Castle Resources Reports Major Increase in Mineral Resource at the Granduc Copper Project
21.02.2012 | Marketwired
![Castle Resources Reports Major Increase in Mineral Resource at the Granduc Copper Project](https://www.goldseiten.de/media/goldseiten-news.jpg)
- Inferred Resource: 36.6 Million Tonnes Grading 1.26% Cu Containing 1.013 Billion Pounds of Copper, 155,000 Ounces of Gold and 11.4 Million Ounces of Silver (C$40 NSR Cut-Off)
- Exploration Potential Estimated to Contain an Additional 15 to 25 Million Tonnes Grading Between 1.2 to 1.5% Cu (C$40 NSR Cut-Off)
TORONTO, ONTARIO -- (Marketwire - Feb. 21, 2012) - Castle Resources Inc. (TSX VENTURE: CRI) ("Castle" or the "Company") is pleased to provide investors with an updated NI 43-101 compliant resource estimate for the Granduc Copper Project near Stewart, British Columbia.
Granduc Copper Project Mineral Resource Statement, February 17, 2012
Resource Cut-off Quantity Copper
Grade Gold
Grade Silver
Grade NSR
Value Contained
Copper Contained
Gold Contained
Silver
Category (NSR
C$) (millions
of tonnes) (%
Cu) (g/t
Au) (g/t
Ag) (C$) (millions
of lbs) (ounces) (ounces)
Indicated 40 10.4 1.25 0.14 10.6 90.89 286.1 47,000 3,500,000
Inferred 40 36.6 1.26 0.13 9.7 90.25 1013.2 155,000 11,400,000
NSR calculation using the following parameters. US$to C$Exchange is 1 : 0.92, Cu Price = US$3.25 / lbs., Au Price = US$1275 / troy ounce, Ag Price = US$21 / troy ounce Cu recovery at 91.7%, Au recovery = 62.56%, Ag recovery = 80.96%, Selling cost for Cu at US$0.312 / lbs., Au at US$5 / ounce, Ag at US$0.35 / ounce, Conversions: 31.1035 g / troy ounce, 2204.6 lbs. / tonne
"This impressive update clearly demonstrates that the Granduc is now a major mineralized copper resource with significant exploration upside," stated Mr. Mike Sylvestre, President & CEO of Castle Resources. "In less than 18 months of exploration we have identified 1.3 billion pounds of copper primarily downdip beneath the historic mine workings. What is more impressive is that the highly consistent mineralized zones remains open at depth and on strike, suggesting that as we aggressively continue to drill there exists strong potential to demonstrate the latest Granduc resource is part of a much larger copper-rich system."
The resource estimate was prepared by SRK Consulting (Canada) Inc. (SRK) of Vancouver B.C., an independent, international consulting practice.
Granduc Copper Project Indicated Mineral Resource, February 17, 2012
Cut-off Quantity Copper
Grade Gold
Grade Silver
Grade NSR
Value Contained
Copper Contained
Gold Contained
Silver
(NSR
C$) (millions
of tonnes) (%
Cu) (g/t
Au) (g/t
Ag) (C$) (millions
of lbs) (millions
of ounces) (millions
of ounces)
20 11.0 1.20 0.14 10.4 87.57 291.1 0.049 3.7
30 10.8 1.22 0.14 10.5 88.95 289.8 0.049 3.6
40 10.4 1.25 0.14 10.6 90.89 286.1 0.047 3.5
45 10.1 1.27 0.14 10.7 92.26 282.6 0.046 3.5
50 9.8 1.29 0.14 10.8 93.78 278.1 0.045 3.4
55 9.4 1.32 0.15 10.9 95.35 272.6 0.044 3.3
60 8.9 1.35 0.15 11.0 97.30 264.8 0.042 3.2
65 8.3 1.39 0.15 11.2 99.77 253.8 0.040 3.0
70 7.7 1.42 0.15 11.3 102.34 241.4 0.038 2.8
80 6.2 1.51 0.16 11.8 109.06 206.9 0.032 2.3
100 3.3 1.77 0.19 12.9 126.16 128.6 0.020 1.4
NSR calculation using the following parameters.
