
laboratory, and administration offices. A 1,600-man construction camp
will be prepared and will be converted to a 650-man operation camp.
The operational man camp size is based on the assumption that
approximately half the work force is away on scheduled time off due to
crew rotations. Currently, there is a small camp with several cinder
block buildings that can house up to 100 people. This camp has been
used to support the exploration programs.
Two unpaved roads are used to access the project from Highway 10.
Plans are to improve these to provide access to the mining area and the
process area. A network of service roads will be constructed to allow
access to the camp facility, tailings dam, sedimentation ponds,
explosives magazine and other remote installations.
A water supply and distribution system will be constructed, using the
pit dewatering wells as a source of fresh water. The mill area, mining
area and the campsite will each be provided with a sewage collection and
treatment system.
The CVG power authority, Electrificacion del Caroni C.A. (EDELCA), has
constructed a power line south from Puerto Ordaz into Brazil. The
authority has also constructed a substation at Las Claritas which has
sufficient power to supply the Brisas Projects.
Gold Reserve's existing offices in Puerto Ordaz and Caracas will be
maintained to provide support to the operation.
6.0 HISTORY
- ----------------------------------------------------------------------
This section provides a brief history of Gold Reserve Inc. ("GRI") and
the Brisas Project.
6.1 The Company
- ----------------------------------------------------------------------
GRI is an exploration and mining company incorporated in 1998 under the
laws of the Yukon Territory of Canada. It is the successor to Gold
Reserve Corporation, a Montana USA corporation formed in 1956. GRI is
traded on the American Stock Exchange and the Toronto Stock Exchange
under the symbol "GRZ."
The Company's primary mining asset, the Brisas Project, is a
gold/copper deposit located in the Km 88 mining district of the State
of Bolivar in southeastern Venezuela. The Brisas Project consists of
the Brisas alluvial concession, the Brisas hard rock concession beneath
the alluvial concession, and applications for other mineralization
contained in these concessions, as well as contracts and concessions
for mineralization, such as gold, copper and molybdenum and
infrastructure use on land parcels contiguous to the existing
concessions. The Company holds its interest in the Brisas Project
through its ownership in Gold Reserve de Barbados, Ltd., Gold Reserve
de Venezuela, C.A. and Compania Aurifera Brisas del Cuyuni, C.A.
6.2 The Brisas Project
- ----------------------------------------------------------------------
Small miners identified gold mineralization and began working in small
pits and extracting gold from the alluvial material in the late
1970s. In 1988, a local miner acquired the mineral rights to mine the
alluvial (saprolite) ore. In the late 1980s the property was leased to
a Venezuelan company, Inversiones 871010, C.A., which constructed a
small vat leaching and process plant. The lessee had difficulty
operating the plant at a profit and stopped making the lease payments
to the owner and subsequently abandoned the property. The historical
gold production on the property is unknown.
The Brisas alluvial concession was acquired in August 1992 with the
acquisition of Compania Aurifera Brisas del Cuyuni C.A. In that same
year, Inversiones 871010, C.A. filed suit claiming ownership rights to
the Brisas alluvial concession. In December 1994, a settlement
agreement related to the ownership dispute was reached giving GRI clear
and unencumbered title to the Brisas alluvial concession. Title to the
Brisia hard rock concession was granted in March 1998.
Prior to 1992, no known drill holes existed on site. Initial work by
GRI included surface mapping, regional geophysical surveys, and
geochemical sampling. Several anomalies were identified on the
property and drilling and assaying began in 1993. The presence of a
large strata bound gold-copper mineralization was discovered in both
alluvial and hard rock material early in the drilling program.
Additional work followed with petrology, mineral studies, density test,
metallurgical sample collection and laboratory test work.
Initial exploration drilling by GRI commenced in 1993 utilizing both
auger and core drilling methods. A majority of the exploration and
development drilling took place in 1996 and 1997. From 1996 on, all
exploration drilling has been completed utilizing diamond drill core
rigs. Additional drilling was also completed in 1999, 2003, 2004 and
2005. As of April 2005, 889 holes had been drilled of which 750 are
diamond core holes. This represents 183,104 meters of core drilling,
and 199,685 total meters of drilling, core and auger. All split core
is stored on site. Since 2005, an additional 88 holes have been
drilled on the property for geotechnical and other studies. These
holes have not been included in any resource modeling because they were
not drilled for exploration purposes.
Independent verification by Behre Dolbear & Company of drilling,
assaying and data collection procedures was undertaken in 1997 and
verification of the computer database, mine modeling procedures and
reserve estimate was completed in 1998. The results of the audits
concluded that GRI procedures met or exceeded industry standards. In
addition, assay laboratories provided reliable and acceptable results.
Behre Dolbear also completed another review of an updated computer
mineralization model and a proven and probable reserve estimate in
March 1999. In September 2003, Behre Dolbear completed its own proven
and probable reserve estimate meeting the requirements of Canadian
National Instrument 43-101.
6.3 Sequence of Studies
- ----------------------------------------------------------------------
J.E. MinCorp, a division of Jacobs Engineering Group, Inc. completed a
pre-feasibility study on the Brisas Project in February 1998. In
addition, a supplement to the pre-feasibility study was completed in
August 1998, addressing the merits of the Cominco Engineering Services
Ltd. (CESL) hydro-metallurgical process. The CESL process was a method
of treating copper concentrates on site by pressure oxidation, acid
leaching with SX-EW recovery of copper in the form of copper cathode,
and gold recovery by a cyanide leach of the solids.
Work completed since 1998 and directed at project optimization includes
updating the mine computer model and ultimate pit designs, mine planning
and optimization of cutoff grades, and updated slope stability design
criteria. In addition, work was completed on mill tailings
characterization and analysis of physical properties, cyanide
destruction test, and settling and thickening tests for plant design
criteria.
GRI commenced work for a bankable feasibility study in the last quarter
of 2003. Several major engineering and consulting companies were
selected to complete the work necessary for the feasibility study.
They were Aker Kvaerner, an engineering and construction company
specializing in mining and mineral processing; Vector Colorado, a
tailings dam design, geotechnical and hydrology specialist; and Pincock
Allen & Holt for the mineral resource and reserve estimate, pit design,
mine planning and mine cost estimating. This Feasibility Study was
completed in January 2005. In addition, AATA International and
Ingenieria Caura, S.A. were selected to complete an Environmental and
Social Impact Assessment (ESIA) Study to World Bank & IFC Standards for
meeting Equator Principles criteria.
Since the Feasibility Study, several additional studies have been
completed. These include the Supplement prepared by PAH in November
2005, the Project Scope and Definition Document prepared by SNC Lavalin
in April 2006, and the Resource and Reserve Update completed by Marston
in October 2006. The combination of the Feasibility Study and these
subsequent studies provide the basis of this Technical Report.
During the first half of 2004 several optimization studies were
conducted to determine the most economic process plant option and
production rate. As a result of the studies and in combination with
the PAH mineable reserve update of July 2004, a 70,000 tonne per day
process plant was chosen. Gold will be recovered by gravity methods
from the grinding circuit, flotation of a copper concentrate, and
cyanidation of the cleaner tailings. It was also determined that the
best option for copper production would be to produce the copper
concentrate and sell it to smelter companies. Neil Seldon &
Associates, Ltd. was selected to determine the best options for selling
the copper concentrate, the estimated terms for treatment cost and
payable metals, and to initiate future negotiations with smelter
companies.
Approximately $70 million has been spent on the development of the
Brisas Project. It includes the acquisition, exploration and
development drilling, assaying, metallurgical test work, field
geo-technical work, a pre-Feasibility Study, feasibility study,
detailed design, and environmental studies.
7.0 GEOLOGIC SETTING
- ----------------------------------------------------------------------
7.1 Project Geology
- ----------------------------------------------------------------------
The Brisas Project is within the Guayana Shield in northern South
America. The shield covers easternmost Colombia, southeastern
Venezuela, Guyana, Suriname, French Guiana and northeastern Brazil.
The Venezuelan portion of the shield is subdivided into five geological
provinces with different petrological, structural and metallogenic
characteristics. The provinces are, from oldest to youngest, Imataca,
Pastora, Cuchivero, Roraima, and Parguaza. Only Imataca, Pastora and
Roraima provinces are found in the vicinity of the Brisas deposit and
will be described briefly.
Rocks of the Imataca province constitute the oldest terrain in the
Venezuelan Guayana Shield and include quartzo-feldspathic gneiss,
felsic and mafic granulites, and iron formation. This province is
located along the Orinoco River in the northern portion of the Guayana
Shield. Rocks in the terrain are tightly folded, highly metamorphosed,
and have ages ranging from 3700 Ma to 2150 Ma. The oldest age
represents the protolith, whereas the younger age represents the
Trans-Amazonian orogeny of Lower Proterozoic age. The Imataca Province
is known for iron deposits hosted by banded iron formations.
The Pastora Province is separated from the Imataca terrain by the Guri
fault on its northern edge and extends to the Km 88 gold district in
the south. This province is characterized by several
penecontemporaneous tholeiitic and calc-alkaline volcano-sedimentary
sequences. Rock types that have been described and not necessarily
present in all sequences include pillow basalt, andesite, dacite,
rhyolite, tuffaceous and pyroclastic sediments, graywacke, pelite,
tuff, and chemical sedimentary rocks. Rocks of the province were
metamorphosed to greenschist facies and intruded at various levels by
granitic rocks of the Supamo Complex (2230 - 2050 Ma). This petrologic
assemblage constitutes the granite-greenstone belts of Lower Proterozoic
age, which extends into Guyana, Suriname, French Guiana, and Brazil.
The Trans-Amazonian orogeny (2150 - 1960 Ma) was a period of
deformation, metamorphism, magnetism, and enrichment of previously
deposited gold-bearing volcano-sedimentary rocks in the Venezuelan part
of the Guayana Shield as well and in the other mentioned countries.
Rocks of this province have been intruded by Lower Proterozoic (1850 -
1650 Ma) and Mesozoic (210 - 200 Ma) diabase dikes, sills, and gabbroic
bodies related to crustal extension.
The Roraima Province of Middle Proterozoic age (1600 Ma) is exposed to
the south of the Km 88 district. This province includes sedimentary
rocks of continental origin that were laid uncomformably on top of the
granite-greenstone terrain. These rocks are not metamorphosed, have
horizontal to low angle dips and are intruded by Mesozoic diabase dikes
and sills.
7.1.1 District Geology
- ----------------------------------------------------------------------
The Km 88 district lies wholly within the lower Proterozoic greenstone
terrain of the Pastora Province. It is bordered to the south by a
1,000-meter vertical escarpment of the Roraima Province sedimentary
sequence.
7.1.2 Sequence of Units
- ----------------------------------------------------------------------
The greenstone belt present in the Km 88 district (Figure 7-1) consists
of four formations, listed below oldest to youngest:
1) Lower Carichapo Group meta-lavas, meta-tuffs, amphibolites, and
ferruginous quartzites.
2) Lower Proterozoic greenstone basalts, andesites, tuffaceous rocks,
pyroclastic breccias, and metagraywackes. These rocks are
lithologically similar to the Caballape Formation defined in the
Botanamo district to the north east, but geographically isolated. For
convenience, they are referred to as Lower Caballape in this report.
3) Granites and granodiorites of the Supamo Complex.
4) Diabasic and gabbroic dikes and sills of Lower Proterozoic and
Mesozoic ages.
The position and coverage of the above units have been established, at
least on a regional scale, through aerial photos. Ground
reconnaissance by government missions and more recently by private
entities has either confirmed or mapped modifications to the aerial
interpretations. The present geologic map is a composite of the above
work. Rocks of the Carichapo Formation surround the Brisas Concession
to the southwest, southeast, east, and north. They generally
correspond to areas of higher topographic expression and are not
commonly host to significant gold deposits. Greenschist volcanic and
volcano-sedimentary rocks of calc-alkaline composition (called Lower
Caballape Formation in this report) constitute the major units present
in the areas of gold deposits, including the Brisas and Las Cristinas
properties. On Figure 7-1 they have been divided into two units. The
older unit covering the Brisas Concession consists primarily of
intermediate tuffaceous rocks, and the younger unit to the west
consists of intermediate to felsic tuffs, lavas, and
volcano-sedimentary rocks. This sequence of rock units corresponds to
areas of low, flat topography, forming hills only where the rock mass
is more silicified. Relatively unfoliated intrusions of Supamo Complex
granites are restricted to the south, east, and northeast, where they
are topographically indistinct from the greenschist volcanics. All of
the above units are intruded by Lower Proterozoic and Mesozoic diabases
and gabbroic bodies, both as large mapable features, and as thin dikes
and sills occurring in the volcanic units.
7.2 District Structure
- ----------------------------------------------------------------------
Structure of the Pastora-Supamo terrain at the regional level is poorly
understood, partly due to a thick weathered horizon and dense
vegetation. Integration of mapping data at a scale of 1:5000 with
interpretation of remote sensing data at a 1:250,000 scale indicates
that two major structural domains affect the Km 88 district.
Side Looking Radar imagery shows linear features that strike N30W.
Ground reconnaissance and drilling on the Brisas Project confirms that
these linear features are related to small-scale joint and fracture
sets, and large scale faults.
FIGURE 7-1 GEOLOGICAL MAP OF KM 88 DISTRICT
GRAPHIC NOT INCLUDED
Some of these features have been intruded by diabase dikes. In
addition, zones of quartz veining, some of which are associated with
gold mineralization, have a N30W orientation.
Mapping of road cuts, mining pits, and rock exposures in the Km 88 area
show a pervasive foliation orientation of NS to N25E, averaging N10E,
and dipping 30 to 55 degrees NW. This information is restricted to
areas where small mining has exposed rock with visible structure. To
the north of the Brisas Project, the possible existence of a large fold
in the volcanic strata has been reported, swinging the orientation to
N30W. This change is coincident with a large mafic dike that strikes
N45E, the only large feature of this orientation in the district. At
the southern boundary of the Brisas Project and to the southwest,
strikes swing to a N30W orientation.
7.2.1 Site Geology
- ----------------------------------------------------------------------
The Brisas Project includes the Brisas property, and the properties of
La Esperanza, Yusmari, El Pauji (composed of six adjacent lots),
Zuleima, Barbara, and Barbarita (see Figure 3-1). This section will
first focus on the project site as a whole, then on the Brisas property
itself and the contained gold/copper deposit in greater detail.
Rocks from the Carichapo Formation, younger greenschist volcanics,
Supamo Complex, and later diabase and gabbroic bodies occur within the
boundary of the Brisas Project.
The lower Carichapo rocks occur primarily in eastern Barbara and
Barbarita properties, and touch the southeast corner of the Brisas
property. Locally they consist of (1) well-foliated volcanic
tuffaceous rocks, mafic flow units, and (2) amphibolites. They are
distinct from the gold-bearing greenschist volcanics in that
recognizable primary textures are absent.
Lower Caballape Formation greenschist tuffaceous and
volcano-sedimentary rocks cover the majority of the Brisas property, La
Esperanza, and the northern part of El Pauji. Foliation orientations
vary, with a strong N10E strike in the Brisas property to NS and N30W
in La Esperanza and El Pauji. Primary textures are readily visible in
fresh exposures of this formation.
Granites of the Supamo Complex occur throughout much of the Barbara and
Zuleima properties, and show little to no foliation. There has been no
direct evidence of the contact between this unit and the metamorphosed
volcanics. In other parts of the Pastora Province, this lack of
contact information has proved problematic in determining age
relationships between the granites and the volcanics (such as the Lower
Caballape Formation). It is assumed, in the Km 88 district, that Supamo
granites post-date the extrusive volcanic formations.
Younger, relatively unweathered and unfoliated diabase and gabbro
bodies occur scattered throughout the Brisas Project. The most
significant occurrence of diabase rock is a large dike with a curving
NS strike (convex to the west) that forms the ridge in Barbarita. This
unit interfingers on a fine scale with amphibolites and lesser gabbroic
bodies and exhibits a low degree of surficial weathering. Thin mafic
dikes also occur throughout the Brisas, Barbara, and El Pauji
properties, all subvertical with a N30W strike. Several elliptical
gabbro bodies exist in the Lucia property, and a larger gabbro body is
thought to exist in the southwest of the Barbara property.
7.3 Detailed Geology of the Brisas Project
- ----------------------------------------------------------------------
The Brisas Concession itself lies within a portion of the lower
Caballape Formation volcanic and volcanic-related sedimentary rocks
(Figure 7-2). The units present are (1) andesitic to rhyolitic
tuffaceous volcanic beds, (2) related sedimentary beds, and (3) a
tonalitic intrusive body. All rocks have been tilted and subjected to
lower greenschist facies metamorphism. It is thought, based on
information from nearby properties, that the Brisas Project occupies
one limb of a large regional fold. Limited direction-indicating
structures show the strata to be top-up. In the main mineralized
trend, moderate to strong foliation is oriented N10E and dipping 30 to
55 degrees NW. This foliation appears to be parallel to the original
bedding and tends to be strongest in the finer-grained rocks. A much
weaker foliation orientation appears in outcrop exposures, striking
north-northwest and dipping to the southwest.
Dikes and quartz veins cut the lower Caballape Formation. The strata
and intrusive rocks are cut by N30W striking mafic dikes emplaced at
regular intervals (200-600 meters), some of which have displacement on
the order of tens of meters. These dikes are thought to be related to
the Mesozoic diabase intrusions present throughout the district.
Quartz veins populate the Concession and have been noted both in
outcrop and in drill intersection. The most common are sets of thick,
boudinaged, and en echelon vein structures that follow
foliation/bedding orientation. They are thought to relate in part to
movement of quartz during metamorphism. Other quartz veins exist in
various orientations that cannot be definitively linked to the
structural elements described above.
7.3.1 Rock Units
- ----------------------------------------------------------------------
There are two general categories of rock units: weathered and
unweathered rock. Weathered rock is further defined by degree of
oxidation and mineral replacement due to weathering processes (see
Figure 7-3). Unweathered rock is further defined by lithology into
various subdivisions of volcanic extrusive or intrusive units.
7.3.2 Weathered Rock and Saprolite
- ----------------------------------------------------------------------
Oxidized Saprolite. A red-brown to yellow saprolite occurs in almost
all parts of the concession from the surface to an average depth of 24
meters. It is absent in the few areas where hard rock material
outcrops. It is composed of clays, quartz, and hard ferruginous
material in which all sulfide minerals have been oxidized and most
other rock-forming minerals have been broken down to clay minerals and
quartz.
Sulfide Saprolite. Sulfide saprolite, varying in thickness from less
than 1 meter to 80 meters, occurs immediately below oxidized
saprolite. The water table constitutes the contact between the two and
is generally sharp. It is noted on the geologic logs as BOS (base of
oxidized saprolite). Sulfide saprolite is predominantly clay with both
primary and secondary sulfides, the original rock having been broken down
Figure 7-2. SURFACE GEOLOGY OF THE BRISAS PROPERTY (SAPROLITE REMOVED)
GRAPHIC NOT INCLUDED
Figure 7-3. TYPICAL WEATHERING COLUMN FOR THE VOLCANIC ROCKS OF THE
BRISAS PROPERTY
GRAPHIC NOT INCLUDED
beyond recognition. Fragments of hard tuffaceous rock can occur. The
initial occurrence of hard rock fragments in this unit (or in oxidized
saprolite) is denoted on the geologic logs by the acronym BAS (base
of 100 percent clay material). This boundary can exist in either
sulfide or oxidized saprolite. The sulfide saprolite is well developed
in the mineralized zone of the concession, but can be quite thin or
absent in areas distal to mineralization.
Weathered Rock. Weathered rock is a label for any hard rock existing
in a state of intense weathering, but not sufficiently broken down into
clay to qualify as a saprolite. In general it falls between two
contacts noted on geologic logs as BZM (base of mixed clay/hard rock
material) and BDM (base of weathering). In practice it is logged as
the original rock type or as schist in the event that the original
texture cannot be distinguished. Below the BDM, rock exists in a state
of weathering in which the only chemical change is the leaching of
calcite. The base of this layer is denoted as BDL (base of
leaching), below which the rock is considered completely fresh.
7.3.3 Unweathered Rock
- ----------------------------------------------------------------------
Schist Units. The classification of schist is used when the original
tuffaceous texture of the rock units has been erased by metamorphic
processes. Schistosity is developed parallel to bedding, so schist
units generally, but not always, follow dip of the tuffaceous units.
Two types of schist have been defined: chlorite-sericite-biotite
schist and quartz-sericite-pyrite schist.
Volcanic Units. The original unweathered rock types are calc-alkaline
volcanic tuffs, generally of andesitic to dacitic composition.
Occurrences of tuffaceous units reworked by sedimentary processes have
been noted, but not to any great extent. Nomenclature of tuffaceous
units has been established through observation of core, petrographic
analysis, and geochemical data. Bedding and, to a lesser extent,
graded bedding are commonly recognized. In general, feldspar crystal
abundances are counted only with crystals exceeding 1 mm in diameter,
and the field term of a lapilli is a pyroclast exceeding 2 mm in
diameter. The following ternary diagram (Figure 7-4) illustrates the
composition of the various volcanic rock types recognized on the
Concession.
a) Vitric Tuff. Vitric tuff (TV) is a fine-grained, crystal-poor
tuffaceous volcanic rock usually black in color where not highly
sericitized. It consists predominantly of glassy material, now
devitrified, from the fallout of ash-sized particles. By definition it
contains less than 10 percent feldspar crystals and less than 10 percent
lithic fragments. It varies from a finely-banded volcanic sediment, to
more massive mud-flow type deposit which may contain lapilli
pyroclasts, to a fine-grained massive texture. It is fully gradational
into TVC-M and TL units (defined later).
b) Crystal-Vitric Tuff. Crystal-vitric tuff (TVC-M) is defined as a
tuffaceous unit having 10 percent to 40 percent feldspar crystals, and
less than 10 percent lithic fragments. Locally the crystal content can
drop as low as 10 percent but averaged over an entire depositional unit
must exceed 10 percent. The upper boundary of 40 percent crystals is
arbitrarily set, local fluctuations being ignored. When lapilli are
observed and amount to more than a few percent of the rock mass, the
unit is described as a lapilli-bearing TVC-M or TV.