US$ to C$ Exchange is 1 : 0.92
Cu Price = US$ 3.25 / lbs., Au Price = US$ 1275 / troy ounce, Ag Price = US$ 21 / troy ounce
Cu recovery at 91.7%, Au recovery = 62.56%, Ag recovery = 80.96%
Selling cost for Cu at US$ 0.312 / lbs., Au at US$ 5 / ounce, Ag at US$ 0.35 / ounce
Conversions: 31.1035 g / troy ounce, 2204.6 lbs. / tonne
Granduc Copper Project Inferred Mineral Resource, February 17, 2012
Cut-off Quantity Copper
Grade Gold
Grade Silver
Grade NSR
Value Contained
Copper Contained
Gold Contained
Silver
(NSR
C$) (millions
of tonnes) (%
Cu) (g/t
Au) (g/t
Ag) (C$) (millions
of lbs) (millions
of ounces) (millions
of ounces)
20 38.1 1.22 0.13 9.5 87.94 1028.4 0.157 11.6
30 37.7 1.23 0.13 9.6 88.59 1025.7 0.157 11.6
40 36.6 1.26 0.13 9.7 90.25 1013.2 0.155 11.4
45 35.6 1.27 0.13 9.8 91.55 999.9 0.152 11.2
50 34.4 1.30 0.13 10.0 92.99 983.5 0.149 11.1
55 32.7 1.33 0.14 10.2 95.18 956.3 0.144 10.7
60 30.7 1.36 0.14 10.3 97.81 920.5 0.138 10.2
65 28.1 1.41 0.14 10.6 101.01 871.8 0.129 9.6
70 25.9 1.45 0.15 10.9 103.86 826.7 0.122 9.1
80 21.2 1.54 0.15 11.7 110.17 718.5 0.105 8.0
100 12.5 1.74 0.17 13.2 124.76 480.6 0.069 5.3
NSR calculation using the following parameters.
US$ to C$ Exchange is 1 : 0.92
Cu Price = US$ 3.25 / lbs., Au Price = US$ 1275 / troy ounce, Ag Price = US$ 21 / troy ounce
Cu recovery at 91.7%, Au recovery = 62.56%, Ag recovery = 80.96%
Selling cost for Cu at US$ 0.312 / lbs, Au at US$ 5 / ounce, Ag at US$ 0.35 / ounce
Conversions: 31.1035 g / troy ounce, 2204.6 lbs. / tonne
SRK believes the Mineral Resource is most accurately represented at a C$40 NSR cut-off, which incorporates the potential value of copper, gold and silver mineralization. The NSR and cut-off parameters are based upon preliminary test work and reasonable assumptions based upon similar deposits.
The Mineral Resources summarized above are not Mineral Reserves and do not have demonstrated economic viability. All figures have been rounded to reflect the relative accuracy of the estimates. SRK is not aware of any environmental, permitting, legal, title, taxation, socio-political or marking issues that would material effect the Mineral Resource. The resource estimate was completed by QP Michael Johnson, P.Geo., and Senior Consultant with SRK, who is independent of the Company.
When compared to the 2010 Mineral Resource estimate which was reported at a 0.8% copper cut-off, the Mineral Resource estimate has increased from 3.8 Mt of Indicated and 15.8 Mt of Inferred material to 8.9 Mt of Indicated and 31.1 Mt of Inferred material. The average grade of the Indicated material has dropped from 1.59% Cu to 1.35% Cu, while the grade of the Inferred material remained essentially unchanged at 1.34% Cu.
The Mineral Resource estimate is based on a database containing approximately 2,104 drillholes and 45,000 copper assays and 12,500 precious metal assays. Historical data was verified wherever possible against mine records including logs, sections and plans, however not all survey or assay data could be verified. Drilling completed by Castle in 2010 and 2011 as well as re-sampling of historical core was used to further validate the data. All assays from the 2010 and 2011 drilling were independently verified by SRK. SRK completed a site visit to the property in June and July 2011 during the Castle drill program but did not complete any independent sampling. SRK believes the data of sufficient quality for the definition of the Mineral Resource.