FIGURE 7-4. Gold Reserve Inc.
Brisas Project, Venezuela
Feasibility Update
Ternary Diagram for Classification of Tuffaceous Units
Each corner represents a rock consisting entirely of the
component listed
DIAGRAM NOT INCLUDED
c) Crowded-Crystal-Vitric Tuff. Crowded-crystal-vitric tuff (TVC-C)
is defined as a tuffaceous unit having greater than 40 percent feldspar
crystals and less than 10 percent lithic fragments. It commonly
contains significant mafic minerals (e.g., amphibole altered to
biotite). If more than a few percent lithic fragments are observed,
the unit is described as a lapilli-bearing TVC-C.
Crowded-crystal-vitric tuff commonly resembles andesite porphyry, but
numerous small lithic lapilli and grain size variations refute this
possibility.
d) Lithic Tuff. Lithic tuff (TL) is defined as a tuffaceous unit
containing greater than 10 percent lapilli-sized fragments. This
definition is used without regard to presence or absence of feldspar
crystals in the matrix, as field rock descriptions do not allow for
further textural distinction. The fragments in some cases appear to be
pieces of tuffaceous rock, presumably torn from its location by later
volcanic activity. Pumice fragments have also been noted. It has been
found to be important as a marker horizon, as it has an unmistakable
texture and for the most part is observed in thin but easily definable
units.
Intrusive Units. There are three mineralogically and texturally
distinct occurrences of intrusive units, which vary from basaltic to
dioritic in composition, all of which are younger than the tuffaceous
units described above.
a) Mafic Dikes. This fine-grained, probably hypabyssal rock has a
prominent spinifex texture defined not by olivine, but rather by
feldspar grains. They are unaltered, unfoliated, and magnetic. There
are six such dikes on the concession, striking generally N40W, spaced
200-600 meters apart. They range from less than 1 meter to over 5
meters in width. Cross-cutting relationships indicate that they are
the youngest rocks on the Concession.
b) Intermediate Coarse-Grained Intrusive. A coarse-grained tonalitic
intrusive has been identified in only one area in the eastern part of
the Concession. It appears to be amorphous in shape and drilling has
not encountered a lower contact. It is a coarse-grained, equigranular
rock in large part unfoliated, but cut by discrete zones of strong
deformation, both with and without sulfides and alteration. Zones of
fracture-controlled chalcopyrite are also present, though the body does
not exhibit economic Au or Cu mineralization. The only contacts
observed to date are with TVC-C and are difficult to pinpoint as the
two units can appear similar in hand sample. In one drill hole, it is
cut by a mafic dike. The equigranular texture, high quartz content,
and grain size are diagnostic. TVC-C, with which it is sometimes
confused, tends to have much greater variation in crystal content.
c) Intermediate Aphanitic Sill/Dike. Intermediate hypabyssal
intrusives occur as sill-like bodies less than 1 meter thick. These
intrusives are usually aphanitic and are weakly foliated. They are
useful as marker horizons within the volcaniclastic pile.
7.3.4 Stratigraphy
- ----------------------------------------------------------------------
A stratigraphic column for the concession has been defined (Figure 7-5)
from the lithologic interpretation of over 800 drill holes and is
presented below in outline form (oldest to youngest):
A) The lowest grouping is a sequence of crystal and crowded-crystal
tuffaceous units that have a uniform appearance with very gradual
changes in crystal percentages. The base of this sequence has not been
reached by drilling.
B) A thick crystal-vitric tuff and underlying vitric tuff that appears
only in the northern part of the Concession (north of 682,500 N).
South of this line the unit either pinches out, or drilling has been
insufficient at depth to properly define it.
C) A 150-200 meters thick sequence consists of rapidly alternating TL,
TV, and TVC-M units. A prominent band of TL defines the base. Within
this group only the TL bands and one TV bed are found to be laterally
continuous, though even they are highly variable in thickness and
extent. The bulk of economic Au mineralization occurs within this
sequence. A sill of intermediate composition exists near the base of
this sequence and is traceable throughout the concession. The entire
sequence thins toward the south, narrowing to less than 100 meters at
681,500 N.
D) A TV unit greater than 200 meters thick appears throughout the
concession and contains minor TVC-M and TL bands. Much of this unit
has a very even texture, and the contact with the underlying unit is
readily apparent in most drill holes.
Figure 7-5. VOLCANIC STRATIGRAPHIC COLUMN OF THE BRISAS PROPERTY.
GRAPHIC NOT INCLUDED
E) A poorly defined sequence of TL, TV, TVC-M, and TVC-C units overlies
(D), but is well outside, the mineralized zone and only encountered in a
few condemnation drill holes to the west. This area has a strongly
developed foliation, to the point where many units have been lumped
together as schist.
F) A diorite/tonalite intrusive feature exists on the eastern edge of
the Concession that appears to postdate emplacement of the tuffaceous
units, as it cross-cuts the stratigraphy. However, information about
the contact between this body and the tuffaceous units is limited. No
strong mineralization has been discovered in or at the margins of this
body.
8.0 DEPOSIT TYPES
- ----------------------------------------------------------------------
There are four distinct types of Au and Cu mineralization present in
the concession, defined by geometry, associated minerals, and the Au/Cu
ratio. These zones are the Blue Whale body, disseminated
gold+pyrite+/-Cu, disseminated high Cu, and shear-hosted Au. Only the
first three types are encountered within the proposed pit geometry. A
more detailed description of the mineralization follows in Section 9.0
of this report.
9.0 MINERALIZATION
- ----------------------------------------------------------------------
9.1 Types
- ----------------------------------------------------------------------
There are four distinct types of Au and Cu mineralization present in
the concession, defined by geometry, associated minerals, and the Au/Cu
ratio. These zones are the Blue Whale body,
disseminated gold+pyrite+/-Cu, disseminated high Cu, and shear-hosted
Au.
9.1.1 The Blue Whale Body
- ----------------------------------------------------------------------
The Blue Whale mineralized body is a discrete, sharply bounded,
flattened, cigar-shaped feature that trends more or less parallel to
the local schistosity and plunges about 35 degrees SW along foliation.
It outcrops in the Pozo Azul pit in the NE portion of the Concession,
and is intersected by 45 drill holes. It is 20 meters in diameter at
its widest point, and tapers off at depth. It is volumetrically a small
fraction of the economically mineralized ground at the Brisas Project,
but it possesses the highest Au and Cu grades.
Mineralogically, the Blue Whale is a
sericite-tourmaline-pyrite-chalcopyrite-quartz schist, with a smaller
volume of quartz-tourmaline-sulfide breccia. The schist is
fine-grained and exhibits an almost complete alteration of the original
rock. What appears to have been feldspar crystals and lapilli fragments
are now replaced by tourmaline, and in some cases tourmaline bands occur
in multiple deformed sheath fold structures. It is unclear whether the
tourmaline itself has undergone this deformation, or if it has replaced
minerals in a preexisting structure. Thin quartz veins that cut the
schist also show varying degrees of deformation, both brittle and
ductile. Gold and Cu grades are highly variable in the schist,
normally increasing toward the contacts between the schist and the
breccia. Pyrite/chalcopyrite is up to 25 percent of the rock mass,
with abundant chalcopyrite and molybdenite.
The quartz-tourmaline breccia portion of the Blue Whale exhibits the
highest Au and Cu grades of the Brisas Project. Tourmaline has
completely replaced blocks of the breccia, while quartz has flooded the
matrix. This rock does not show the strong ductile deformation of the
sericite-pyrite-quartz schist. Chalcopyrite is the dominant sulfide,
with lesser pyrite, bornite, covellite, and molybdenite. Other
alteration minerals present are sericite, rutile, calcite, albite,
siderite, and minor anhydrite (the latter occurring in undeformed,
crosscutting veinlets).
9.1.2 Disseminated Au+pyrite+/-Cu
- ----------------------------------------------------------------------
The bulk of ore mineralization occurs in disseminated, coalescing,
lensoid bodies, high in Au and in most cases low in Cu. These bodies
lie almost exclusively in the lapilli-rich, rapidly alternating
sequence of tuffaceous units described in part (C) of the stratigraphy
(see Figure 9-1), and are clearly aligned along foliation. Together,
these lenses form a generally well defined mineralized band which
mimics the dip of the foliation/bedding and remains open at depth. It
remains at a similar thickness from the northern concession boundary
for a distance of 1.4 km south, after which it tapers rapidly.
Alteration minerals characteristic of these lenses are epidote,
chlorite, secondary biotite, and sericite.
The Au in the stratiform lenses is highly disseminated but only roughly
associated with high occurrences of pyrite. Fine-scale sub-sampling of
three meter assay intervals indicates good correlation between Au and
small (<1 cm) calcite/quartz veins. Correlation also exists with zones
of high occurrence of epidote, and in lapilli-sized lithic fragments
that have been partially to completely replaced by epidote and
sulfides. Sub-sampling evidence also suggests that Au is more evenly
distributed through the rock near the center of the large mineralized
lenses than it is near the margins. In section, east-west contours of
gold grades at 0.75 or 1.0 g/t show a geometry that essentially mimics
contours drawn at 0.40 g/t.
9.1.3 Disseminated High Cu/Low Au
- ----------------------------------------------------------------------
Stratiform lenses of high Cu (with or without high Au) parallel and
underlie the Au+pyrite lenses described above. These lenses outcrop in
the northern part of the deposit, and plunge to the south along the
bedding/foliation in a manner similar to the Blue Whale and high Au/low
Cu lenses. Deep drilling has intersected these lenses as far south as
681,900N. Within the stratigraphic column, these lenses generally
occupy the TV and TVC-M units described as sequence (B) of the
stratigraphy (Figure 9-1). Rock in the mineralized zones is
characterized by a high degree of lapilli and crystal replacement by
chalcopyrite, and in some cases, by bornite and covellite. High
chalcopyrite in the rock matrix is often accompanied by high chlorite,
secondary biotite, and in some cases molybdenite.
9.1.4 Au-bearing Shear Zones
- ----------------------------------------------------------------------
Shear-hosted gold occurrences exist in the southern part of the
concession, running parallel to the foliation as with mineralization
further north. Stratigraphically, they occur above the large
disseminated lenses previously described. The gold grades are erratic
and localized, up to 100 g/t Au over a three-meter core interval.
There is a high degree of correlation between chalcopyrite and Au
grade, though Cu grades in these shears is sub-economic.
9.1.5 Alteration
- ----------------------------------------------------------------------
Alteration of the original rock-forming minerals, such as amphibole and
feldspar, and addition of elements such as boron and sulfur, is a result
of hydrothermal, metamorphic, and weathering processes. The
overprinting of these three processes has created a number of
gradational alteration assemblages, which include varying amounts of
quartz, secondary biotite, chlorite, sericite, calcite, epidote,
metallic sulfides, tourmaline, magnetite, and minor fuchsite and
anhydrite.
Hydrothermal alteration is most intense within the Blue Whale body, and
in other isolated pockets of similar appearance scattered throughout the
main mineralized trend. The alteration type of the breccia approaches a
greissen, with components of phyllic alteration in the schist. In many
cases within the breccia pipe, fragments have been completely replaced
by tourmaline, and associated zones of quartz may be a result of
tourmalinitization of feldspars. Petrographic analysis shows two
separate phases of growth in some tourmaline crystals. Massive
occurrences of sulfides typically show an earlier phase of pyrite
formation with subsequent fracturing and infilling of fractures by
chalcopyrite.
Figure 9-1 E-W SECTION AT 683000N LITHOLOGIC WITH Au AND Cu MINERALIZED
Weaker propylitic alteration is present in tuffaceous units surrounding
the Blue Whale body as strong calcite+epidote+pyrite and
calcite+chlorite+pyrite+epidote+chalcopyrite assemblages. Typically,
in lenses of high Cu/low Au mineralization, the alteration package is
more potassic (high secondary biotite+chlorite+-sericite). Many veins
with these alteration assemblages are highly deformed, indicating
emplacement prior to metamorphism.
Metamorphic alteration occurs throughout the concession and is thought
to be the result of regional burial. Petrographic analysis identifies
both biotite grade and chlorite grade metamorphic facies, occurring in
the lower mesozone and upper epizone, respectively. This corresponds to
a temperature range of 300 to 500 degrees C, and hydrostatic pressures.
The Au+pyrite+/-Cu disseminated lenses appear to be associated with
fluids present during this metamorphic event. The primary orientation
of schistosity is thought to be parallel to bedding, with a weakly
developed secondary schistosity at about 10 degrees to bedding. Some
chlorite and epidote formation may be attributed to subsequent
retrograde metamorphism. Overprinting this initial metamorphism is an
alteration assemblage possibly related to a tensional event that
resulted in the development of barren calcite+/-quartz veins.
Weathering has resulted in the breakdown of the above mineral
assemblages according to their compositions, ultimately resulting in
the formation of smectite, illite, and kaolinite. Pyrite is retained
in the unoxidized material, though is typically very fine grained and
sub- to euhedral, suggesting secondary formation. Chalcocite is
present in areas of high copper. Above the water table iron oxides
have formed after sulfide minerals, releasing free gold. The
assemblage most resistant to this process is the Blue Whale breccia,
due to the high silica and tourmaline content.
9.1.6 Trace Element Geochemistry
- ----------------------------------------------------------------------
A total of 55 samples were chosen for geochemical analysis of trace
elements, and of this number, 28 were analyzed for major rock-forming
elements. Samples were chosen to provide a range of rock types and a
range of locations relative to the mineralized trend. Results indicate
some trends both on a concession-wide scale and also within the Blue
Whale body. 'Anomalous' levels of trace elements are determined by
comparing the values to established background levels for similar rock
types.
The mineralized trend is defined by anomalous Au, Cu, Mo, Ag, and W.
Anomalous Cr exists in all parts of the Concession, but does not target
the main mineralized trend. The Blue Whale body is characterized by
higher levels of Mo, Ag, Sn, W, Cd, and Hg, though not all these
elements occur in anomalous concentrations. Cu and Ag increase down
plunge within the Blue Whale body, while W, Mo, and Hg decrease down
plunge. A clear constant proportionality exists between the elements
Cu and Ag in all samples.
Background levels of Sb and As occur over the majority of mineralized
zone. They rise to anomalous levels (>1 ppm Sb and >2 ppm As) in the
southern part of the main mineralized trend, and continue to be
anomalous to the southern concession boundary.
Plotting immobile elements on a SiO2 vs. Zr/TiO2 diagram indicates an
original andesitic composition for the volcaniclastic rocks with very
little compositional spread. The mafic dikes plot as sub-alkaline
basalts. The coarse-grained intrusive plots as quartz diorite, a
classification that is compositionally analogous to the tuffaceous
units.
Major element percentages (analyzed as oxides) do not indicate any
clear enrichment or depletion in relation to the mineralized zone.
These elements were not used for rock classification as original
compositions have undoubtedly been changed due to metamorphism and
hydrothermal alteration.
9.2 Geological Model
- ----------------------------------------------------------------------
Surface mapping and evidence gathered from logging of drill core yields
a rough model for the formation of the host rocks and Au/Cu mineralized
body on the Brisas Concession. Below, in outline form, is a chronology
of possible events leading to present day.
I - Initially, there was deposition of tuffaceous units during the
Lower Proterozoic in a shallow marine to sub-aerial environment.
II - Regional compression caused closure of the shallow basin, folding
the tuffaceous units on a large scale. On the Brisas Concession, this
activity manifested itself in tilting the strata (the fold axis is not
observed on the Concession).
III Burial of volcanic package. During this time the rocks may have
been metamorphosed to greenschist facies.
IV - Occurrence of high temperature hydrothermal activity rich in
Au+Cu+Mo associated with the Blue Whale and some of the disseminated
lenses. Blue Whale probably constituted the primary tensional feature
acting as fluid conduit.
V Partial erosion of overlying material and occurrence of another
phase of mineralization, which was lower temperature, Au-rich, and
Cu-poor. Mineralization occurred in a relatively tight structure,
causing broad lenses of disseminated ore rather than more concentrated
vein or shear-related Au enrichment.
VI - Later influx of hydrothermal fluids yielding barren quartz/calcite
veins.
VII - Fractures developed in a NW-SE orientation during a phase of
crustal extension (Transamazonian), and one of these fractures appears
to have formed preferentially along the plane of weakness associated
with the Blue Whale.
VIII - The NW-SE fractures were filled by mafic intrusive material in
the Late Proterozoic to Mesozoic.
IX - Erosion of overlying material exposed both the Blue Whale body and
the disseminated mineralized lenses. Development of a pronounced
weathering profile.
9.2.1 Genesis of Deposit
- ----------------------------------------------------------------------
There appear to be two phases of Au and/or Cu mineralization on the
concession. The first is associated with the emplacement of the Blue
Whale breccia body, and the second with the large Au-rich disseminated
lenses parallel to bedding of tuffaceous units. The following is a
hypothesis of the structural and mineralogical event that led to
deposit formation.
Stage 1 (Blue Whale breccia, step IV listed above)
The balance of evidence suggests that the Blue Whale body is a purely
structural feature. It is a dilational zone of weakness that has
acted, at some point after deposition of the tuffaceous rocks, as a
conduit for mineralizing fluids. Based on structures seen within the
Blue Whale, this occurred before or during regional metamorphism. The
initial pulse of mineralization probably occurred when the system was
relatively young. Brecciation, on a limited scale, took place along a
preexisting fracture with fluids rich in B, Cu, Au, and lesser Mo.
Alteration in and directly around this feature was intense, causing
complete replacement of breccia fragments by tourmaline, massive
quartz, and copper that roughly targets the Blue Whale in plan view. A
possible deposit analogy is of a copper porphyry forming over a magmatic
source (yet to be discovered) that was very rich in boron. A
peraluminous granite might fit the boron requirements, and a sufficient
volume of basaltic/andesitic rock could provide the copper. Thin lenses
of high Cu and Mo extending away along bedding/foliation planes could be
the result of periodic high confining pressures within the Blue Whale
that forced mineralizing fluids outward along these planes. The fluids
replaced crystals and lithic fragments, evidence of which can be viewed
in drill core.
Stage 2 (disseminated Au lenses, step V listed above)
The bulk of Au mineralization at the Brisas deposit appears to have
been emplaced after formation of the Blue Whale mineralization. It
occurs over a wide area and the highest Au grades do not occur in
proximity to the Blue Whale. Although on a small scale Au appears to
link with zones of higher schistosity and development of alteration
minerals, on a larger scale it appear that this fluid phase targeted
the distinctive lithologic zone of thin, variable tuffaceous rocks
described in Part C of stratigraphy. The bedding discontinuities and
relatively porous lithic fragments of this zone may therefore be the
overriding factor in mineralization. The fluid pressures must have
been high to disseminate them through an unfractured volcanic pile
rather than along obvious shear planes or fractures.
Mineralogically, this phase of deposition bears some similarity to the
high temperature B, Cu, Au, and Mo fluid phase proposed for the Blue
Whale, specifically in regards to the formation of disseminated
lenses. Geometrically, this package of lenses plunges to the south,
where it can still be detected by deep drilling. This pattern is
similar to what is observed in the Blue Whale.
9.2.2 Later Remobilization
- ----------------------------------------------------------------------
Remobilization may have affected the distribution of Au at later times,
and one example of this is the Au occurrences at the edges of quartz
veins and shears in the south part of the concession. Quartz veins
with edges exhibiting high concentrations of Cu-sulfides exist in the
northern part of the property. In addition, metamorphism may have
occurred more than once, each time changing slightly the distribution
of Au and Cu. However, these effects are probably not substantial, as
the planar geometry of the Au mineralization still exists in the
disseminated lenses and the sharp jump in Au and Cu grades still
closely define the boundaries of the Blue Whale body.
10.0 PROJECT EXPLORATION
- ----------------------------------------------------------------------
GRI began exploration on the Brisas Project in late 1992 after its
acquisition of the property. Prior to 1992, no known drill holes
existed on the property. Local miners working in small pits dug in the
alluvial material had identified gold mineralization. Initial work by
GRI included surface mapping, regional geophysical surveys, and
geochemical sampling. Several anomalies were identified on the
property followed by drilling and assaying starting in 1993. The
presence of large quantities of stratabound gold and copper
mineralization was identified in both saprolite and hard rock material
early in the drilling program. Additional work followed with
petrology, mineral studies, density tests, metallurgical sample
collection and laboratory test work. Several drilling campaigns have
taken place at the Brisas Project and continue to present times.
10.1 Exploration Model
- ----------------------------------------------------------------------
Emphasis of exploration on the concession focuses on following the
mineralized lenses downdip to the west and down plunge to the south.
Drilling originally concentrated at the surficial exposure of the Blue
Whale, and continued to the west and south where the mineralized lenses
were found to extend at depth. The convention of drilling at an
inclination of 60 degrees and at a bearing of N 90 degrees E was
established once it became known that the mineralized lenses closely
followed the dip of bedding/foliation, and that this drilling
orientation was perpendicular to both. Occasional drill holes are
placed underneath areas of intense working by small-scale miners to
test the extent of additional gold occurrences.
Geochemical sampling on the surface follows a program of total coverage
of the concession area, along with a widely spaced drilling grid of
holes to depths of at least 200 meters. Any suspected gold targets
found by these methods are followed up by additional surface sampling
or drilling.
11.0 PROJECT DRILLING
- ----------------------------------------------------------------------
GRI began exploration activity in late 1992 and continued various
drilling programs through the present time. A total of 977 drill holes
with a total drilled length of 207,751 meters have been completed by GRI
at Brisas as of September 2006. Of these holes, 802 representing
189,985 meters of drilling were drilled specifically for exploration on
the Brisas Concession. The remaining holes were drilled for hydrologic,
geotechnical, and metallurgical testing. In some cases the test holes
were assayed and used in modeling.
Drill hole spacing within and around the planned pit area is about 50
meters or less. Drill hole spacing in the disseminated high Cu/low Au
and Blue Whale areas is about 25 meters. The majority of the
exploration drilling was performed using standard diamond core-barrel
recovery techniques although some auger drilling was carried out at the
beginning of the exploration campaign. Auger holes ("A" holes) are
generally very shallow, and are scattered throughout the project area
and in between later-drilled core holes; many auger holes are outside
the pit area. Also, about half of the auger holes were deepened using
regular core hole drilling techniques ("AD" holes). Auger holes were
included in the resource estimation process.
The resource/reserve estimate presented in this report includes
drilling results up to hole D845 drilled in March 2005. A summary of
drilling at the Brisas Project from 1993 through 2006 is shown in Table
11-1. The drilling also included drill holes for metallurgical,
geotechnical, hydrological testing, and independent verification. A
drill hole location map is shown in Figure 11-1. Table 11-2 shows the
drilling that has been conducted only within the Brisas Concession
through 2006.
TABLE 11-1
Gold Reserve Inc.
Brisas Project, Venezuela
Feasibility Study
Project Drilling Summary
Auger Drilling Auger- Diamond
Drilling Diamond Drilling Total
Year Holes Meters Hole Meters Hole Meters Holes Meters Comments
- --------------------------------------------------------------------------------------------
1993 14 404 3* 77 36 5,120 50 5,601
1994 57 1,528 59 12,649 5 422 121 14,600
1995 - - 9 1,926 99 18,997 108 20,923
1996 - - - - 252 50,221 252 50,221
1997 - - - - 219 67,946 219 67,946
1999 - - - - 13 5,726 13 5,726
2003-2004 - - - - 126 34,670 126 34,670
2005 - - - - 20 2,291 20 2,291 Non-Exploration Not in Model
2006 - - - - 68 5,775 68 5,775 Non-Exploration Not in Model
- --------------------------------------------------------------------------------------------
Total Drilling 71 1,932 68 14,652 838 191,168 977 207,751
=============================================================================================
Note: * Auger completed but not counted until diamond portion completed in 1994.
FIGURE 11-1 DRILL HOLE LOCATION MAP
GRPAHIC NOT INCLUDED
TABLE 11-2
Gold Reserve Inc.
Brisas Project, Venezuela
Feasibility Update
Brisas Concession Drilling Summary
Brisas
Type of Drilling Concession
- ------------------------------------------------------------
Auger Exploration Drilling 71
Total Length Auger Exploration Drilling (m) 3,891
Diamond Exploration Drilling 731
Total Length Diamond Exploration Drilling (m) 186,094
Metallurgicall Drilling (Diamond) 9
Total Length Metallurgical Drilling (m) 2,031
Audit Drilling (Diamond) 8
Total Length Audit Drilling (m) 2,268
Geotechnical Drilling (Diamond) 30
Total Length Geotechnical Drilling (m) 4,564
Hydrologic Test Drilling (Diamond) 25
Total Length Hydrologic Test Drilling (m) 2,270
- ------------------------------------------------------------
Total Number of Drill Holes 874
Total Length of Drilling (m) 201,118
- ------------------------------------------------------------
Total Exploration Drill Holes 802
Total Length of Exploration Drilling (m) 189,985
============================================================
11.1 Drill Hole Collar Surveys
- ----------------------------------------------------------------------
The field location of the drill hole collars before drilling and collar
surveying after drilling for all auger and core holes at the Brisas
Project have been performed by Surco, S.A., a local survey firm based
in El Callao, Venezuela. This company was also responsible for
establishing the Concession boundaries and setting up permanent survey
reference points within the Concession. The base for all surveys was
Global Positioning System (GPS) defined and checked by the survey
company with a traverse from a nearby GPS station (Las Cristinas) with
satisfactory accuracy.
11.2 Downhole Surveys
- ----------------------------------------------------------------------
The setting up of the bearing and inclination of the drill rig was made
with compass and inclinometer. All core holes were surveyed with a
Sperry Sun photographic instrument mounted inside a rod that can be
inserted into the drill hole using the drill equipment, recording
azimuth and dip at varying depths by technicians employed by Gold
Reserve. The first photo was normally taken at a depth of around 20 m
(without casing), a second photo at 6 m below the cased intervals
(below the saprolitic zone) and a photo for every 100 to 150 m
thereafter. The reading on the developed film was checked by a
geologist and the information entered into a field book.
11.3 Core Logging
- ----------------------------------------------------------------------
The logging format for the Brisas Project had several changes through
the different drilling stages as adjustments to Rock Quality Data
("RQD") measurements and standardization of lithologic and alteration
codes were made. The latest changes, which defined logging techniques
being currently followed, were implemented after drill hole D95, and
many of the previous holes were re-logged to avoid differences in log
readings. Two different log forms, geotechnical and geological, were
completed when logging.
The geotechnical log completed for each hole included depth, bit
diameter, core recovery, rock hardness, sampling intervals, and RQD.
Core recoveries were generally good averaging about 96 percent. An
average recovery of 87 percent was obtained in saprolite, and 98
percent in hard rock. The core recovery for the Blue Whale was 91
percent. RQD as measured by GRI, is the ratio between the cumulative
length of naturally unfragmented/unfractured core longer than 0.1
meters and the total core length within a 3.0 m standard measurement
interval. RQD readings were obtained before sampling and/or
destruction of the core and recorded in the logs. Drilling was
normally performed with HQ diameter (2.5 in. or 6.35 cm) to the
saprolite-hard rock contact where bits were changed to NQ diameter
(1-7/8 in. or 4.76 cm). Due to the characteristics of saprolite and
other intensely weathered rock, RQD readings were not made above the
hard rock-saprolite contact.
Detailed geological logs were recorded on a form with the following
information:
hole number, summary of location (coordinates, elevation), drilling
company, geologist, and date; and,
log description, including rock type, degree of oxidation and
weathering, intensity and type of alteration, sulfide mineralization,
veining or other structure(s) (jointing, fracturing and brecciation),
and rock color. Alteration and mineralization minerals were
quantitatively estimated and recorded, as well as all other parameters,
for computer input.
A summary log was then completed from the detailed information, along
with a graphical interpretation of the log, as well as gold and copper
assay results. Logging procedures followed by GRI were well
established and have been followed by all geologists, with minor
changes, through the different exploration stages. Quality was assured
through the use of an internal manual: "Procedures for geological
logging at Brisas del Cuyuni", which provides guidance in the use of
geological terms, defines different lithological units, structure and
visual evaluation of alteration and mineralization contents.
11.4 Twin Drilling Verification
- ----------------------------------------------------------------------
Twin hole tests were run occasionally throughout the Brisas Project
drilling program. A total of seven twin holes were drilled at
different times and locations within the property. Both the initial
and the twin were core holes. A more detailed discussion of twin hole
data results is presented in Section 14 of this Technical Report.
11.5 Condemnation Drilling
- ----------------------------------------------------------------------
Condemnation drilling has been performed extensively on the Brisas
Concession. Both condemnation and geotechnical drilling has been
performed on the waste dump areas and plant site. Geotechnical
drilling was conducted on the tailings dam area for which some assay
information was obtained. None of the drilling of these areas has
yielded geological or geochemical information suggestive of potential
ore deposits, and therefore no additional condemnation drilling is
recommended.
12.0 SAMPLING METHODOLOGY
- ----------------------------------------------------------------------
12.1 Drilling Sampling
- ----------------------------------------------------------------------
In auger drilling, each 3-meter auger flight was lifted onto a table
and the soft saprolite was peeled off, dried and prepared for
assaying. In core drilling the soft saprolite was cut longitudinally
by machete and the hard rock core cut by a standard Clipper 12-inch
diamond saw. Half of the core was placed back in the core box for
storage while the other half was placed in metal trays for drying in a
fuel oil boiler for sample preparation.
GRI has maintained a full record of split core for the entire drill
program. This core is stored in labeled boxes, each capable of holding
six 1-meter length segments. The boxes are cataloged and stacked in a
covered, guarded storage facility, from which they can be summoned for
geologic review.
The sampling interval was generally 3 meters, with the exception of
samples adjacent to the saprolite-hard rock contact, where in some
cases adjustments were made to differentiate sample types, or in a few
holes located in exploration areas outside the main mineralized zone
(e.g., D722-D727), where a 1m interval was used. The sample size was
nominally 8 kg in weight for the 3-meter sample.
The gold and copper mineralization at the Brisas Project is broadly
disseminated and amenable to bulk mining. The deposit is proposed to
be mined on 6-meter benches in ore zones and 12-meter benches in waste
zones. In PAHs opinion, the 3-meter sample length is adequate and
generally provides sufficient resolution in defining the ore and waste
zone boundaries for the mineralization except perhaps for the Blue
Whale zone which tends to be narrower and of higher grade than the rest
of the deposit and hence, a shorter interval may have allowed for better
boundary definition. On the other hand, the longer interval will tend
to incorporate some dilution to the model.
12.2 Bulk Density Determination Sampling
- ----------------------------------------------------------------------
From 1994 to 1997, there was an ongoing program totaling hundreds of
field measurements of bulk densities and moisture contents. The
following methods were used for bulk density measurements:
Method 1: known volumes were excavated from road or trench cuts and
weighed;
Method 2: boxes of drill core were weighed and adjusted for the box
weight and estimated volume of core loss; and
Method 3: individual core pieces were weighed and volumes estimated by
volume displacement.
Moisture content was measured by weighing new core, drying it overnight
and re-weighing it.
13. 0 SAMPLE PREPARATION, ANALYSIS AND SECURITY
- ----------------------------------------------------------------------
13.1 Drilling Sample Analysis
- ----------------------------------------------------------------------
Sample preparation including drying, crushing and pulverizing, was
performed on site at GRI's own sample preparation facility using the
sample preparation routine summarized in Figure 13-1. The sample pulps
were shipped to assay labs in Puerto Ordaz (Monitor and Triad) during
the earlier campaigns before 1999. The Triad lab currently located at
Minera Hecla's La Camorra mine site was used for the later round of
drilling (2003-2004). After drying, all samples were crushed to 90
percent passing minus 8 mesh (2.36 mm). Half of the crushed sample was
bagged and sorted for reference; and a split of about 500 grams from
each sample was pulverized to 95 percent passing minus 150 mesh (0.106
mm). Crushing was carried out with 6x4-inch Morse and 4x8-inch Marcy
jaw crushers and a roll crusher. Pulverizing was accomplished with
Bico puck and ring pulverizers, although Bico disk pulverizers were
also available. Pulverizer cleaning with barren sand was performed
after every ten samples. QA/QC procedures include sending pulps to
ACME Labs in Vancouver for checking one of every 20 samples and
introduction of standards prepared with the Brisas Project ore by Hazen
Labs for one of every 30 samples. Retained pulps and crushed reference
materials of samples sent to analysis are located in storage rooms at
the Brisas Project site.
Assay laboratories used during the early stages of the Brisas Project
drilling were Barringer Research Labs (Barringer) and Bondar Clegg Labs
(Bondar Clegg). Monitor Laboratories (Monitor) was used as the primary
assay laboratory and Triad Laboratory (Triad) was used as the check
assay laboratory from 1994 to 1999 when checks established confidence
for these two local labs based then in Puerto Ordaz, Venezuela. For
the 2003-2004 drilling programs, the Triad lab currently located at
Minera Hecla's La Camorra mine site was used. There is no other
commercial laboratory currently in Venezuela. Triad works with Acme
labs in Vancouver, Canada, for check assaying purposes and is also a
member of the round-robin program.
Analytical methods used for the early stage of the drilling programs
were metallic screen analysis for gold and geochemical analysis for
copper. During 1994-1999, all pulp samples were analyzed for gold by
fire assay (FA) with an atomic absorption (AA) finish; samples over 1.5
ppm Au were re-assayed with 1.0 assay ton FA with a gravimetric
finish. Copper assays were performed using standard AA with long
iodide titration verification when values were obtained above 0.3
percent copper. A second pulp of every tenth sample was sent to Triad
for check assaying using similar assay methods and procedures.
For the 2003-2004 drilling programs, samples were prepared on site and
pulps sent to Triad. The Triad lab has a certified assayer. The lab
routinely runs samples for Hecla's La Camorra mine where it is located,
and other companies operating in Venezuela. Assaying control procedures
include log record and tag identification of samples, a control list,
blank and rejects run on about 10 percent of samples, assay check runs
on one of about every 15 samples. Crucibles are specific to individual
projects and are discarded if necessary when a sample runs above a
certain value. Gold analyses were performed by fire assay with an AA
finish. Copper analyses were performed by standard geochemical
analysis with an AA finish. PAH toured the Triad lab in February 2004
and found it to be reasonably well operated. The capacity of this lab
is about 600 assays a day.
13.2 Drilling Sample Check Analysis
- ----------------------------------------------------------------------
The Brisas Project generates a large amount of assay information
consisting of original assays, checks and standards that were routinely
received. These data are kept both in original hardcopy and in digital
format. Assays are checked for correct sample number, intervals,
actual values from the lab(s) and finally for conflicts within the
primary lab, and between the primary lab and the check lab. If samples
have conflicts (i.e., [A-B]/[A+B] > 33 percent variance), they are
reviewed and if necessary the labs are requested to re-assay. In some
cases, there are up to five check assays for a given sample interval,
as shown in Table 13.1 for several high-grade gold assays. Figure 13-2
is a scatter plot showing the original assays and check assays for the
same group of samples. For standards, the tolerance is a variance of
12 percent for both Cu and Au. For drill holes with serious standard
conflicts, the entire drill hole may be requested to be re-assayed.
Once the conflicts are resolved, all assay data are kept in an
"Accepted Assays" spreadsheet under the control of the project
manager. The analysis of assays through the use of the spreadsheet as
a control has provided a reliable method of determining conflicts
between primary and check labs. This method was designed by GRI in
1995 with subsequent audits and modifications by independent parties
(Mark Springett 1995, Behre Dolbear 1997). The actual assay value
included in the drill hole database and utilized in modeling is the
average of all accepted assays for a given sample interval. The
procedures for handling the check assay data are acceptable and provide
reasonable assurance that no errors exist in the basic modeling
information derived from such data.
TABLE 13-1
Gold Reserve Inc.
Brisas Project, Venezuela
Feasibility Update
Check Assays for High Grade Gold Values
Au Assays (g/t) Original Check 1 Check 2 Check 3 Check 4
- ------------------------------------------------------------------
Count 54 54 52 38 17
Min 2.73 3.63 3.83 4.66 5.04
Max 46.08 47.45 50.33 48.87 55.79
Range 43.35 43.82 46.50 44.21 50.75
Average 13.56 14.05 14.66 14.14 17.25
Var 96.16 97.67 125.69 115.13 217.42
St. Dev. 9.81 9.88 11.21 10.73 14.75
Coef. Var 0.72 0.70 0.76 0.76 0.86
Corr.Coef. 0.96 0.95 0.94 0.89
Figure 13-1 GOLD RESERVE'S SAMPLE PREP FLOWSHEET
GRAPHIC NOT INCLUDED
Figure 13-2 HIGH GRADE Au ORIGINAL AND CHECK ASSAY COMPARATIVE GRAPH
GRAPH NOT INCLUDED
13.3 Density Analysis
- ----------------------------------------------------------------------
From 1994 to 1997, there was an ongoing program totaling hundreds of
field measurements of bulk densities and moisture contents. The
following methods were used for bulk density measurements:
Method 1: known volumes were excavated from road or trench cuts and
weighed;
Method 2: boxes of drill core were weighed and adjusted for the box
weight and estimated volume of core loss; and
Method 3: individual core pieces were weighed and volumes estimated by
volume displacement.
Moisture content was measured by weighing new core, drying it overnight
and re-weighing it.
Mr. Mark Springett, an independent mining consultant contracted by GRI,
completed a study of 304 samples in July 1996. Triad Laboratories
supervised on-site measurements using the latter two methods in 1997 to
provide an independent check of the determination. The density results
from those studies were utilized for the Brisas Project Pre-feasibility
Study (1997). In addition, more data were collected and tested during
July and August 1998. A total of 2,450 dry density measurements and
3,409 wet density measurements exist in the database and were used in
subsequent density average estimations.
In-place dry bulk densities and moisture content for different
rock/alteration types were compiled by GRI for resource/reserve studies
based on all valid information using a weighted average method (Table
13-2). The densities were used in the January 2005 Feasibility Study
and subsequent studies and are grouped by rock type and degree of
weathering. The main groups are oxide saprolite, sulfide saprolite,
weathered rock, unweathered rock, and Blue Whale material. An
additional category was created for schist because it consistently has
a lower density for either weathered or unweathered rock than other
rock types that are generally considered as "tuff".
TABLE 13-2
Gold Reserve Inc.
Brisas Project, Venezuela
Feasibility Update
Bulk Densities and Moisture Contents by Rock Type
Rock Type Dry Bulk Density (t/m3) Moisture Content
- ----------------------------------------------------------------------
Oxide Saprolite 1.43 23%
Sulfide Saprolite 1.72 16%
Weathered Hard Rock (schist) 2.29 8%
Weathered Hard Rock (tuff) 2.38 6%
Unweathered Hard Rock (schist) 2.77 1%
Unweathered Hard Rock (tuff) 2.89 0%
Blue Whale 2.76 1%
14.0 DATA VERIFICATION
- ----------------------------------------------------------------------
14.1 Data Verification and Validation
- ----------------------------------------------------------------------
GRI's QA/QC program included the insertion of assay standards prepared
by certified labs with the Brisas Project core samples into the
mainstream samples, and routine checks by a secondary lab as explained
in Section 13. Labs used for standards included Hazen Research, Triad,
and CDN Resource Laboratory in Canada. One standard sample was inserted
for every 20 samples and one check sample was sent to a secondary lab
for every 10 samples throughout the drilling campaigns, except for
2003-2004 when 1 in 20 samples were checked and 1 in 30 samples was a
standard.
The reliability of assay results was tested throughout the drilling
programs including several specific detailed studies by independent
parties. Mr. Mark Springett carried out studies on the reliability of
sampling and assaying in 1995 and 1996 and concluded that the results
from the labs (250 samples) showed a satisfactory level of precision
and were unbiased relative to each other. Behre Dolbear (BD) performed
an independent check assay program of 36 samples from six holes in 1997
to check assays produced by Monitor or Triad labs against results from
a third lab (Bondar Clegg). Samples were selected with values at
different ranges of gold grades. BD's check assay results showed high
correlation coefficients for both gold (0.92) and copper (0.99) and
mean values within about 5 percent of each other for both metals.
In 1997, GRI and BD jointly drilled six core holes under BD's direct
supervision and conducted assays independently at different labs. BD
concluded that procedures utilized to collect assay data met or
exceeded industry standards and that the assay results from all labs
(Bondar Clegg, Monitor and Triad), were reliable.
After assays are received by the project manager a copy is forwarded to
the technical department. Archives of both digital (diskette) and
certified paper copies from the lab are maintained in the Technical
office files. Assay results are transferred from ASCII format into
Microsoft Excel spreadsheets by the technicians. This procedure
involves copying from the digital form as well as some hand entered
values. The entered values are checked by the technician and then
approved by the project manager. No other personnel other than the
technical office staff are permitted to transfer the assay data, and
the computer database is controlled solely by the manager.
PAH conducted several data verifications and validations for the
January 2005 Feasibility Study. PAH visited the Brisas Project
facilities, toured the lab preparation and core shack areas, and
inspected the core and several drill sites during the 2003-2004
drilling campaign in February 2004. PAH visited GRI's offices in
Spokane, Washington to review the original drill hole logs and assay
sheets in April 2004.
PAH verified the drill log data and assays against the drill hole
database used for the Brisas Project feasibility study. Ten holes
located in ten different vertical sections throughout the Brisas
Project were checked for collar location, downhole survey, assaying and
geological/geotechnical information. Minor discrepancies were found in
survey and lithology information between the database and the logs; no
errors or discrepancies were found on assay information. It was found
that several holes in the early stages of the drilling campaigns were
not surveyed for downhole deviation (e.g., most AD holes and some D
holes). All AD holes were apparently given an average of the deviation
observed in the few (about 20 percent) that did have deviation
measurements. The downhole deviation can be up to about 40 meters on
long holes (e.g., AD85 at a depth of 362 meters), however, the average
depth of the AD holes is 214 meters and the average depth of the A
holes is 27 meters. The number of holes affected is less than 10
percent of the current database and the area covered has been drilled
at closer spacing by later campaigns with deviation measurements.
Therefore, the lack of down hole surveying in these holes does not
appear to greatly influence the model. Also, auger holes were visually
inspected in cross sections and showed generally good agreement with the
much more abundant surrounding core hole data.
14.2 Twin Drilling Verification
- ----------------------------------------------------------------------
Twin hole tests were run occasionally throughout the drilling
program. A total of seven twin holes were drilled at different times
and locations within the property (Figure 14-1). Both the initial and
the twin were core holes. Visual inspection of twin drill hole
intersects on cross section indicates overall a very good
correspondence of mineralized areas in terms of location, length of the
zones, and distribution of Au and Cu grades (Figure 14-2), although the
comparison of individual samples shows some variability due to natural
deposit local variations (nugget effect).
Table 14-1 shows a summary of the twin hole data. The comparison shows
good reproducibility of sampling data, but also suggests consistently
lower grades mainly for Au, but also for Cu in the twin or A holes,
relative to the original core holes. It should be noted that while
this apparent bias may be due, at least partially, to the highly
variable distribution of gold within the deposit, it is in some cases,
also the result of having a single very high grade assay skewing the
overall average for the hole(s) as seen in Table 14-2, for example for
holes D404/D404A and D498/D498A. Without these assays the results
compare much closer.
The A holes and a few others were drilled in 1999 by GRI under the
direct supervision of the consulting firm Behre Dolbear (BD) as part of
an independent verification of the drilling and assaying programs at the
Brisas project. In order to better understand the apparent bias on the
A holes, PAH requested that GRI drill a hole (D754) as a twin hole to
one of another BD holes drilled in 1999 (D614). As seen in Table 14-1,
the PAH hole returned average grades slightly lower than the BD hole for
Au and about the same grade for Cu, indicating that a bias more likely
does not exist on the sampling and assaying data and as such the twin
hole data generally confirm the original assay results.
TABLE 14-1
Gold Reserve Inc.
Brisas Project, Venezuela
Feasibility Update
Twin Hole Data (Au and Cu grade)
Initial Hole Twin Hole ("A" Hole)
--------------------------- ----------------------------
Interval Ratio(Au) Ratio(Cu)
Drill Site # Length Hole-ID Length Au(gpt) Cu(%) Hole-ID Length Au (gpt) Cu(%) Twin/Orig. Twin/Orig.
- ----------------------------------------------------------------------------------------------------------------
1 350 D548 353 0.389 0.042 D548A 350 0.369 0.038 0.949 0.905
2 119 D328 155 0.499 0.251 D328A 303 0.390 0.207 0.782 0.825
3 210 D260 211 0.392 0.099 D260A 369 0.376 0.097 0.959 0.980
4 148 D404 148 0.850 0.391 D404A 160 0.655 0.372 0.771 0.951
5 341 D498 383 0.407 0.016 D498A 341 0.372 0.016 0.914 1.000
6* 179 D476 179 0.183 0.015 D637 200 0.190 0.014 1.038 0.933
7 251 D754 252 0.428 0.236 D614 251 0.450 0.229 1.051 0.970
- ----------------------------------------------------------------------------------------------------------------
Overall Ave. 1,598 All Samples 1,681 0.427 0.119 All Samples 1,974 0.391 0.112 0.916 0.938
- ----------------------------------------------------------------------------------------------------------------
Overall Ave.
without high
grade
outliers 1,598 All Samples 1,681 0.406 0.117 All Samples 1,974 0.391 0.112 0.963 0.961
- ----------------------------------------------------------------------------------------------------------------
* DH Traces are 7 to 12 m apart
TABLE 14-2
Gold Reserve Inc.
Brisas Project, Venezuela
Feasibility Update
Twin Hole Data (Average Au and Cu grade Maximums and Minimums)
Initial Hole Twin Hole ("A" Hole)
---------------------------------------- -----------------------------------------------
Interval
Drill Site # Length Hole-ID Au(Max) Au(Min) Cu(Max) Cu(Min) Hole-ID Au(Max) Au(Min) Cu(Max) Cu(Min)
- ----------------------------------------------------------------------------------------------------------------
1 350 D548 2.924 0.011 0.680 0.003 D548A 2.018 0.011 0.244 0.002
2 118 D328 1.92 0.044 1.368 0.011 D328A 1.369 0.054 1.304 0.011
3 210 D260 1.615 0.040 0.847 0.004 D260A 1.639 0.027 0.375 0.007
4 148 D404 5.188 0.030 4.345 0.002 D404A 4.067 0.005 4.404 0.003
5 341 D498 4.376 0.018 0.234 0.001 D498A 2.371 0.005 0.195 0.001
6* 179 D476 1.111 0.005 0.078 0.001 D637 0.995 0.005 0.056 0.001
7 251 D754 2.93 0.020 1.432 0.005 D614 4.029 0.018 1.326 0.001
* DH Traces are 7 to 12 meters apart
Figure 14-1 TWIN CORE HOLE LOCATION MAP
GRAPHIC NOT INCLUDED
Figure 14-2 TWIN CORE HOLES SHOWING GOLD ASSAYS-SECTION 682300N
GRAPHIC NOT INCLUDED
15.0 Adjacent Properties
- ----------------------------------------------------------------------
Adjacent to the northern boundary of the Brisas Project is the Las
Cristinas property. It includes a continuation of the gold-copper
mineralization found on the Brisas Project with the same
north-northeast striking, northwest-dipping broad shear structures.
Four contiguous concessions known as Las Cristinas 4, 5, 6, and 7 make
up the property (Figure 4-2). In total these concessions cover an area
that is 5 by 2 kilometers. Exploration was conducted by Minera Las
Cristinas C.V. (MINCA), a joint venture between Placer Dome de
Venezuela C.A. (Placer Dome) as 70 percent shareholder, and Corporation
Venezolana de Guyana (CGV) as a 30 percent shareholder. The joint
venture drilled over 1,000 holes with a total length of over 110,000
meters. Placer Dome completed a Feasibility Study for the project in
March 1996. Construction began on the project August 2, 1997 but was
suspended on July 15, 1999 due to low gold prices and property title
lawsuit issues. At the time construction was suspended it was
estimated that Placer Dome had spent $118 million on the project.
CVG controls the property at the present time; however, it granted an
operations contract to Crystallex International Corporation
(Crystallex) in September 2002. A resource/reserve estimate for the
project was completed by Mine Development Associates (MDA) on April 30,
2003. These results were filed on SEDAR as the Technical Report titled
"Resources and Reserves, Las Cristinas Gold and Copper Deposits,
Bolivar State, Venezuela" prepared by MDA. The measured and indicated
resource was estimated at 439 million tonnes with an average gold grade
of 1.09 gpt for a total of 15 million contained ounces based on a gold
cutoff grade of 0.5 gpt. Proven and probable mineral reserves were
estimated at 224 million tonnes with an average gold grade of 1.33 g/t
containing 9.54 million ounces.
Subsequent to the filing of the 2003 Technical Report by MDA there has
been other resource and reserve estimates released by Crystallex, and
an updated Technical Report was filed on SEDAR in August 2005 based on
a new Development Plan. This Technical Report shows proven and
probable reserves at Las Cristinas are 294 million tonnes grading 1.32
gpt for a total of 12.5 million contained ounces.
The Feasibility Study for Las Cristinas was completed in 2004 and a
Development Plan in 2005 by SNC Lavalin. Currently, Crystallex is in
the process of advancing the project.
16.0 Metallurgy and Mineral Processing
- ----------------------------------------------------------------------
The Brisas Project consists of four ore types. The quantities and
grades of these ores are summarized in Table 16-1. Hard-rock ore
comprises about 95 percent of the ore with the remainder split
approximately into 42 percent oxide saprolite and 58 percent sulfide
saprolite ores. Metallurgical testwork has been conducted on all four
ore types and on blends that simulate the blends projected for the
industrial operation. This section describes the metallurgical
testwork that has been conducted and provides a brief description of
the Feasibility process plant design.
TABLE 16-1
Gold Reserve Inc.
Brisas Project, Venezuela
Feasibility Update
Ore Processing, Ore Types and Grades
Quantity Gold Copper
(million Grade Grade
Ore Type tonnes) (grams/tonne) (percent)
- --------------------------------------------------
Saprolite
Oxide 10 0.79 0.05
Sulfide 13 0.78 0.10
Total/Average 23 0.78 0.07
Hard Ore
North ore 264 0.56 0.21
South ore 198 0.80 0.03
Total/Average 462 0.66 0.13
- --------------------------------------------------
TOTAL AVERAGE 485 0.67 0.13
==================================================
16.1 Metallurgical Testwork
- ----------------------------------------------------------------------
As is common in the development of mining projects, there have been a
series of sample collection and testing campaigns for the Brisas
Project leading to the development of an acceptable flow sheet and
processing strategy. From 1992 to January 2005, 20 different
metallurgical test programs and mineralogical investigations were
completed on the Brisas Project ores. In addition, there were five
pressure oxidation test programs using copper concentrate and six
tailings analysis and characterization reports were completed.
The earlier test programs were as follows:
Flotation and cyanidation testwork on oxide and sulfide saprolite
composites by Lakefield, 1994.
Gravity, flotation, and cyanidation testwork on oxide saprolite,
sulfide saprolite, and hard rock composites by Hazen, 1996.
Gravity, flotation, and cyanidation testwork on six composites made up
from oxide saprolite, sulfide saprolite, and four major hard rock
samples by RDI, 1997.
Grinding testwork on hard rock samples by MacPhearson, 1997. Grinding
testwork has produced a Gross Autogenous Work Index of 21.3 and a Bond
Ball Mill Work Index of 15.4.
Pilot plant testing of a large bulk sample obtained from a small shaft
and underground development in the north area of hard rock ore. The
purpose of this campaign was to generate a large quantity of
concentrate to evaluate several hydrometallurgical and two
pyrometallurgical processes to treat the concentrates on site.
Following the testwork it was decided not to pursue on-site concentrate
treatment for the present. The tests were conducted by Lakefield, 2004.
The latest testwork was conducted by Lakefield and reported in January,
2005. The testing was done on all four ore types, comprising the
following six groups of samples:
Oxide Saprolite (Sept. 2004): Composite sample obtained from four
hand-augured samples
Sulfide Saprolite (Sept. 2004): Composite sample obtained from 27 drill
hole intervals
Hard-Ore North (May 2004): Composite sample obtained from 31 drill hole
intervals
Hard-Ore South (May 2004): Composite sample obtained from 29 drill hole
intervals
Hard-Ore North (Sept. 2004): Composite sample obtained from 25 drill
hole intervals
Hard-Ore South (Sept. 2004): Composite sample obtained from 25 drill
hole intervals
PAH reviewed maps of the locations of the samples used in the latest
testwork in relation to the current mine in order to assess whether
they were representative of the planned production. Based on this
review, PAH considers the samples representative. The two saprolite
sample composites each weighed about 100 kilograms; the four hard-rock
samples each weighed about 75 kilograms. The head assays of the
composites were close to the average ore grades of the ore deposit they
represent.
The intention is to process the saprolite ores in conjunction with the
hard ores. Saprolite sulfide ore will constitute about 7 percent of
the ore feed during the first seven years of operation and cease
thereafter. Oxide saprolite ore will constitute about 3 percent of the
ore feed throughout the life of the mine.
Earlier flotation testwork on the hard-rock drill composites conducted
at all three testwork laboratories (Hazen, Lakefield, and RDI) had
shown that the north ore can produce a marketable copper/gold
concentrate but that the south ore could not. Accordingly, Lakefield,
in the latest tests, conducted a series of tests of various blends of
the north and south ore composites. The tests undertaken were as
follows:
Gravity separation (22 tests)
Batch flotation to determine optimum flotation conditions (18 tests)
Locked-cycle flotation (8 tests)
The testing program followed the intended flow sheet which incorporates
conventional mineral dressing processes: SAG and ball mill primary
grinding, gravity separation, froth flotation, cyanidation, CIL, carbon
elution and electrowinning to recover gold. The process flow sheet is
discussed in the next sub-section of this report, Section 16.2, Plant
Design.
The locked cycle tests were examined more closely as they provide a
better indication of actual mill performance than do batch tests
alone. The locked cycle tests completed in the latest test program
used the flotation conditions determined by the batch floatation
tests. Results of this testwork are summarized in Table 16-2. The
locked cycle tests were completed using three different ratios of North
and South Hard rock ores, 50%-N:50%-S; 60%-N:40%-S; 40%N-60%S. A
minimum of two locked cycle tests were completed on these three
blends. There is a possibility that the processing of the sulfide
saprolite ore in conjunction with the hard rock ores could
deleteriously affect the process. Therefore, a fourth ore blend was
tested in locked cycle, which incorporated sulfide saprolite in the
following ratios: 52%-N:41%-S:7%-sulfide saprolite. An arithmetic
average of the results for the locked cycle tests is shown in Table
16-3.
By blending both north, south, and saprolite ores it is possible to
obtain an acceptable concentrate grade, and that is the planned
operating strategy for the project. The addition of sulfide saprolite
to the process feed did not appear to compromise copper concentrate
grade or metal recoveries. The latest locked cycle test results
compared favorable to the values used for the process Design Criteria
in the Feasibility Study.
Prior to 2006 the plans had been to feed the oxide saprolite directly
to the cyanide leach circuit, bypassing the flotation circuit. In
2006, it was decided that it was more economic to feed the oxide
saprolite to the flotation circuit at a reduced rate. It is surmised
that the small proportion of this stream in the plant feed (about 2 1/2
percent) will not adversely affect the flotation of the other ores.
While this is probably true, PAH considers it worthwhile testing it and
has included this as one of the recommendations.
Cyanide leaching tests of the cleaner scavenger tails generated in the
hard-ore flotation tests showed this to work acceptably, though cyanide
consumption was high when a high concentration of cyanide was used. At
1 gram per liter cyanide concentration, cyanide consumption varied from
1.6 to 3.3 grams per tonne of material treated; tests at 0.5 grams per
liter cyanide strength reduced cyanide consumption by about 30 percent.
In summary, PAH considers the sampling and testwork acceptable except
for testing the effect of adding saprolite oxide ore to the flotation
feed, as mentioned previously.
TABLE 16-2
Gold Reserve Inc.
Brisas Project, Venezuela
Feasibility Update
Ore Processing, Testwork Summary
Item Units Value
- -----------------------------------------------
Head Grade
Gold grams/tonne 0.69
Copper percent 0.15
Recovery
Gold
Gravity concentrate percent 14.9
Flotation concentrate percent 49.5
Cleaner scavenger tails percent 16.6
Total percent 81.0
Copper percent 86.6
Copper Concentrate Grades
Average percent 22.1
TABLE 16-3
Gold Reserve Inc.
Brisas Project, Venezuela
Feasibility Update
Average of the Results for the Locked Cycle Tests
Ore Blend Ratio
North:South: Assay Recovery
Sulfide Sapr Product Cu,wt% Au,g/t Cu,wt% Au,g/t
- ----------------------------------------------------------------------
50:50 Gravity Conc. 1911 17.1
Copper Conc. 23.2 63 83.1 46.4
1st Cleaner Scav. Tail. 0.30 2.38 14.4 23.1
Rougher Tail 0.004 0.10 2.57 13.4
Head 0.147 0.713 100.0 100.0
60:40 Gravity Conc. 3030 13.7
Copper Conc. 23.3 55 87.5 52.0
1st Cleaner Scav. Tail. 0.21 1.785 10.5 22.3
Rougher Tail 0.004 0.08 2.05 12.0
Head 0.160 0.635 100.0 100.0
40:60 Gravity Conc. 3563 14.5
Copper Conc. 18.25 61.7 86.9 50.9
1st Cleaner Scav. Tail. 0.16 1.81 10.9 21.6
Rougher Tail 0.003 0.105 2.2 13.1
Head 0.125 0.715 100.0 100.0
52:41:7 Gravity Conc. 478 17.9
Copper Conc. 28.7 70.1 85.7 41.9
1st Cleaner Scav. Tail. 0.23 2.3 10.8 21.4
Rougher Tail 0.006 0.15 3.5 18.8
Head 0.15 0.760 100.0 100.0
16.2 Plant Design
- ----------------------------------------------------------------------
Aker Kvaerner completed the Feasibility plant design and cost estimates
in early 2005. SNC made some minor modifications to the circuit in
early 2006, primarily changing the leach circuit from Carbon-in-Pulp
(CIP) to Carbon-In-Leach (CIL).
Principal ore processing parameters for the intended plant are
presented in Table 16-4. The values are based on testwork results that
proceeded issue of the latest testwork report. All of the parameters
are in good agreement with the latest testwork with the exception of
gold recovery and concentrate grade, both of which are marginally
higher than the latest testwork results. The difference in gold
recovery is within the expected range of accuracy of this parameter.
The higher copper concentrate grade is based on the fact that the
quantity of final concentrate produced in the laboratory test was so
small that it became diluted with gangue mineral; this problem should
not occur in an industrial plant. A simplified flow diagram of the
plant is shown in Figure 16-1. A listing of the principal equipment is
given in Table 16-5.
Table 16-4
Gold Reserve Inc.
Brisas Project, Venezuela
Feasibility Update
Ore Processing, Principal Parameters
Item Units Value
- --------------------------------------------------------------
Processing Rate
Hard ore
Annual million tonnes/year 25.2
Daily tonnes/day 70,000
Saprolitic ore
Oxide (for 17.5 years) tonnes/day 2,000
Sulfide (for 7 years) tonnes/day 5,400
Ore Grade
Gold grams/tonne 0.67
Copper percent 0.13
Recovery
Gold percent 83
Copper percent 87
Concentrate Grade
Gold grams/tonne 90
Copper percent 24
Capital Cost
Mill $ millions 242
Tailings - Stage 1 $ millions 14
Operating Cost $/tonne milled 2.59
The plant design is conventional, using some of the largest processing
machinery currently available. There will be two grinding/flotation
lines. A gravity concentrate will be recovered in the grinding circuit
and will be shipped directly as gravity concentrates. The ore processed
through the grinding and
FIGURE 16-1 SIMPLIFIED OVERALL PROCESS FLOW DIAGRAM
DIAGRAM NOT INCLUDED
TABLE 16-5
Gold Reserve Inc.
Brisas Project, Venezuela
Feasibility Update
Ore Processing, Principal Equipment List
Quantity Power
Item Description Oper. S'by. (kW each)
- -------------------------------------------------------------------------------
FLOTATION CIRCUIT
Primary crusher Gyratory, 60-in x 89-in 1 600
Crusher discharge feeder Apron, 8-ft wide 1 375
Transfer conveyor Belt, 84-in wide 1 500
Saprolite sulfide stockpile 9 million tonnes 1
Saprolite oxide stockpile 9 million tonnes 1
Saprolite crusher feeder Apron, 3-ft wide 1 45
Saprolite crusher MMD 625 toothed roll 1 150
Overland conveyor Belt, 60-in wide, 5.5 km long 1 4,480
Coarse ore stockpile Conical, 35,000 tonnes live 1
Reclaim feeders Apron, 5-ft wide 6 55
Reclaim conveyors Belt, 60-in wide 2 300
SAG mills 36-ft dia. x 19-ft long 2 13,500
Ball mills 22-ft dia. x 36.5-ft long 4 9,325
Pebble crusher Nordberg HP500 2 375
Cyclone feed pumps 20-in x 18-in. 4 1,100
Cyclone banks 26-in 4
Gravity concentrators 4 55
Rougher flotation cells 160-cu. m., banks of 6 4 188
Regrind mills Metso VTM1250 Vertimill 2 932
First cleaners 130-cu. m., bank of 3 1 150
Cleaner scavenger 130-cu. m., bank of 2 1 150
Second cleaners 17-cu. m., bank of 5 1 30
Third cleaners 17-cu. m., bank of 3 1 30
Fourth cleaners Column, 2.8-m. dia. 2
Concentrate thickener High rate, 9-m dia. 1 8
Concentrate filter Pressure, 45-sq. m area 1
Concentrate storage bunker 1,200-tonne capacity 1
Tailings thickeners High rate, 72-m dia. 1 22
Tailings pumps 18- x 16-in. 2 2 375
CONCENTRATE SHIPPING
Conc. transport trucks Rear-dump, 18-tonne capacity 25
Port conc. storage bldg. 20,000-tonne capacity 1
Ship loading system Hopper and belts 1
CYANIDATION CIRCUIT
Pre-leach thickener High-Rate, 30-m dia. 1 8
CIL tanks Stirred tanks, 13.6-m dia.
x 14-m high 6 75
Carbon processing Stripping and electrowinning 1
Carbon reactivation Rotary kiln, electric heat 1 1,000
Refinery Induction furnace 1 125
Cyanide destruction Inco Air-SO2 system 1
flotation plant will be a blend of North and South hard ore with about
7 percent saprolite sulfide ore in the feed for the first seven years
of operation and about three percent saprolite oxide ore throughout the
life of the mine. A cyanidation leaching system will process the
cleaner flotation tails.
Flotation concentrate will be trucked to Puerto Ordaz and loaded onto
ships for transport to smelters. Gravity concentrate and the dore
produced from cyanidation of the flotation cleaner scavenger tails will
be shipped to overseas refineries.
Tailings will be placed in a conventional tailing containment close to
the plant. Initially, borrow from inside the tailing containment will
be used to dam three sides on a gently-inclined plane to build a
horseshoe-shaped enclosure with an edge length of about 3 kilometers.
The dam wall will be periodically raised using mine waste rock, using
the "centerline" method of raising the wall. The dam will have
sufficient capacity for the full amount of the ore to be mined. Decant
water will be reclaimed and recycled to the plant and excess will be
discharged into the general drainage.
17.0 MINERAL RESOURCE AND MINERAL RESERVE ESTIMATES
- -------------------------------------------------------------------------------
This report was prepared for GRI to update the results of the Brisas
Project Feasibility Study that was completed in January 2005. This
Technical Report is based largely on information originally presented
in the January 2005 Feasibility Study by Aker Kvaerner (AK), for which
PAH provided the geology, mining, and economic sections under a
subcontract to GRI. In addition, subsequent studies by PAH, SNC
Lavalin and Marston have updated resources, reserves and capital and
operating costs. Information contained in this report is based on
information available to PAH at the time of the report, including
information generated by PAH as well as information supplied by GRI and
other third party sources. PAH believes that the information contained
herein will be reliable under the conditions and subject to the
limitations set forth herein. PAH does not guarantee the accuracy of
third party information that was reviewed by PAH, including property
legal title information, geotechnical issues, environmental issues, and
process issues.
PAH developed the resource model and Marston developed the resource and
reserve estimates based on information provided by GRI and other
consultants. These estimates are based on the latest operating plans
and financial information regarding the project.
17.1 Coordinate System, Surveying, and Topography
- -------------------------------------------------------------------------------
GRI provided digital topographic information for the Brisas and Barbara
Concessions and the surrounding area. Information for the Brisas and
Barbara concessions was based on detailed surveys of the concessions
that were contracted by GRI. These surveys were completed during
numerous programs, the last of which was completed in early 2005.
Modeling and resource and reserve estimates were based on the GRI April
2005 topography.
As a check of drill hole collar elevation integrity, drill hole collar
elevations were compared against digital topography on vertical
sections and plans, both showing good agreement.
17.2 Sample Database
- -------------------------------------------------------------------------------
As discussed in Section 11, GRI began exploration activity in late 1992
and continued various drilling programs through the present time. A
summary of the drill hole database used for resource modeling is shown
in Table 17-1. Drill holes that were drilled since April 2005 are not
included in the summary. They were not used in resource modeling
because they were not drilled for exploration purposes. A drill hole
location map is shown in Section 11 (Figure 11-1).
TABLE 17-1
Gold Reserve Inc.
Brisas Project, Venezuela
Feasibility Update
Drill Hole Database Summary
Item
- -----------------------------------------------------------
Total Number of Drill Holes 874
Number of Auger Holes 71
Number of Core Holes 803
Total Drilling Length (m) 201,118
Number of Sample Intervals 63,015
Number of Samples with Au Assays 62,684
Number of Samples with Cu Assays 61,090
Shortest Drill Hole (m) 4.5
Longest Drill Hole (m) 998.1
Maximum North (m) 683,109.9
Minimum North (m) 680,561.4
Maximum East (m) 670,851.0
Minimum East (m) 668,442.6
Maximum Collar Elevation (m) 147.0
Minimum Collar Elevation (m) 128.3
Number of Holes Surveyed Downhole 738
Number of Vertical Holes (Dip: -90 to -85 degrees) 201
Number of Inclined Holes 632
Flattest Inclined Hole Dip Angle (degrees) -45.0
Number of Horizontal Holes 0
17.3 Resource Model Setup
- -------------------------------------------------------------------------------
As discussed earlier, the primary mineralized zones have been weathered
to saprolite near the surface. The thickness of the saprolite clays is
generally around 60 meters. Copper in the saprolite zone has been
significantly redistributed due to supergene leaching and enrichment.
Gold in saprolite, however, appears to have limited redistribution as
indicated by the continuity of gold grade distribution from hard rock
to saprolite.
A weathering profile model was constructed to account for vertical
variations in rock types and in the distribution of the copper
mineralization. Three-dimensional surfaces were constructed for the
bottom of the oxide saprolite, sulfide saprolite and weathered rock
horizons using the corresponding drill hole intercepts. The weathering
profile model largely controlled the rock density model as well (Table
17-2).
The mineralized zones consisted of modeling the Blue Whale zone, the Au
mineral envelope, and the Cu mineral envelope as described below.
TABLE 17-2
Gold Reserve Inc.
Brisas Project, Venezuela
Feasibility Update
Rock Type and Density Model Codes
Rock Type Rock Code Dry Bulk Density (t/m3)
- ----------------------------------------------------------------------
Air 0 0
Oxide Saprolite 11 1.43
Sulfide Saprolite 12 1.72
Weathered Hard Rock (Schist) 13 2.29
Weathered Hard Rock (Tuff) 13 2.38
Unweathered Hard Rock (Schist) 1 2.77
Unweathered Hard Rock (Tuff) 1 2.89
"Blue Whale" 61 2.76
Drill hole sample values were composited into 6-meter down-hole
intervals to normalize the different sampling intervals found in the
database. The compositing process simulates the grade distribution
typically encountered in a mining operation. The averaging effects of
compositing can also be used to incorporate some dilution into the
project. A downhole composite was selected over a bench composite to
maintain a constant composite length since some holes are vertical and
many inclined.
17.4 Mineralized Rock Model
- -------------------------------------------------------------------------------
It has been observed for some time within the Brisas Project that the
mineralization generally follows a structural trend that is
sub-parallel to the rock unit trend present in the area. Attempts by
GRI geologists to define other clear controls of mineralization such as
lithological controls to improve the modeling have proven to be
inconclusive except for the Blue Whale rock zone and the weathering
profile. The experience at the Brisas Project also shows that gold is
stable during the weathering process and hence the original gold
distribution is unchanged. However, copper is unstable because of
weathering and is generally leached out from the oxide saprolite zone
and locally enriched in the sulfide saprolite zone by supergene
process. Furthermore, the gold and copper occurrence within the
property varies for each metal as seen previously in the geology and
mineralization discussion. Therefore, the resource model is based on
constructing separate mineral envelopes for Au and Cu that follow the
general geologic trend and structural control of the Brisas zone and,
in the case of copper, the weathering profile as well. The Blue Whale
is modeled separately.
The Blue Whale was digitized on vertical sections spaced 25 meters
apart following the lithologic contacts and assay values. The
interpretations on section were then transferred to plan views spaced 6
meters apart to be used as reference. A mineralized envelope was then
digitized on a bench-by-bench basis following a similar approach as the
vertical sections. Finally, the bench envelopes were linked together to
define a 3D solid that represents the Blue Whale mineralization.
The Cu mineral envelope was generated section by section spaced 50 or
25 meters apart using a nominal 0.08 percent cutoff grade. Generally,
a minimum of two adjacent composites (on same hole) and at least two
holes were needed to make a zone. The general geologic trend of the
mineralization both on strike and downdip was followed for weathered
rock and hard rock; for saprolite (both oxide and sulfide) a generally
horizontal trend was applied. Section interpretations were then linked
together to construct a 3D solid.
The Au mineral envelope was generated section by section spaced 50 or
25 meters apart using a nominal 0.25 gpt cutoff grade. Generally, a
minimum of two adjacent composites (on same hole) and at least two
holes were needed to make a zone. The general geologic trend of the
zone on strike and downdip was followed throughout. Section
interpretations were linked together to construct a 3D solid.
A block model was constructed in Gemcom (R) software with the following
geometry (Table 17-3).
TABLE 17-3
Gold Reserve Inc.
Brisas Project, Venezeula
Feasibility Update
Block Model Geometry
Northing Easting Elevation
- --------------------------------------------------------------------
Origin (sw-top corner) 680,000 668,000 150
- --------------------------------------------------------------------
Block Size (meters) 10 10 6
- --------------------------------------------------------------------
Number of Columns 300
Number of Rows 400
Nubmer of Levels 140
Rotation 0
Blocks were tagged with codes for air or rock types as follows (Table 17-4):
TABLE 17-4
Gold Reserve Inc.
Brisas Project, Venezuela
Feasibility Update
Mineral Envelope Model Codes
Metal Zone Rock Code
- --------------------------------------------------------------------
Gold Air 0
Within 0.25 gpt Mineral Envelope 10
Blue Whale 61
Outside Mineral Envelope 1
Copper Air
Within 0.08% Mineral Envelope - Oxide Saprolite 22
Within 0.08% Mineral Envelope - Sulfide Saprolite 21
Within 0.08% Mineral Envelope - Hard Rock 20
Blue Whale 61
Outside Mineral Envelope - Oxide Saprolite 12
Outside Mineral Envelope - Sulfide Saprolite 11
Outside Mineral Envelope - Hard Rock 1
17.5 Statistical Analysis and Variograms Grade Estimation and
Validation
- -------------------------------------------------------------------------------
Since the Feasibility Study was completed, 24 additional exploration
diamond holes were drilled. These drill holes were included in the
resource model updated by PAH in April 2005, which is the basis for the
resource and reserve estimates contained in this technical report.
Mineral envelopes were adjusted to incorporate this additional
drilling. No new variograms were run for this update considering that
the new drilling was quite localized and relatively minor when compared
to the vast amounts of already existing data. Variogram model
parameters were the same as those used for the Feasibility Study model.
17.5.1 Gold Review
- -------------------------------------------------------------------------------
Examination of the log-probability plot for uncapped 6-meter composites
within the interpreted grade envelope shows a break in the distribution
around 4 to 5 g/t with another break around 8.5 g/t indicating some
mixing of grade populations that have not been completely segregated.
PAH does not believe that that this minor mixing is significant (Figure
17-1). The coefficient of variation (CV) for these uncapped composites
is 1.58.
Capping of grades was conducted to adjust for the effects of
statistical outlier grades. Capping was a judgment call about
mineralization distributions based on the understanding of the overall
geologic environment and trading off the capping threshold against
estimation parameters to yield a final result that looks appropriate.
Gold composites were capped at 8.5 g/t.
Based on the geologic description of the deposit, it appears that the
portion of the distribution over the 4 to 5 g/t threshold is that which
is more distinctly structurally controlled versus the more disseminated
mineralization below the threshold. A look at composite maps and
computed indicator variograms for continuity of grades above that
threshold show inconclusive results. While one may see a grouping of
two high grades in the same vicinity, one most often sees lone higher
grades intermixed with grades below the threshold. This suggests that
trying further to delineate zones within the mineralized envelope would
not be worthwhile.
The log-probability plot of uncapped Blue Whale composites shows a
single distribution with a somewhat high-grade tail (Figure 17-2).
This suggests that the Blue Whale mineralization is defined fairly well
by the geologic controls, or that its complexity may not be fully
evidenced by the relatively small number of composites. For this
distribution an 8.5 g/t capping threshold was applied to composites.
Capping these two distributions lowers their Coefficient of Variations
(CV) to 1.23 for the mineralized envelope and 0.92 for the Blue
Whale. The CV for the Blue Whale distribution is down to a level where
linear estimation techniques should perform reasonably well. However,
the CV for the mineralized envelope is at a level where
straight-forward linear techniques often result in overly-smoothed
estimates.
FIGURE 17-1 Log-Probability Plot of Uncapped 6m Composite
GRAPH NOT INCLUDED
FIGURE 17-2 Log-Probability of Uncapped Blue Whale Composites
GRAPH NOT INCLUDED
Generally, in a distribution with a CV less than 1, linear estimation
techniques such as inverse distance or linear kriging work well. A CV
greater than two, more often than not, requires indicator kriging.
Between one and two is a gray area that, unfortunately, seems to
include a large number of gold deposits. In this CV range,
single-indicator techniques such as restricted kriging or the use of
parameters for linear techniques that minimize smoothing, while not
giving too much influence to the high-grades through multiple
estimation passes, work well. The Brisas model uses ordinary kriging
(OK) with multiple passes, based on the nested structures of the
variograms.
Figures 17-3 through 17-6 show computed correlograms for the gold
mineralized envelope and the Blue Whale and fit spherical models. Two
structures were modeled for each direction: 1) ranges of 31 and 130
meters in the strike direction; 2) ranges of 28 and 144 meters in the
dip direction; and, 3) ranges of 21 and 50 meters across the dip
direction. For the Blue Whale one structure was modeled with ranges of
81 and 126 meters.
17.5.2 Copper Review
- -------------------------------------------------------------------------------
Copper 6-m composite distributions for the different rock types within
the mineralized envelope, i.e., Zone 20 (hardrock), Zone 21 (ox-sap),
and Zone 22 (sulf-sap) were examined. Grade capping is less of an
issue for copper than it is for gold. The Cu distributions seem to
have few outliers and, even uncapped, have CVs less than or equal to
one, indicating better behaved population distribution. Figure 17-7
shows the log probability plot of uncapped 6-meter copper composites
and Figure 17-8 shows the log probability plot of uncapped 6-meter
composites for the Blue Whale only
The estimation strategy for copper is similar to that for gold: 1)
capping of composite values; 2) a multi-pass estimation based on the
variogram nested structures; and, using ordinary kriging.
For the copper distributions, capping values were set for Zone 20 at
1.5 percent, Zone 21 at 0.8 percent, and Zone 22 at 1.0 percent.
Figures 17-9 through 17-11 show the computed correlograms for Zone 20
in the deposit orientations. The oxide saprolite Zone 21 only had 88
composites, and a correlogram in this zone alone could not be
computed. In the sulfide saprolite Zone 22, horizontal and vertical
correlograms (Figure 17-12) were computed.
FIGURE 17-3 Correlogram for Gold Zone 10-Strike
GRAPH NOT INCLUDED
FIGURE 17-4 Correlogram for Gold Zone 10 - Dip
GRAPH NOT INCLUDED
FIGURE 17-5 Correlogram for Gold Mineralized Envelope - Across Dip
GRAPH NOT INCLUDED
FIGURE 17-6 Correlogram for Blue Whale
GRAPH NOT INCLUDED
FIGURE 17-7 Log-Probability Plot of Uncapped 6m Composites for all Cu
GRAPH NOT INCLUDED
Item Cu Natural Logs
- --------------------------------------------------
Number 4307 Number 4307
Mean 0.227364 Mean -0.77374
Minimum 0.005 Minimum -2.30103
Maximum 1.4175 Maximum 0.151523
Variance 0.036015 Variance 0.120756
St. Dev. 0.189776 St. Dev. 0.347499
FIGURE 17-8 Log-Probability Plot for Blue Whale of Uncapped
6m Composites for Cu
GRAPH NOT INCLUDED
Item Cu Natural Logs
- --------------------------------------------------
Number 156 Number 156
Mean 2.784102 Mean 0.255018
Minimum 0.1825 Minimum -0.73874
Maximum 20.6051 Maximum 1.313975
Variance 9.697541 Variance 0.159999
St. Dev. 3.114087 St. Dev. 0.399999
FIGURE 17-9 Correlogram for Copper Zone 20 - Strike
GRAPH NOT INCLUDED
FIGURE 17-10 Correlogram for Copper Zone 20 - Dip
GRAPH NOT INCLUDED
FIGURE 17-11 Correlogram for Copper Zone 20 - Perpendicular to Dip
GRAPH NOT INCLUDED
FIGURE 17-12 Correlogram for Copper Zone 22
GRAPH NOT INCLUDED
17.5.3 Summary
- -------------------------------------------------------------------------------
Variograms were run on the drill hole data to evaluate the spatial
variability and lateral grade continuity through the deposit and
provide limits for the search radius used in the grade interpolation
process. Variograms for both Au and Cu downhole composites were
computed. Three-dimensional variograms were run for different
orientations including strike, dip, and across the ore zones (Table
17-5).
TABLE 17-5
Gold Reserve Inc.
Brisas Project, Venezuela
Feasibility Update
Variogram Models
Metal Zone Direction Azimuth Dip Nugget Sill 1 Range 1(m) Sill 2 Range 2(m)
- --------------------------------------------------------------------------------------------------------
Gold Mineral Envelope- Major 185 0 0.4484 0.3395 30.8 0.1647 130.1
Saprolite and Semi-Major 275 -35 0.4636 0.2433 28.2 0.2762 144.5
Hard Rock Minor 95 -55 0.5649 0.2399 21.1 0.1861 50.1
Blue Whale Average 185 -35 0.5703 0.2923 81.4 0.1964 126.2
Copper Mineral Envelope Major 185 0 0.1063 0.6563 45.3 0.2179 172.1
Hard Rock Semi-Major 275 -35 0.6460 0.1647 76.2 0.1469 156.4
Minor 95 -55 0.3744 0.3862 15.8 0.2856 54.1
Mineral Envelope
Saprolite Average 185 -90 0.3437 0.5590 41.5 0.1365 76.1
Gold and copper composite values were capped according to the
statistical review of the data in order to prevent outlying values from
unnecessarily influencing the model toward higher gold and copper values
(Table 17-6). PAH does not believe the composite grade capping will
have a great influence on the overall model but it could locally
prevent grade overestimation.
TABLE 17-6
Gold Reserve Inc.
Brisas Project, Venezuela
Feasibility Update
Capping Grades for 6M Downhole Composites
Metal Population Capping Grade # Comps Capped
- --------------------------------------------------------------------
Gold Mineral Envelope 8.5 gpt 44
Blue Whale 8.5 gpt 9
Copper Oxide Saprolite 0.8% 2
Sulfide Saprolite 1.0% 9
Hard Rock 1.5% 29
Blue Whale 1.5% 36
17.6 Grade Estimation and Validation
- -------------------------------------------------------------------------------
The gold and copper grade interpolations for the mineral envelopes only
used the 6-meter downhole composites that fell within the grade
envelopes. Only blocks within the grade envelopes received an Au or a
Cu grade. The ordinary kriging (OK) interpolation method was used for
all runs. Grade estimation parameters for Au and Cu are shown on
Tables 17-7 and 17-8 respectively.
TABLE 17-7
Gold Reserve Inc.
Brisas Project, Venezuela
Feasibility Update
Gold Grade Estimations Parameters
Min. Max. Max.
Search Direction Search Distance Comps Comps Comps
--------------------- -------------- Per Per Per
Zone Pass Y Azim Y dip X dip Y X Z block block hole Method
- -------------------------------------------------------------------------------------------------------
Within Gold 1 185 0 -35 30 30 20 3 8 2 OK
Mineral 2 185 0 -35 130 140 20 3 8 2 OK
Envelope 3 185 0 -35 130 140 20 1 8 OK
- -------------------------------------------------------------------------------------------------------
Blue 1 185 0 -35 100 50 12 3 8 2 OK
Whale 2 185 0 -35 100 50 12 1 8 OK
- -------------------------------------------------------------------------------------------------------
Outside Mineral Envelope 1 185 0 -35 130 140 20 1 8 OK
- -------------------------------------------------------------------------------------------------------
Outside Min. Env.
when Au>0.25 gpt 1 185 0 -35 20 20 10 1 8 OK
TABLE 17-8
Gold Reserve Inc.
Brisas Project, Venezuela
Feasibility Update
Copper Estimations Parameters
Min. Max. Max.
Search Direction Search Distance Comps Comps Comps
--------------------- -------------- Per Per Per
Zone Pass Y Azim Y dip X dip Y X Z block block hole Method
- -------------------------------------------------------------------------------------------------------
Within Copper 1 185 0 -35 45 75 15 3 8 2 OK
Mineral Envelope 2 185 0 -35 170 150 20 3 8 2 OK
Hard Rock 3 185 0 -35 170 150 20 1 8 OK
- -------------------------------------------------------------------------------------------------------
Blue 1 185 0 -35 100 50 12 3 8 2 OK
Whale 2 185 0 -35 100 50 12 1 8 OK
- -------------------------------------------------------------------------------------------------------
Within Copper 1 185 0 0 40 40 12 3 8 2 OK
Mineral Envelope 2 185 0 0 75 75 20 3 8 2 OK
Saprolite 3 185 0 0 75 75 20 1 8 OK
- -------------------------------------------------------------------------------------------------------
Outside Copper 1 185 0 -35 170 150 20 1 8 OK
Mineral Envelope
- -------------------------------------------------------------------------------------------------------
Outside Min. Env. 1 185 0 -35 20 20 10 1 8 OK
when Cu>0.08%
The local grade bias was checked by visually inspecting the block
grades against the nearby drill hole composite grades both on sections
and plans. The block grade distribution generally compares reasonably
well with the nearby composite values. Figures 17-13 and 17-14 are
cross sections showing the grade block model and drill hole composites
for Au and Cu, respectively.
Figure 17-13 Composites and Blocks Au Distribution - Section 682400N
DIAGRAM NOT INCLUDED
Figure 17-14 Composites and Blocks Cu Distribution - Section 682700N
DIAGRAM NOT INCLUDED
17.7 Resource Classification
- -------------------------------------------------------------------------------
Concurrently to the grade interpolation runs, a "distance model"
storing the distance to the nearest composite, and the "number of
composites used in the interpolation model" were constructed for every
block within the mineral envelopes. These models were used to classify
resources. A block located inside the mineral envelope, within 30
meters about the range of gold variogram first structure - on strike
and dip of the nearest sample point, and with at least five composites
(i.e., three drill holes) used in the interpolation, is considered
measured. The average distance for the measured category blocks is 18
meters. A block located inside the mineral envelopes and within 30 to
70 meters, about half the range of gold variogram second structure on
strike and dip of the nearest composite, and with at least three
composites (i.e., two drill holes) used in the interpolation, is
considered indicated. The average distance for the indicated category
blocks is 37 meters. Blocks located inside the envelopes farther than
70 meters but less than a full variogram range from a sample point,
and/or having less than three composites used in the interpolation, are
considered inferred (average distance is 90 meters).
Besides the measured, indicated, and inferred resources located within
the Au and Cu mineral envelopes, other inferred resources are
considered likely to exist outside the envelope. In order to quantify
this inferred resource, grade interpolation routines affecting only
blocks outside the envelopes were run for both Cu and Au. No
constraining mineral envelope was constructed. All composites were
allowed to participate in the interpolation. The search radii were
parallel to the main trends of the deposit as shown in Tables 17-7 and
17-8.
17.8 Resource Statement
- -------------------------------------------------------------------------------
Table 17-9 tabulates the measured, indicated, and inferred resources
and shows the tonnage/grade variability at various gold equivalent
cutoff grades. The gold equivalent grade states the total metal
content in terms of gold grade. This is done by calculating a copper
to gold ratio based on value. Gold equivalent calculations are based
on metal prices of $400/ounce Au, and $1.15/lb Cu, anticipated metal
recoveries, and freight, smelter and refining costs. A gold equivalent
of 1.16 grams per tonne per percent copper was calculated based on the
results of the economic analysis.
At a 0.4 AuEq cutoff grade the measured and indicated resource is 573.9
million tonnes at a gold grade of 0.66 gpt and a copper grade of 0.13
percent. In addition, the inferred resource is estimated as 114.9
million tonnes at 0.59 gpt Au grade and 0.12 percent copper grade at a
0.4 AuEq cutoff grade. The inferred resources include the inferred
mineralization both within and outside the mineral envelopes. This
resource estimate is inclusive of the reserve estimate.
The planned pit area is, for the most part, well covered by the
existing drilling that provides sufficient definition for the
establishment of measured and indicated resources. The deeper west
side of the pit, however, is limited by a large amount of inferred
resources along the downdip extension of the mineralized zone.
TABLE 17-9
Gold Reserve Inc.
Brisas Project, Venezuela
Feasibility Update
Mineral Resource Estimate
Gold Copper
AuEq ---------- ----------
Category Cutoff k tonnes gpt k ozs % M lbs
- ---------------------------------------------------------------------
0.3 285,405 0.634 5,817 0.114 717
0.4 250,565 0.686 5,527 0.119 657
Measured 0.5 207,448 0.755 5,034 0.126 576
0.6 165,410 0.834 4,437 0.135 492
0.7 129,741 0.918 3,830 0.144 412
0.3 391,430 0.565 7,110 0.126 1,087
0.4 323,371 0.637 6,621 0.13 927
Indicated 0.5 258,354 0.717 5,952 0.135 769
0.6 201,578 0.802 5,198 0.14 622
0.7 154,756 0.893 4,441 0.145 495
0.3 676,835 0.594 12,927 0.121 1,804
Measured 0.4 573,936 0.658 12,148 0.125 1,584
+ 0.5 465,802 0.734 10,986 0.131 1,345
Indicated 0.6 366,988 0.816 9,635 0.138 1,114
0.7 284,497 0.904 8,271 0.145 906
Note: AuEq based on the "Smelter Case". AuEq = Au (gpt) + Cu (%) * 1.16
Gold Copper
AuEq ---------- ----------
Category Cutoff k tonnes gpt k ozs % M lbs
- ---------------------------------------------------------------------
0.3 161,853 0.482 2,508 0.115 410
0.4 114,937 0.590 2,182 0.116 294
Inferred 0.5 84,319 0.691 1,873 0.116 216
0.6 60,928 0.801 1,569 0.112 150
0.7 45,770 0.896 1,319 0.111 112
Note: AuEq based on the "Smelter Case". AuEq = Au (gpt) + Cu (%) * 1.16
(*) Inferred resources include both within and outside the mineral envelopes.
17.9 Reserve Estimation
- -------------------------------------------------------------------------------
The Brisas Project is an open-pit gold-copper mining project, which
will utilize hydraulic shovels and 236-tonne trucks as the primary
mining equipment. Based on the results of optimization analysis, an
ultimate pit was designed. A production schedule was then developed
based on a target of 0.1 percent copper grade to produce a 24 percent
copper concentrate grade with a blend of the two hard-rock ores. This
schedule resulted in an average production rate of 25.2 million tonnes
of hard rock ore and on average 51.8 million tonnes of waste per year
over the 18.5 years of the project. During the first four years of the
project, 9.6 million tonnes of oxide saprolite ore and 13.1 million
tonnes of sulfide saprolite ore are mined. Saprolite material is
stockpiled separately. The sulfide saprolite is fed to the crusher at
a rate of 1.95 million tonnes per year (mtpy) for a nominal seven
years. Oxide saprolite is fed to the mill at a rate of 0.25 mtpy while
the sulfide saprolite is processed. When milling of sulfide saprolite
is completed, the oxide saprolite rate is increased to 0.70 mtpy.
Using this production schedule, capital and operating cost estimates
were developed for the project, including the mine and processing
plant. These estimates were then incorporated into an economic model
to determine the viability of the project based on metal prices of
US$400 per ounce for gold and US$1.15 per pound for copper.
Sensitivity analyses on metal prices, and capital and operating costs
were then conducted.
There are two hard rock ore types, which are referred to as North and
South. Although the names imply a geographic relationship, the two
ores are actually defined based on the copper content. North ore is a
gold-chalcopyrite-pyrite with a copper content greater than or equal to
0.05 percent. South ore is a gold-pyrite with a copper content less
than 0.05 percent. In general the ore types split at 681,800 North;
however, both occur on either side of this line.
17.9.1 Optimization Analysis
- -------------------------------------------------------------------------------
Design of the ultimate pit was based on the results of a Whittle
Lerchs-Grossmann shell analysis. Whittle is a software package that
uses the Lerchs-Grossmann algorithm to determine the approximate shape
of a near-optimal pit shell based on applied cutoff-grade criteria and
pit slopes. These shells are generated from the geologic grade models,
and economic and physical criteria. Whittle pit shells do not provide a
reserve estimate because roads and ramps are not incorporated and the
shapes produced may not be practical due to real world or physical
constraints.
This Whittle analysis was conducted in April 2005 and was based on the
results of the Feasibility Study. Results of this analysis were the
basis for the pit design on which the reserve statement in this report
is based. Subsequent to the Whittle analysis and pit design the
economics including metal prices used for the reserve were modified to
incorporate the latest estimates. These revised economic parameters
(US$400 per ounce for gold and US$1.15 per pound for copper) were used
for reserve estimation only. A brief Whittle analysis using these
revised economic parameters was conducted to see the impact. As
expected it produced a similar Whittle pit shell configuration. The
difference was not significant enough to justify developing new pit
designs, production schedules, and economics.
The April 2005 Whittle analysis was based on the economic and physical
parameters shown in Table 17-10 and the recovery information in Table
17-11. Blocks in the inferred resource category were treated as waste
and assigned a negative value equal to the mining cost. Pit shells
were allowed to cross the concession boundary to maximize the recovery
of metal on the Brisas Concession.
A range of shells were developed to determine the project's sensitivity
and the basis for the designed ultimate pit. As expected the tonnes
increased and the grade decreased as the metal prices increased because
increasing the metal price increases the revenue per tonne and thus the
tonnage available for milling.
TABLE 17-10
Gold Reserve Inc.
Brisas Project, Venezuela
Feasibility Update
Pit Optimization Parameters
Description Units Value
- ------------------------------------------------------------------------------
Metal Prices
Gold $/t oz 350.000
Copper $/lb 0.900
Production Tax/Royalty
- ------------------------------------------------------------------------------
Percentage of Au Sold Domestically % 33.33
Tax Rate on Gold Sold Domestically % 1.00
Tax Rate on Exported Gold From Saprolite Ore % 3.00
Tax Rate on Exported Gold From Hard Rock Ore % 2.33
Copper Tax Rate % 1.70
Operating Costs
- ------------------------------------------------------------------------------
Waste Mining Cost $/waste-tonne 0.46
Incremental Mining Cost
By Depth - Waste & Ore $/Bench (6 m) 0.012
Oxide Saprolite Ore Mining Cost $/ore-tonne 0.71
Ore Mining $/ore-tonne 0.46
Milling $/ore-tonne 2.21
G&A $/ore-tonne 0.39
Reclamation - Facilities,
Waste Dumps, Tailings $/tonne-ore 0.035
Total Ore Operating Cost $/tonne-ore 3.10
Total Ore Operating Costs Excluding Mining $/tonne-ore 2.64
Smelting & Refining Related Charges
- ------------------------------------------------------------------------------
Gold Deduct from Concentrate % 1.00
Copper Deduct from Concentrate % 1.00
Smelter Recovery - Gold Dore % 99.90
Smelter Recovery - Gold From Concentrate % 99.90
Gold in Concentrate Grade - Saprolite g/t 89.20
Gold in Concentrate Grade - Hard Rock g/t 89.20
Copper Concentrate Grade - Saprolite % 24.00
Copper Concentrate Grade - Hard Rock % 24.00
Concentrate Transportation Cost $/tonne conc 78.32
Smelting Cost $/tonne conc 77.79
Copper Refining Cost $/lb payable Cu 0.078
Gold Refining - Dore $/payable oz Au 6.00
Physical Parameters
- ------------------------------------------------------------------------------
Oxide Saprolite Density tonnes/m3 1.44
Sulfide Saprolite Density tonnes/m3 1.68
Southern Hard Rock Density tonnes/m3 2.84
Northern Hard Rock Density tonnes/m3 2.86
Saprolite Overall Pit Slopes By Sector with North set to 0
- ------------------------------------------------------------------------------
Sector 0 - 33 degrees 19.1
Sector 33 - 71 degrees 31.2
Sector 71 - 127 degrees 25.7
Sector 127 - 187 degrees 23.0
Sector 187 - 266 degrees 38.0
Sector 266 - 333 degrees 32.7
Sector 333 - 0 degrees 19.1
Hard Rock Overall Pit Slopes By Sector with North set to 0
- ------------------------------------------------------------------------------
Sector 0 - 71 degrees 50.6
Sector 71 - 127 degrees 31.7
Sector 127 - 187 degrees 46.7
Sector 187 - 0 degrees 50.6
TABLE 17-11
Gold Reserve Inc.
Brisas Project, Venezuela
Feasibility Update
Metal Recoveries
Gold Recovery Input Parameters
Mill Feed Grade
-------------------------- Mill Smelter
Ore Type Units Minimum Maximum Recovery Pay For Payable
- -------------------------------------------------------------------------
Oxide Saprolite Ore
- ----------------------
g/t 0.001 0.051 10.00% 99.82% 9.98%
g/t 0.052 0.100 75.00% 99.82% 74.87%
g/t 0.101 0.500 88.00% 99.82% 87.85%
g/t 0.501 0.690 90.00% 99.82% 89.84%
g/t 0.691 0.990 91.00% 99.82% 90.84%
g/t 0.991 1,000.000 92.00% 99.82% 91.84%
Sulfide Saprolite Ore
- ----------------------
g/t 0.001 0.500 55.00% 98.80% 54.34%
g/t 0.501 0.590 63.00% 98.80% 62.24%
g/t 0.591 0.690 68.00% 98.80% 67.18%
g/t 0.691 0.790 73.00% 98.80% 72.12%
g/t 0.791 0.890 76.00% 98.80% 75.09%
g/t 0.891 0.990 78.00% 98.80% 77.06%
g/t 0.991 1,000.000 80.00% 98.80% 79.04%
Hard Rock Ore w/ Cu North
- ----------------------
g/t 0.001 0.500 70.00% 98.48% 68.93%
g/t 0.501 0.590 76.00% 98.48% 74.84%
g/t 0.591 0.690 78.00% 98.48% 76.81%
g/t 0.691 0.790 80.00% 98.48% 78.78%
g/t 0.791 0.890 83.00% 98.48% 81.73%
g/t 0.891 0.990 89.00% 98.48% 87.64%
g/t 0.991 1,000.000 90.00% 98.48% 88.63%
Hard Rock Ore w/o Cu South
- ----------------------
g/t 0.001 0.500 60.00% 98.48% 59.09%
g/t 0.501 0.590 68.00% 98.48% 66.96%
g/t 0.591 0.690 72.00% 98.48% 70.90%
g/t 0.691 0.790 75.00% 98.48% 73.86%
g/t 0.791 0.890 79.00% 98.48% 77.80%
g/t 0.891 0.990 85.00% 98.48% 83.70%
g/t 0.991 1,000.000 90.00% 98.48% 88.63%
Copper Recovery Input Parameters
Mill Feed Grade
-------------------------- Mill Smelter
Ore Type Units Minimum Maximum Recovery Pay For Payable
- -------------------------------------------------------------------------
Oxide Saprolite Ore
- ----------------------
% 0.001 0.050 0.00% 0.00% 0.00%
% 0.051 0.075 0.00% 0.00% 0.00%
% 0.076 0.125 0.00% 0.00% 0.00%
% 0.126 0.175 0.00% 0.00% 0.00%
% 0.176 0.250 0.00% 0.00% 0.00%
% 0.251 0.500 0.00% 0.00% 0.00%
% 0.501 100.000 0.00% 0.00% 0.00%
Sulfide Saprolite Ore
- ----------------------
% 0.001 0.050 10.00% 95.83% 9.58%
% 0.051 0.075 42.00% 95.83% 40.25%
% 0.076 0.125 50.00% 95.83% 47.92%
% 0.126 0.175 58.00% 95.83% 55.58%
% 0.176 0.250 66.00% 95.83% 63.25%
% 0.251 0.500 80.00% 95.83% 76.67%
% 0.501 100.000 85.00% 95.83% 81.46%
Hard Rock Ore - North
- ----------------------
% 0.001 0.020 40.00% 95.83% 38.33%
% 0.021 0.035 55.00% 95.83% 52.71%
% 0.036 0.060 68.00% 95.83% 65.17%
% 0.061 0.110 70.00% 95.83% 67.08%
% 0.111 0.140 79.00% 95.83% 75.71%
% 0.141 0.200 82.60% 95.83% 79.16%
% 0.201 0.400 86.20% 95.83% 82.61%
% 0.401 1.000 93.00% 95.83% 89.13%
% 1.001 100.000 93.50% 95.83% 89.60%
Hard Rock Ore - South
- ----------------------
% 0.001 0.020 40.00% 95.83% 38.33%
% 0.021 0.035 55.00% 95.83% 52.71%
% 0.036 0.060 68.00% 95.83% 65.17%
% 0.061 0.110 70.00% 95.83% 67.08%
% 0.111 0.140 79.00% 95.83% 75.71%
% 0.141 0.200 82.60% 95.83% 79.16%
% 0.201 0.400 86.20% 95.83% 82.61%
% 0.401 1.000 93.00% 95.83% 89.13%
% 1.001 100.000 93.50% 95.83% 89.60%
17.9.2 Mine Design
- -------------------------------------------------------------------------------
In general the same pit design parameters were used as in the
Feasibility Study with the pit slopes being the only significant
change. A bench height of 6 meters was used in the saprolite and
weathered rock and 12 meters was used in the hard rock. Haul roads
were incorporated into the pit design using a 35-meter width for
two-lane roads and a 20-meter width for single-lane roads. Road grades
were maintained at 10 percent in most of the pit; however, they were
decreased to 8 percent in the saprolite and increased to 12 percent in
the bottom of the pit. Overall the pit design shown in Figure 17-15,
which is the basis for the reserve estimate, is similar to the
Feasibility Study, with the most noticeable difference being a further
push to the west side and a change to a two-lane road from a
single-lane road in the west wall of the pit. This was done to shorten
the haulage distance to dumps on the west side of the pit and to allow
better access to the west side of the pit so that waste stripping could
be deferred.
Pit slopes were modified from the Feasibility Study based on a
preliminary review by GRI and BGC of the geotechnical parameters in
relationship to the Feasibility Study ultimate pit design and some of
the information acquired as part of the Feasibility Study. This review
resulted in a simplification of the pit slope configuration. Two pit
slope sectors were defined for use in the saprolite and weathered rock
and two others were defined for the hard rock. Figures 17-15 and 17-16
show the design sectors and inter-ramp slope angles for the saprolite
and hard rock, respectively. A face angle of 70 degrees was assumed in
all the sectors and for all the rock types. Inter-ramp pit slopes were
controlled by varying the catch-bench width.
Dumps designs were revised from the Feasibility Study designs. The
same design parameters were used but the dump was split into a North
and South dump. In the Feasibility Study the plan was to divert the
river around the dump. Subsequent to the Feasibility Study the
decision was made by GRI to split the dump rather than divert the
river. A river crossing has been included in the plan to access the
South dump. Currently, this crossing is envisioned as a set of
culverts with a rock cover. Figure 17-17 shows the revised mine layout
with the ultimate pit and waste dump designs.
Figure 17-15 Saprolite and Weathered Hard Rock Slope Sectors
DIAGRAM NOT INCLUDED
Figure 17-16 Fresh Rock Slope Sectors
DIAGRAM NOT INCLUDED
Figure 17-17 Overall Project Layout
DIAGRAM NOT INCLUDED
17.9.3 Cutoff Grade
- -------------------------------------------------------------------------------
Since the Brisas Project has two metals, gold and copper, a cutoff
grade based on a single metal does not account for the value provided
by the other metal. As a result, either an equivalent metal cutoff
grade, such as the equivalent gold cutoff used in the resource report,
or a revenue cutoff has to be used. For reserve reporting, a revenue
cutoff grade of $3.04 per tonne for hard rock and $3.24 per tonne for
saprolite was used, since it is more straightforward than an equivalent
metal cutoff grade. This approach is consistent with previous reporting
practices for this project. Table 17-12 shows the parameters used to
develop the revenue cutoff.
Table 17-12
Gold Reserve Inc.
Brisas Project, Venezuela
Feasibility Update
Revenue per Tonne Cutoff Grade Calculation Parameters
Description Units Value
- ---------------------------------------------------------------
Milling Costs $/ore-tonne 2.54
G&A Costs $/ore-tonne 0.42
Incremental Reclamation Costs $/ore-tonne 0.08
Ore Operating Costs Excluding Mining $/ore-tonne 3.04
Saprolite Rehandle Costs $/ore-tonne 0.20
Hard Rock Revenue per Tonne Cutoff Grade $/ore-tonne 3.04
Saprolite Revenue per Tonne Cutoff Grade $/ore-tonne 3.24
In order to report the tonnages in the ultimate pit based on a revenue
cutoff, a revenue per tonne block model was developed. As part of this
process, mill gold and copper recoveries were generated for the block
model. Recoveries were assigned by rock type using the values in Table
17-11 except for oxide saprolite where the values in Table 17-11 were
reduced by 20 percent. Oxide saprolite recoveries were reduced with
the change in the process flowsheet to mill the material with the hard
rock as opposed to the Feasibility Study which fed the oxide saprolite
directly to the cyanidation circuit.
Using the mill recoveries and the economic parameters in Table 17-13, a
revenue per tonne block model was developed for reserve reporting. To
determine the total revenue per tonne the value from gold and copper
were added together. Metal values were calculated by multiplying the
metal grade by the mill recovery and smelter recovery. Selling costs
are per-unit of metal costs that are incurred by the project after the
product leaves the mill including freight, smelting, refining, and
royalties.
Table 17-13
Gold Reserve Inc.
Brisas Project, Venezuela
Feasibility Update
Parameters for Revenue Model & Gold Equivalent Ratio
Parameter Units Value
- -----------------------------------------------------------------
Gold Price $/t. oz 400.00
Copper Price $/lb 1.15
Gold Freight, Smelting, Refining $/t. oz 5.08
Copper Freight, Smelting, Refining $/lb 0.43
Mill Recovery % See Table 17-11
Payable Gold % 98.76
Payable Copper % 95.88
Gold Production Tax % 3.00
Copper Production Tax % 1.44
Au Equivalent Ratio 1.16
The economic parameters used for the revenue model were derived from
the economic model for the project based on the latest operating plans
for the project. These parameters are different from those used in the
optimization analysis because the optimization was done in early 2005
and the revised parameters reflect the work that has been completed
since that time.
17.10 Reserve Statement
- -------------------------------------------------------------------------------
A reserve estimate based on metal prices of $400 per ounce for gold and
$1.15 per pound for copper was developed. Using a revenue cutoff of
US$3.04 per tonne for hard rock and $3.24 in saprolite produces a
proven and probable reserve of 484.6 million tonnes of ore at a gold
grade of 0.67 grams per tonne and a copper grade of 0.13 percent.
Table 17-14 shows the Brisas Project reserves by category.
PAH believes that the reserve estimate shown in Table 17-14 is
reasonable and meets the CIM standards for a reserve estimate based on
CIM Standards of Mineral Resources and Reserves Definitions and
Guidelines adopted by the Canadian Institute of Mining (CIM) Council on
December 11, 2005.
Table 17-14
Gold Reserve Inc.
Brisas Project, Venezuela
Feasibility Update
Reserve Estimate Based on Revenue Cutoffs of $3.04 for Hard Rock & $3.24
for Saprolite
Au Au Au Cu Cu
Reserve Tonnage Grade grams ounces Grade Cu M
Category (000's) g/t (000's) (000's) percent tonnes pounds
- ------------------------------------------------------------------------
Proven 226,252 0.69 156,517 5,032 0.12 272,376 600
Probable 258,398 0.64 166,628 5,357 0.13 334,397 737
Total Ore 484,649 0.67 323,145 10,389 0.13 606,773 1,338
- ------------------------------------------------------------------------
Waste 952,304 Strip Ratio 1.96
Total In-Pit 1,436,953
Note: Revenue is based on metal prices of $400/oz for gold & $1.15/lb
for Copper.
The reserve estimate in Table 17-14 is based on the assumption that the
pit backslope extends onto the Las Cristinas Concession, which will
require a backslope agreement. GRI received approval of its operating
plan from MEM in February 2003, which included the extension of the
backslope onto the Las Cristinas Concession. Also in October 2006, GRI
and Crystallex International Corporation (Crystallex) proposed to MARN
to move a water diversion channel on the southern part of the Las
Cristinas Concession, further northward, away from the Brisas pit.
This proposal, if approved, should allow GRI to formalize a backslope
agreement. Crystallex has been granted an operations contract to the
adjacent Las Cristinas property (see section 15.0 Adjacent Properties).
PAH has not reviewed the GRI MEM approved 2003 operating plan or
Crytallex's proposed diversion channel. According to GRI, Corporacion
Venezolana de Guyana (CVG) and MIBAM has indicated to GRI that a
backslope agreement is probable. PAH believes that the backslope
assumption is valid because backslope agreements are a common practice
in the mining industry and the government agencies have been favorable
toward an agreement. Also, the backslope agreement would allow Las
Cristinas/CVG to mine onto the Brisas Concession in the event its mine
plan reaches the border area first. Discussions with MIBAM/CVG are
ongoing. In the event an agreement is not reached, the reserve
estimate will have to be reduced significantly.
17.11 Summary and Conclusions
- -------------------------------------------------------------------------------
17.11.1 Adequacy of Procedures
- -------------------------------------------------------------------------------
PAH and various other firms and independent consultants have reviewed
the methods and procedures utilized by GRI at the Brisas Project to
gather geologic, geotechnical and assaying information and found them
reasonable and meeting generally accepted industry standards for a
feasibility level of study.
17.11.2 Adequacy of Data
- -------------------------------------------------------------------------------
PAH believes that the Brisas Project has conducted exploration and
development sampling and analysis programs using standard practices,
providing generally reasonable results. PAH believes that the
resulting data can effectively be used in the subsequent estimation of
resources and reserves.
17.11.3 Compliance with Canadian NI 43-101 Standards
- -------------------------------------------------------------------------------
PAH believes that the current drill hole database is sufficient for
generating a feasibility level resource model for use in resource and
reserve estimation. Recovery and cost estimates are based upon
sufficient data and engineering to support a reserve statement.
Economic analysis using these estimates generates a positive cash flow,
which supports a reserve statement.
PAH believes that the resource and reserve estimates included in this
report conform to international standards such as the CIM definitions
as adopted by Canadian National Instrument NI 43-101.
17.11.4 Exploration Potential
- -------------------------------------------------------------------------------
The Brisas deposit is still open along the downdip direction and the
resource is mostly limited by drilling. Exploration potential on the
Brisas Project also exists to the south and southeast of the proposed
pit where several narrow intercepts of medium- to high-grade gold
mineralization have been encountered by drilling. Some of these
intercepts are near the surface.
18.0 OTHER RELEVANT DATA AND INFORMATION
- -------------------------------------------------------------------------------
PAH is not aware of any other relevant data or information that should
be included in this Technical Report.
19.0 INTERPRETATION AND CONCLUSIONS
- -------------------------------------------------------------------------------
19.1 Adequacy of Procedures
- -------------------------------------------------------------------------------
PAH and various other firms and independent consultants have reviewed
the methods and procedures utilized by GRI at the Brisas Project to
gather geological, geotechnical, and assaying information and found
them reasonable and meeting generally accepted industry standards for a
bankable feasibility level of study.
19.2 Adequacy of Data
- -------------------------------------------------------------------------------
PAH believes that the Brisas Project has conducted exploration and
development sampling and analysis programs using standard practices,
providing generally reasonable results. PAH believes that the
resulting data can effectively be used in the subsequent estimation of
resources and reserves.
19.3 Adequacy of Feasibility Study
- -------------------------------------------------------------------------------
This Technical Report is based on the Brisas Project Feasibility Study
prepared by Aker Kvaerner Metals Inc., dated January 2005, the
Supplement to the Feasibility Study prepared by PAH dated November
2005, the Project Scope and Definition Document prepared by SNC
Lavalin, dated April 2006, and the Las Brisas Project Resource and
Reserve Update prepared by Marston, dated October 2006. PAH believes
that this Feasibility Study and the supporting documents were prepared
using standard industry practices and provides reasonable results and
conclusions.
19.4 Compliance with Canadian NI 43-101 Standards
- -------------------------------------------------------------------------------
PAH believes that the current drill hole database is sufficient for
generating a feasibility level resource model for use in resource and
reserve estimation. Recovery and cost estimates are based upon
sufficient data and engineering to support a reserve statement.
Economic analysis using these estimates generates a positive cash flow,
which supports a reserve statement.
At a 0.4 gpt AuEq cutoff grade the measured and indicated resource is
573.9 million tonnes at a gold grade of 0.66 gpt and a copper grade of
0.13 percent. Included in this resource is a proven and probable
reserve of 484.6 million tonnes of ore at a gold grade of 0.67 gpt and
a copper grade of 0.13 percent based on a value cutoff of US$3.04 per
tonne for hard rock and $3.24 for saprolite.
PAH believes that the resource and reserve estimates have been
calculated utilizing acceptable estimation methodologies. PAH is also
of the opinion that the classification of measured and indicated
resources, stated in Table 17-9, and proven and probable reserves,
stated in Table 17-14, meet the definitions as stated by Standards for
Disclosure for Mineral Projects, Form 43-101F1 and Companion Policy
43-101CP dated December 23, 2005.
20.0 RECOMMENDATIONS
- -------------------------------------------------------------------------------
The Brisas Project Feasibility Study dated January 2005 provides
reasonable results and conclusions and, in PAH's opinion, meets the
requirements of a Feasibility Study. This Technical Report is based on
the Feasibility Study, the Supplement to the Feasibility Study prepared
by PAH dated November 2005, the Project Scope and Definition Document
prepared by SNC Lavalin, dated April 2006, and the Brisas Project
Resource and Reserve Update prepared by Marston, dated October 2006.
As the project has moved from the feasibility stage into the design and
construction phase additional information has been gathered. As the
project continues to move forward, there are areas of the project that
should be given additional consideration. Below is a list of
recommendations to consider:
PAH recommends additional geotechnical studies to evaluate steepening
the pit slopes. At the present time Vector Colorado LLC., is
completing a detailed study of pit slope stability. Six oriented core
holes have been drilled. An acoustic televiewer has been used on four
of the holes to demonstrate fracture orientation. A report is in
progress and will be finalized in the 4th Quarter of 2006. Estimated
cost to complete the work is $50,000.
PAH recommends additional testwork on the oxide saprolite ores to see
if there is any detrimental effect on the sulfide ore flotation by
adding the oxide ores to the flotation circuit PAH recommends
conducting bench-scale batch grinding and flotation tests with the
following ore blends:
Test 1 Test 2
- -------------------------------------------------------------------
Hard Rock, North ore 50% 51%
Hard Rock, South ore 41% 42%
Sulfide saprolite 6% 7%
Oxide saprolite 3% 0%
PAH estimates these tests would cost $20,000.
PAH recommends a geochemical assessment of the potentially
acid-generating material in the waste rock piles to determine long-term
treatment options. Studies thus far show that the overall material has
a net neutralizing potential, and 250 additional ABA tests have been
conducted. A geochemical model is being developed to address the
makeup of the surface and ground waters over the life of the project.
Vector is currently undertaking a geochemical model to look at
long-term chemistry of the waste rock piles. PAH estimates that this
work will cost an additional $25,000.
21.0 REFERENCES
- -------------------------------------------------------------------------------
1) J.E. MinCorp, a division of Jacobs Engineering Group, Inc., February
1988, Las Brisas Pre-Feasibility Study.
2) BGC Engineer Inc., April 29, 1999, Brisas Del Cuyuni Project Review of
250 Million Tonne Pre-Feasibility Open Pit .
3) Aker Kvaerner Metals Inc., January 2005, Las Brisas Project Feasibility
Study.
4) SGS Lakefield Research Limited, February 1, 2005, An Investigation of
Copper and Gold Recovery from Las Brisas Samples.
5) Pincock Allen & Holt, November 2005, Supplement to the January 2005
Brisas Feasibility Study.
6) Vector Colorado, LLC, December 2005, Hydrology and Pit Dewatering
Addendum 1.
7) AATA International, December 2005, Environmental and Social Impact
Assessment, Final Draft Version 1.03.
8) SNC Lavalin, April 2006, Project Scope & Definition Document.
9) Marston & Marston, Inc., October 2006, Brisas Project Resource &
Reserve Update.
22.0 ADDITIONAL REQUIREMENTS FOR DEVELOPMENT PROPERTIES
- -------------------------------------------------------------------------------
This section provides additional information on the planned mine and
process plant operation. Additionally, it provides information on the
capital and operating costs as well as the over all project economics.
22.1 Mining Operations
- -------------------------------------------------------------------------------
The Brisas Project is an open-pit gold-copper mining project, which
will utilize hydraulic shovels and 236-tonne trucks as the primary
mining equipment. Production is scheduled for 25.2 million tonnes of
hard rock ore and on average 51.8 million tonnes of waste per year over
the 18.5 years of the project. During the first four years of the
project 9.6 million tonnes of oxide saprolite ore and 13.1 million
tonnes of sulfide saprolite ore will be mined. The saprolite material
is stockpiled separately. Sulfide saprolite is fed to the crusher at a
rate of 1.95 mtpy for a nominal seven years. Oxide saprolite is fed to
the crusher at a rate of 0.25 mtpy while the sulfide saprolite is
processed. When milling of sulfide saprolite is completed, the oxide
saprolite rate is increased to 0.70 mtpy.
Total reserves are estimated at 484.6 million tonnes of ore at a gold
grade of 0.67 grams per tonne and a copper grade of 0.13 percent with a
strip ratio of 1.96 tonnes of waste per tonne of ore. Reserves are
based on $400/oz gold price and $1.15/lb copper price.
There are two hard rock ore types, which are referred to as north and
south. Although the names imply a geographic relationship the two ores
are actually defined based on the copper content. North ore is a
gold-chalcopyrite-pyrite with a copper content greater than or equal to
0.05 percent. South ore is a gold-pyrite with a copper content less
than 0.05 percent. In general the ore types split at 681,800 North;
however, both occur on either side of this line.
Development of the mine production schedule was based on targeting a
0.1 percent average copper grade to produce a 24 percent copper
concentrate grade with a blend of the two hard rock ores. Overall the
split between these two ore types is 57 percent northern hard rock and
43 percent southern hard rock. Because of this split the production
target was to have at least 50 percent northern hard rock.
Both of the saprolite ores will be stockpiled since they have to be
mined at a rate that exceeds their milling rate in order to meet the
hard rock ore production requirements. Oxide saprolite mining will be
completed in Year 3 but milling will not begin until Year 2 and will be
completed in Year 19. Mining of sulfide saprolite ore ends in Year 6
but milling will not be completed until Year 7. Plans are for the hard
rock to be dumped directly into the primary crusher, near the pit exit
on the east side, to minimize stockpiling and rehandling.
All of the waste rock, except that used for tailings dam construction,
will be disposed of in the waste rock dumps located to the west of the
pit. There is the potential for the waste rock dumps to be located
over the down-dip extension of the existing ore body. However,
stripping requirements would likely prevent the pit from economically
expanding into the waste disposal area.
Plans are for the Brisas mine to operate two 12-hour shifts per day, 7
days per week for a total of 14 shifts per week. The mine operation
schedule allows for 26 shifts per year being lost due to weather delays
in the mine. It is envisioned that mining of ore would occur on both
shifts in order to minimize stockpiling and rehandling. Scheduled work
time is 10.5 hours per shift, that allows 30 minutes for meals, 30
minutes of delays, and 30 minutes lost during shift change.
Mine equipment requirements were developed from the annual mine
production schedule, based on the mine operation schedule, equipment
availability, and equipment productivities. The mine equipment fleet
will include 30m3 hydraulic shovels, 18m3 wheel loaders, 236-tonne
class haul trucks, and 251mm diameter track-mounted rotary drills.
Mine personnel includes all the exempt and non-exempt people working in
the mine operations, maintenance, engineering, and geology
departments. This includes the Mine Manager position. The General
Manager is included in the Project overhead costs.
Salary staff requirements have been estimated for mine operations,
maintenance, engineering, and geology personnel. A mine work schedule
of two shifts per day and seven days per week was used requiring four
work crews with a shift supervisor assigned to each crew. The salaried
mine staff includes a maximum of 75 people during mine production with a
maximum of eight expatriates. Expatriates are replaced over time with a
reduction to 4 by Year 2 and down to 1 from Year 3 through Year 16.
22.2 Recoverability
- -------------------------------------------------------------------------------
The final ore milling and copper and gold recovery processes used as
the basis for the Feasibility Study were developed by way of an
extensive metallurgical testing program. The initial phase of
metallurgical testing was conducted prior to 1998 and was used to
support a Pre-Feasibility Study prepared by JE MinCorp and issued in
February 1998. As part of the metallurgical test program for the
Pre-Feasibility Study, heap leaching of the ore was investigated as a
preferred processing route. The test work demonstrated that heap
leaching was not a viable alternative for recovering precious metals
due to high cyanide consumption and low gold recovery. High cyanide
consumption was caused by cyanide soluble copper in the ore and low
gold recovery was due to the very finely disseminated nature of the
gold within the ore.
From 1999 through 2004, a significant amount of metallurgical testing
ensued. Metallurgical testing was completed using both core samples
and a bulk ore sample. The test work included bench scale testing on
core samples and a portion of the bulk ore sample, and pilot plant
testing using the bulk ore sample. The focus of the metallurgical
testing included the following:
Defining the grinding and flotation characteristics of the different
ore types and ore blends.
Cyanide leaching characteristics of the 1st cleaner flotation tailing
for recovery of additional gold.
Optimization of the flotation process.
Mineralogy of the four primary ore types and various flotation products.
Mineralogy of final tailings.
Metallurgical testing to support trade-off studies of alternative
processing routes for both ores and concentrates.
Detailed chemical analysis of concentrates and final tailings to
support environmental studies and smelting inquiries.
Physical testing of ores, concentrates and tailings to support the
engineering activities relevant to the completion of the Feasibility
Study.
Three distinct test programs were pursued with respect to developing a
concentrator flowsheet: a grinding study, bench scale grinding and
flotation studies and cyanide leach testing, and pilot scale operation
of the selected process. A.R. MacPherson Consultants Ltd. conducted
tests to determine the size reduction characteristics of the various
ore types. Grinding tests included determination of crushing work
indices, autogenous mill work indices, Bond rod and ball mill work
indices and abrasion indices. The data developed from the grinding
tests was used along with the J.K SimMet grinding circuit simulation
software to select the grinding mill circuit configuration and predict
the power consumption of the grinding mills.
The latest in-depth flotation test work was conducted primarily by SGS
Lakefield Research in Lakefield, Ontario, Canada. The bulk of the
metallurgical testing was completed on core samples collected from
various sections of the ore body and representing the four major ore
types. Bench scale testing was used to determine basic flotation
characteristics and reagent scheme for the four ore types.
Previous plans had been to separately feed the oxide saprolite to the
cyanide leach circuit, bypassing flotation. Although doing so is
expected to result in 20 percent higher gold recovery than feeding it
to flotation, it incurs higher capital and operating costs. A tradeoff
study determined that feeding the oxide saprolite to flotation was the
better alternative, despite the lower recovery. However, it is
possible that blending the oxide saprolite with the other ore types may
adversely affect the flotation response of the other ores types, though
this would be minimized by spreading the addition of oxide saprolite
out over the life of the mine. Still, PAH recommends testing the
flotation reaction of the oxide saprolite to determine the effect using
the same ratio of ore types as planned for the operation. Should the
processing of oxide saprolite with the other ore types prove
problematical, it could be eliminated with little effect on production.
Sulfide saprolite has recoverable amounts of copper minerals which
makes direct leaching of the sulfide saprolite problematic. Test work
indicated that introduction of sulfide saprolite at about 8 percent of
the total feed (5,400 tonnes per day) does not harm the flotation
circuits.
Test work indicated that a mill feed grade equal to or greater than
0.10 percent copper was required to reliably produce a marketable
concentrate. To maintain a minimum copper grade of 0.10 percent in the
mill feed a blend of ores from the copper rich northern section of the
mine and the copper poor southern section of the ore body was required
to maintain the minimum copper grade throughout the life of the
project. Concentrate grades are estimated to be 24 percent copper.
Bench scale locked cycle tests were conducted to help determine final
flotation kinetics and circulating loads. Triplicate locked cycle
tests were also conducted to test the robustness and reproducibility of
the final process flowsheet. The locked cycle tests were successful in
confirming the process design and the data was used to finalize the
details of the Feasibility Study and subsequent Project Scope &
Definition Document process design criteria.
22.3 Markets and Contracts
- -------------------------------------------------------------------------------
Gold and copper markets are mature global markets with reputable
smelters and refiners located throughout the world. Market prices for
gold are over $500.00 per troy ounce. Copper prices are above $3.00
per pound.
Operations at the Brisas Project are expected to produce an annual
average of 119,000 tonnes per year of copper concentrate, containing 63
million pounds of copper, and 343,000 ounces of gold. A further 123,000
ounces per year of gold will be produced in the form of gravity
concentrates and dor.
A 20,000 metric tonne concentrate storage and ship loading facility
will be constructed in Puerto Ordaz. Copper concentrate will be trucked
to this facility for ocean shipment to a smelter, probably in Europe,
Japan or Southeast Asia.
Gravity concentrates and dor will be sold in Venezuela or shipped to
the United States, Canada or Europe for refining by one of the
internationally-established refiners.
Since the project is in the development stage and actual production
will not begin for over two years, contracts are in negotiation for
gold and copper sales.
22.4 Environmental Considerations
- -------------------------------------------------------------------------------
The Feasibility includes a plan for reclamation and closure. The
objectives, criteria and conceptual plans proposed in the Reclamation
and Closure Plan will be the subject of future mine management and
planning and as such, subject to continuing refinement. The Plan is
designed to provide practical onsite guidance for the implementation of
the principles outlined and will undergo regular review as appropriate
and necessary to update the Plan.
A complete Environmental and Social Impact Assessment (ESIA) program
has been conducted according to the laws of Venezuela to satisfy the
requirements of the Ministry of Environment and Natural Resources
(MARN) and an international ESIA program is being conducted according
to the guidelines of the World Bank Group (International Finance
Corporation-IFC) and the Equator Principles. The Venezuelan ESIA was
submitted to the Venezuelan government in July 2005. The international
ESIA is nearing completion and will be submitted to the financial
institutions to satisfy all requirements outlined in these assessments.
There are a number of significant remediation and reclamation
components within the existing plan including:
Closure and reclamation of the tailings storage facilities.
Closure and reclamation of the open pit area.
Closure and reclamation of the waste rock stockpile.
Closure and reclamation of the sediment ponds.
Closure and reclamation of the access and haul road between the crusher
site and the tailings facility.
Venezuelan Mining Regulations require that all buildings, facilities
and equipment owned by GRI at the time of abandonment be turned over to
the State. All the facilities will be left intact in anticipation of
annexation to the local community for continued beneficial use.
Closure and reclamation costs are currently estimated by SNC at $36.44
million.
22.5 Taxes
- -------------------------------------------------------------------------------
The principal taxes levied in Venezuela are:
a general income tax (lSLR) levied on both legal entities and
individuals.
a value added tax (IVA) levied up to the consumer level;
various taxes including exploitation taxes imposed on mining related
activities.
22.5.1 Income Tax
- -------------------------------------------------------------------------------
The law sets up three tax tables or tariffs. Tariff 2 is applicable to
stock corporations, (such as GRIs Venezuelan operation) limited
liability companies, partnerships limited by shares, associations,
establishments, corporations, legal and economic entities not
specifically mentioned by the law, and foreign companies and
corporations of any kind. The maximum Tariff 2 tax rate is 34
percent. There are no surcharges or surtaxes imposed as such on
corporate income. Likewise, there are no excess profit taxes.
Operating losses may be carried forward for three years to be offset
against taxable profits. For the economic model an income tax rate of
34 percent was applied.
22.5.2 Value Added Tax
- -------------------------------------------------------------------------------
Impuestos Valor Agregado or value-added tax (VAT), a general sales tax,
is levied on the value added in respect of taxable supplies of goods and
services as well as in respect of the import of goods and services into
Venezuela. Historically there have been two mechanisms provided by law
to minimize or eliminate the companys exposure to VAT. The first, "VAT
Recovery", provides for the recovery of VAT paid via a credit from the
Republic. The second is, "VAT Exoneration", which provides for a
complete exoneration of VAT on imported items. Recently the President
of Venezuela announced that he planned to exempt certain capital assets
and goods not produced in country from VAT and import taxes.
Notwithstanding obtaining an exemption or exoneration of VAT on
imported items, domestic purchases will continue to be subject to VAT
and thereafter the recovery program. The current VAT rate, as of
January 2006, was 14 percent.
The Company expects to make
application to SENIAT for the VAT Tax recovery system in the event the
recent announcement by the President of Venezuela is not implemented.
The Company expects to be approved to participate in the recovery
system. As it is unclear when, and if a VAT tax exoneration will be
obtained or if the Presidents plans are implemented, the VAT tax on
domestic and external purchases is included in the economic model under
the recovery system.
22.5.3 Resource Taxes
- -------------------------------------------------------------------------------
The Brisas Project is subject to the following exploitation tax, which
is included in the financial model:
One percent of the commercial value in Caracas of refined gold and
silver sold in country,
Three percent of the commercial value in Caracas of refined gold and
silver exported (saprolite concession),
Four percent of the commercial value in Caracas of refined gold and
silver exported (hardrock concession),
Seven percent mine-mouth tax on production of copper (net of operating
costs).
22.5.4 Customs Duties
- -------------------------------------------------------------------------------
Venezuela is a member of the Andean Community and uses the Andean
Community customs tariff. The duty is an ad valorem duty calculated on
the cost plus insurance and freight (CIF) value of the product.
Venezuelan law allows for the exoneration of all or part of the import
duties levied upon such equipment and related supplies that are
indispensable for the various phases of the mining activities.
Pursuant to the exoneration rules contained in the existing law, the
Feasibility Study and the current economic model do not provide for
duties on imported goods but does contain a provision for the one
percent administration fee, which is not subject to exoneration. With
the majority of equipment manufactured outside of Venezuela, the import
duty exoneration has been assumed for all major equipment.
22.6 Capital and Operating Cost Estimates
- -------------------------------------------------------------------------------
22.6.1 Capital Cost Details
- -------------------------------------------------------------------------------
Initial capital expenditures listed in Table 22-1 of $638 million are
detailed as follows:
Mining Equipment includes all major mining equipment and mine support
equipment ($77 million). No contingency has been included.
Mine Development Costs include preproduction expenses of $18 million.
No additional contingency was applied to these estimates.
Mill Equipment capital of $242 million includes all crushing,
conveying, gold recovery and refining equipment, and mine
infrastructure (truck shop, warehouse, administration building,
laboratory, etc.). Engineering, procurement and construction
management costs ($97 million), plus a 10 percent contingency have been
included in these estimates ($59 million).
Tailings Dam ($14 million) includes all earthwork, construction, liner
systems and structures associated with these facilities for the first
stage of construction. A 10 percent contingency has been included in
these estimates.
Working Capital ($45 million) shown in Table 22-1 includes current
assets less current liabilities including outstanding receivables less
payables, and inventory items including spares, parts inventory, and
initial reagent charges. Costs for spares and initial fills have been
subtracted from the capital totals and allocated to inventory and
appears as working capital in the balance sheet for this analysis.
Working capital is based on 30 days of revenue in accounts receivable
and 30 days of operating costs in accounts payable.
22.6.2 Operating Cost Summary
- -------------------------------------------------------------------------------
The Brisas Project facility will process around 485 million tonnes of
ore over its planned 19-year mine life. In the first seven years of
production the plant will process a combination of hard rock and oxide
and sulfide saprolites. In the seventh year of operation the sulfide
saprolites will be exhausted. Oxide saprolite will continue to be
processed through the life of the project. The hard rock ore will be
processed at a rate of 70,000 tonnes per day or 25.2 million tonnes per
year. The estimated average operating costs for the project life are
shown in Table 22-2.
TABLE 22-1
Gold Reserve Inc.
Brisas Project, Venezuela
Feasibility Update
Base Case Key Economic Assumptions and Results
Base Case Assumptions
- -------------------------------------------------------------------------
Daily Mill Throughput 70,000 tonnes/day
Mine Life 18.5 Years
Gold Price $470/troy ounce
Copper Price $1.80/pound
Silver Price $7.90/troy ounce
Metallurgical Recovery
- -------------------------------------------------------------------------
Plant Recovery - Gold 82.7%
Plant Recovery - Copper 86.8%
Net Payable Metal - Gold 81.0%
Net Payable Metal - Copper 83.2%
Life of Mine Production
- -------------------------------------------------------------------------
Payable Gold 8.41 million troy ounces
Payable Copper 1,113 million pounds
Average Annual Production
- -------------------------------------------------------------------------
Payable Gold/year 456,000 troy ounces
Payable Copper/year 60 million pounds
Initial Capital Cost 1 (in millions US 2006 $)
- -------------------------------------------------------------------------
Mine $76.6
Mill $241.5
Tailings $14.1
Infrastructure $65.8
Owners Costs $65.3
Pre-Stripping $18.3
Indirect Costs (includes EPCM and Camp) $97.0
Contingency $59.4
Total Initial Capital $638.0
Initial Working Capital $44.5
Capital Costs (in millions US 2006 $)
- -------------------------------------------------------------------------
Initial $682.5
Sustaining Capital $157.2
Reclamation Expenditure $36.4
Total Capital $876.1
Cash Operating Costs Per Ore Tonne (in US 2006 $)
- -------------------------------------------------------------------------
Mining and Dewatering $2.08
Processing $2.59
G & A $0.42
Transportation & Freight $0.34
Smelting & Refining $1.02
Total Cash Operating Cost/Ore Tonne $6.45
Cost Per Ounce of Gold
- -------------------------------------------------------------------------
Cash Operating Costs2 $126
Exploitation Tax $16
Capital Cost (initial and sustaining) $111
Total Costs2 $253
Total Costs3 Excluding Sunk Costs $245
(1) A value added tax (VAT) of 14% or $73 million, is not included in
the initial capital as it should be recovered within the first few
years of construction and mining.
(2) Net of copper by-product credit.
(3) Net of copper credit and excluding, for purposes of the economic
model, sunk costs of approximately $70 million. Total expenditures,
capitalized and costs expensed, on the Brisas Project since its
acquisition by the Company in 1992 totals over US$100 million.
TABLE 22-2
Gold Reserve Inc.
Brisas Project, Venezuela
Feasibility Update
Base Case Average Operating Costs
Average
Category Units Annual Cost
- -----------------------------------------------------------------
Mine $million/year $54.6
Mill $million/year $68.0
G&A $million/year $11.0
Transportation & Offsite Treatment $million/year $35.7
- -----------------------------------------------------------------
Total $million/year $169.3
=================================================================
AverageTotal Cost/Ore Tonne $/tonne $6.45
AverageTotal Cost/Hard Rock Ore Tonne $/tonne $6.76
22.7 Economic Analysis
- -------------------------------------------------------------------------------
This Feasibility Study and subsequent studies
have established that the Brisas Project can be economically developed
by open pit mining followed by a gravity circuit, flotation to generate
a gold-copper concentrate, and cyanidation of cleaner tailings for gold
and silver recovery. This Update indicates that 10.4 million contained
ounces of gold in 485 million tonnes of ore at an average gold grade of
0.67 grams per tonne and an average copper grade of 0.13 percent can be
mined and processed economically to recover 8.6 million ounces of gold
and 1.2 billion pounds of copper. In addition, approximately 8.8
million ounces of silver are anticipated to be recovered as a
by-product with the gold, based on the metallurgical testwork.
Payable metals over the life of the mine after treatment deducts will
be approximately 8.4 million ounces of gold, 1.1 billion pounds of
copper, and 7.0 million ounces of silver.
A Base Case economic analysis was prepared for the Brisas Project using
a gold price of $470 per ounce, copper price of $1.80 per pound, and
silver price of $7.90 per ounce. The Base Case is based on the
three-year rolling average for metal prices as of September 2006.
Results for the Base Case are summarized in Table 22-3. Table 22-1
provides a summary of some of the key assumptions and additional detail
on the results of the analysis. Cash operating costs are presented for
gold on a net of by-product credit basis. Capital costs are in Table
22-1. Project payback is less than seven years.
Development of the project yields a pre-tax discounted cash flow rate
of return of 15.4 percent and a net present value of $783 million (5
percent discount rate) at a gold price of $470/oz, a silver price of
$7.90/oz, and a copper price of $1.80 per pound. Total pre-tax cash
flow is $1.91 billion.
Likewise, the Brisas Project yields an after-tax discounted cash flow
rate of return of 11.4 percent and a net present value of $445 million
(5 percent discount rate) at a gold price of $470/oz, a silver price of
$7.90/oz, and a copper price of $1.80 per pound. Total after-tax cash
flow is $1.28 billion.
The total initial capital is approximately $638 million, with an
additional $45 million in initial working capital and $157 million of
sustaining capital required over the 19 year mine life. The cash
operating cost per gold ounce produced is $126 after by-product
credits. When additional production taxes and preproduction stripping
are added to the capital costs, total cash and non-cash costs
(fully-loaded) are $253 per ounce.
Reserve estimates were based on a gold price of $400 per ounce, copper
price of $1.15 per pound, and no silver credits. Results from the
economic analysis at these prices are shown in Table 22-3. Since an
after tax total cash flow of $497 million is achieved the economic
criteria for the reserve statement are met. Silver is not included in
the reserve estimate but has been included in the economic model based
on metallurgical test results.
TABLE 22-3
Gold Reserve Inc.
Brisas Project, Venezuela
Feasibility Update
Reserve Case and Base Case Economic Evaluation
Reserve Case Base Case
---------- ---------
Gold Price ($/troy oz) $400 $470
- ----------------------------------------------------------------
Copper Price ($/pound) $1.15 $1.80
- ----------------------------------------------------------------
Silver Price ($/troy oz) $0.00 $7.90
- ----------------------------------------------------------------
Project Economics Pre-Tax ($ millions)
- ----------------------------------------------------------------
Cash Flow 713 1,906
NPV @ 5% 120 783
NPV @ 10% (135) 268
IRR 6.9% 15.4%
Project Economics After Tax ($ millions)
- ----------------------------------------------------------------
Cash Flow 497 1,283
NPV @ 5% 8 445
NPV @ 10% (199) 66
IRR 5.1% 11.4%
Cash Operating Cost ($ per oz Gold)1 $213 $142
Payback (years) 11.6 6.7
(1) Net of copper by-product credit and includes production taxes.
22.8 Base Case Evaluation
- -------------------------------------------------------------------------------
22.8.1 Major Assumptions
- -------------------------------------------------------------------------------
The following is a summary of major assumptions for the economic
analysis:
1. The evaluation assumes 100 percent equity with no debt financing
(or gold loan) for a 100 percent interest in the project.
2. The analysis was done in constant 1st Quarter 2006 US dollars
with no escalation of operating costs, capital costs, or revenue.
3. Pre-operating, preproduction, and development costs (prior to
Year 1) are capitalized until the operation is determined to be
substantially complete and ready for operation. These costs are then
amortized against the gold ounces of production. The Brisas Project
economic model assumes the amortization (computed by the units of
production method) of sunk costs of approximately $70 million and
preproduction costs of approximately $33 million. Total expenditures,
capitalized and costs expensed, on the Brisas Project since its
acquisition by the Company in 1992 totals over US$100 million.
4. Working capital for the project consists of initial supply
inventory, spare parts, and accounts receivable less accounts
payable. Accounts receivable are calculated for monthly revenue based
on a 30 day collection period. Accounts payable for cash operating
costs are based on a 30 day payment cycle.
5. Income from salvage at the end of the project life is assumed
to be zero.
6. Silver is not included in the mine geologic model but has been
included in the economic model based on metallurgical test results.
Silver provides $56 million in revenue over the life of the project and
has a $20 million impact on NPV at 5 percent.
7. Value-added taxes are deducted as an after-tax operating expense
and recovered after tax against exploitation tax and income tax.
Remaining VAT CERTs are assumed to be sold at 95 percent of the face
value in the open market after holding them in inventory for one year.
8. This Update includes income and exploitation taxes as described
in Section 22.5.
9. Venezuela is a member of the Andean Community and uses the
Andean Community customs tariff. The duty is an ad valorem duty
calculated on the cost plus insurance and freight (CIF) value of the
product. Venezuelan law allows for the exoneration of all or part of
the import duties levied upon such equipment and related supplies that
are indispensable for the various phases of the mining activities.
Pursuant to the exoneration rules contained in the existing law, this
Feasibility Study does not provide for duty taxes on imported goods but
does contain a provision for the 1 percent administration fee, which is
not subject to exoneration. With the majority of equipment
manufactured outside of Venezuela, the import duty exoneration has been
assumed for all major equipment.
22.8.2 Sensitivity Analysis
- -------------------------------------------------------------------------------
Sensitivity analyses were performed on gold price, copper price, metal
recovery, capital cost, and operating cost. The sensitivity analyses
indicate that project economics are most heavily influenced by metal
recovery and the gold price. A 10 percent change in total metal
recovery results in a +- $140 million change in after tax net present
value at a 5 percent discount rate. A $25 per ounce change in the gold
price results in approximately +- $74 million change in after tax net
present value at a 5 percent discount rate. Project economics are also
sensitive to changes in operating cost, with a 10 percent change
resulting in a +- $124 million change in after tax net present value at
5 percent. Project economics are less sensitive to change in capital
cost, with a 10 percent change resulting in a +- $56 million change in
after tax net present value at 5 percent. Results of the price
sensitivity analyses are shown in Table 22-4. All the analyses were
done on a 100 percent equity basis.
TABLE 22-4
Gold Reserve Inc.
Brisas Project, Venezuela
Feasibility Update
Economic Evaluation
Base Case and Price Sensitivity (Metal prices move together)
Base Case
--------------------------------------
Gold Price ($/ounce) $370 $420 $470 $520 $570
- -----------------------------------------------------------------
Copper Price ($/pound) $0.80 $1.30 $1.80 $2.30 $2.80
- -----------------------------------------------------------------
Silver Price ($/troy oz) $3.90 $5.90 $7.90 $9.90 $11.90
- -----------------------------------------------------------------
Project Economics Pre Tax ($ millions)
- -----------------------------------------------------------------
Cash Flow 187 1,043 1,909 2,833 3,756
NPV @ 5% (173) 303 783 1,298 1,812
NPV @ 10% (312) (23) 268 580 892
IRR 2.0% 9.5% 15.4% 20.9% 25.8%
Project Economics After Tax ($ millions)
- -----------------------------------------------------------------
Cash Flow 152 714 1,283 1,894 2,504
NPV @ 5% (189) 128 445 785 1,124
NPV @ 10% (320) (126) 66 272 478
IRR 1.7% 7.0% 11.4% 15.6% 19.3%
Cash Operating Cost
($ per oz Gold)1 $245 $194 $142 $82 $24
Payback (years) 17.3 10.2 6.7 5.2 4.3
(1) Net of copper by-product credit and includes production taxes.
23.0 ILLUSTRATIONS
- -------------------------------------------------------------------------------
The illustrations supporting the various sections of the report are
located within the relevant sections immediately following the
references to the illustrations, for ease of use. An index of tables
and illustrations is provided in the table of contents at the beginning
of the report.
24.0 CERTIFICATE OF QUALIFIED PERSON
- -------------------------------------------------------------------------------
Richard J. Lambert
165 S. Union Blvd., Suite 950
Lakewood, CO 80228
303-986-6950
As an author of the report entitled "NI 43-101 Technical Report, Brisas
Project, Venezuela, Feasibility Update" dated October 30, 2006 (the
"Technical Report") and prepared on behalf of Gold Reserve, Inc. (the
"Issuer"), I, Richard J. Lambert, P.E., do hereby certify that:
1. I am a Principal Mining Engineer with the international consulting firm
of Pincock, Allen & Holt and have been so since October 2004. My
current position is Vice President of Mining and Geological Services.
2. I am a Registered Professional Engineer in the state of Wyoming
(#4857), the state of Idaho (#6069), and the state of Montana (#11475).
3. I am a graduate of the Mackay School of Mines at the University of
Nevada, Reno with a Bachelors of Science degree in Mining Engineering
in 1980, and Boise State University, with a Masters of Business
Administration degree in 1995. I have practiced my profession
continually for 26 years.
4. I am a member of the Society for Mining, Metallurgy, and Exploration
(SME) since 1975 and a Registered Member (#1825610) since May 2006.
5. I am responsible for the preparation of Sections 1-6, general
information; Section 15, and Sections 18-23, final information. I have
not visited the Las Brisas Project site.
6. Since 1980 I have been involved in mine engineering, mine management,
mine operations and mine financial analyses, involving copper, gold,
silver, nickel, cobalt, uranium, oil shale, phosphates, coal and base
metals located in the United States, Canada, Zambia, Madagascar,
Turkey, Bolivia, Chile, and Venezuela.
7. As a result of my education and experience, I am a Qualified Person as
defined in National Instrument 43-101.
8. As of the date of the certificate, to the best of my knowledge,
information and belief, the technical report contains all scientific
and technical information that is required to disclose to make the
technical report not misleading.
9. I am independent of the Issuer in accordance with Section 1.4 of
National Instrument 43-101.
10. I have not received, nor do I expect to receive, any interest, directly
or indirectly, from Gold Reserve, Inc., any affiliate, or associate
company.
11. I have read National Instrument 43-101, Forms 43-101F1, and the
Technical Report has been prepared in compliance with that instrument
and form.
12. I consent to the filing of the Technical Report with any stock exchange
and other regulatory authority and any publication by them, including
electronic publication in the public company files on their websites
accessible by the public.
Dated at Lakewood, Colorado, this 30th day of October 2006.
s/ Richard J. Lambert, P.E.
_____________________________________
Richard J. Lambert, P.E.
Susan R. Poos
3900 S. Wadsworth Blvd., Suite 440
Lakewood, Colorado 80235
Phone (303) 969-8468
Fax (303) 969-9050
spoos@marston.com
I, Susan R. Poos, P.E., am a professional mining engineer under the
employ of Marston & Marston, Inc. 3900 S. Wadsworth Blvd., Suite 440 in
the city of Lakewood, Colorado, in the USA.
1. I am a registered professional engineer in the states of Colorado (No.
30975), and Texas (No. 87589) and a Registered Member of the Society of
Mining, Metallurgy and Exploration (SME).
2. I graduated from Colorado School of Mines with a B.S. in Mining
Engineering in 1982 and from Purdue University with an M.Sc. in
Industrial Engineering in 1987. I have practiced my profession
continuously since 1988.
3. Since 1988 I have been involved in mine design, mine management, and
reserve estimation in both open pit and underground operations,
involving copper, gold, coal, iodine, and base metals located in the
United States, Canada, Mexico, Chile, Argentina, Russia, Panama, and
Indonesia.
4. As a result of my education and experience, I am a Qualified Person as
defined in National Policy 43-101.
5. I am presently Vice President and Mining Consultant with the
international consulting firm of Marston & Marston, Inc. and have been
so since October 2005.
6. I visited the Brisas project in February 2004. During this visit I
discussed the plan of operation with the personnel, observed the
planned pit and waste dump areas, reviewed drill core and toured the
existing facilities.
7. I have assisted in the preparation of this report entitled "NI 43-101
Technical Report, Brisas Project, Venezuela, Feasibility Update" dated
October 30, 2006. I prepared the mine plans, production schedule and
mineral resource and reserve estimates that are contained this
report. I am responsible for Sections 7 through 14 and 17 and the
applicable portions of Sections 1, 2, 6, 19, 20, and 22.
8. The sources of information are noted and referenced in the report. The
information provided by the various parties is to the best of my
knowledge and experience is correct.
9. As of the date of this certificate, to the best of my knowledge,
information and belief, the technical report contains all scientific
and technical information that is required to be disclosed to make the
technical report not misleading.
10. I am independent of Gold Reserve Inc., in accordance with the
application of Section 1.4 of National Instrument 43-101.
11. I have read National Instrument 43-101and Forms 43-101F1 which became
effective December 30, 2005. This report has been prepared in
compliance with NI 43-101 and Form 43-101F1.
12. This report, as well as its conclusions and recommendations, are based
on the examination of available data and discussions with involved
technical personnel from Gold Reserve Corporation and Pincock, Allen &
Holt.
Dated at Lakewood, Colorado, this 30th day of October, 2006.
s/ Susan R. Poos, P.E.
______________________________________
Susan R. Poos, P.E.
Richard Addison, P.E., C Eng, Eur.Ing.
165 S. Union Blvd., Suite 950
Lakewood, Colorado 80228
Phone (303) 986-6950
Fax (303) 987-8907
dick.addison@pincock.com
I, Richard Addison, P.E., C Eng, Eur.Ing., do hereby certify that:
1. I am currently an associate Principal Process Engineer of:
Pincock, Allen & Holt
165 S. Union Blvd., Suite 950
Lakewood, CO 80228
USA
2. I graduated from the Camborne School of Mines in England as an Honors
Associate in 1964 and subsequently obtained a Master of Science degree
in metallurgical engineering from the Colorado School of Mines in
1968. I have practiced my profession continuously since 1964.
3. I am a Registered Professional Engineer (#3198) in the state of Nevada,
USA, a Charted Engineer in the U.K. (#20), and a registered European
Engineer in the EEC (#111916). I am a member of the American Institute
of Mining, Metallurgical, and Petroleum Engineers, the Mining and
Metallurgical Society of America, and the Institute of Materials,
Minerals and Mining in the U.K.
4. I have worked as a metallurgical engineer for a total of 42 years since
my graduation from university and have been involved in the evaluation
and operation of mineral properties for gold, silver, copper, lead,
zinc, tin, aluminum, iron, gypsum, limestone, barite, sulfur, pyrite,
oil shale, coal, and diamonds in the United States, Canada, Mexico,
Dominican Republic, Honduras, Nicaragua, Costa Rica, Panama, Venezuela,
Guyana, Peru, Ecuador, Bolivia, Argentina, Chile, Spain, Portugal,
Britain, Bulgaria, Indonesia, Papua New Guinea, the Philippines, Japan,
Tunisia, Ghana, Zambia, South Africa, Russia, Kyrghyzstan, and Australia.
5. I am responsible for the preparation of Section 16, Metallurgy and
Mineral Processing.
6. I have read the definition of "qualified person" set out in National
Instrument 43-101 ("NI 43-101") and certify that by reason of my
education, affiliation with a professional association (as defined in
NI 43-101) and past relevant work experience, I fulfill the
requirements to be a "qualified person" for the proposed of NI 43-101.
7. I have read National Instrument 43-101 and Form 43-101F1, and the
Technical Report has been prepared in compliance with that instrument
and form.
8. I consent to the filing of the Technical Report with any stock exchange
and other regulatory authority and any publication by them, including
electronic publication in the public company files on their websites
accessible by the public, of the Technical Report.
Dated in Lakewood, Colorado, this 30th day of October 2006.
s/ Richard Addison, P.E., C.Eng, Eur.Ing.
_______________________________
Richard Addison, P.E., C Eng, Eur. Ing.