The Granduc copper deposit is a volcanogenic massive sulphide deposit ("VMS") with tabular, stratified mineralization zones which have been modified by several phases of folding. Structural modification has significantly remobilized the mineralization, thinning and thickening mineralized lenses throughout the deposit. SRK created grade shell models at a 0.7% cut-off for nine (9) domain lenses, using historical sections and plans as a guide. Seven (7) of these domains lie within the Main Zone where historical mining took place and two lenses were quantified within the North Zone, approximately 1 km north of the Main Zone. The third Granduc Zone, South Zone, has now been incorporated into the resource with the extension of continuous mineralization lenses from the Main Zone into the South Zone. All zones were modeled at a minimum width of approximately 2 m. In order to preserve continuity, SRK included some lower grade material between lenses as well as along strike. Within the Main Zone, the 2010 and 2011 drilling has now defined the down dip practical limit to the mineralization, which extends to approximately sea level. As well, the Main Zone mineralization seems to be terminated to the north, but remains open to the south at depth. The North Zone lenses remain open in all directions.
For the Main Zone, the copper mineralization was estimated by ordinary kriging into blocks of 2m by 10m by 10m (X, Y, and Z). The North Zone copper mineralization was estimated using inverse distance squared methods into similar sized blocks. For volumetric accuracy, blocks were sub-blocked to 0.5m by 2.5m by 2.5m. Blocks were categorized into Indicated and Inferred classes based upon the density of drilling information available. Blocks immediately below the lower limits of the underground mining where density of underground drilling was highest were classed as Indicated. Blocks further away from the mining levels where drillhole spacing was wider was classed as Inferred.
In the current Mineral Resource, gold and silver values were estimated for the first time, but within the Main-South Zones only. The North Zone lacks sufficient data to estimate precious metals at this time. Gold and silver assay results were based upon the 2005/6 Bell Copper drillholes, the 2010 and 2011 Castle sampling, as well as 2010 and 2011 re-sampling of historic drillholes. Gold and silver values were estimated into the block model using inversed distance squared methods. Gold and silver values have not been estimated for the North Zone, which accounts for approximately 10% of the Inferred Mineral Resource. The density of the gold and silver sample data is less than the copper data and results in a reasonable, but less confident estimate of gold and silver grade. Considering that the gold and silver mineralization contributes a small portion of the Mineral Resource estimate value, the data is considered sufficient for this stage of exploration.
The Mineral Resources are limited to unmined areas based on a model of the historic mining limits. The historic mining limits were determined from records filed with the government in 1984. At this time SRK has not gained underground access and therefore cannot directly verify the boundary. SRK believes that this boundary has been conservatively defined on reliable records.
In addition to the Mineral Resources, SRK assessed the Exploration Potential defined by wider spaced drilling data. In 2011, the Exploration Potential was defined throughout the North, Main and South Zones. At this this time, Exploration Potential has been limited to material in the North and South Zones as the Main Zone has reasonably quantified the limits of the mineralization. The current Exploration Potential is based upon approximately 16 North Zone drill holes that have been correlated with the resource domains, but are too widely spaced to define a resource. In the South Zone, 2011 drilling was unable to reach the southern limits of mineralization below an elevation of approximately 400m AMSL. In the south, the Exploration Potential is defined by the down-dip extension of mineralization between 200m and 400m AMSL as well as some peripheral gaps in the estimate where drill density was insufficient to quantify resource material. In the North Zone, the Exploration Potential has been defined by correlating widely space drillholes largely above the Mineral Resource. The resource is defined in an area where drilling density from an exploration drift was high enough to accurately quantify the resource. Fans of drilling from widely spaced surface and underground holes have been used to quantify the Exploration Potential. In 2011, three holes were completed in the North Zone and all holes intersected significant mineralization which exceeded expected thickness, however the data was insufficient to refine further Mineral Resources in the North Zone.
The potential quantity and grade of the Exploration Potential is conceptual in nature and there has been insufficient exploration to define a Mineral Resource. It is uncertain if further exploration will result in the target being delineated as a Mineral Resource.
Granduc Exploration Potential
February 17, 2012
Estimated Quantity Range Estimated Grade Range
(millions of tonnes) (Cu %)
15 to 25 1.2 to 1.5 %
Based upon a cut-off NSR Value of $40
Brad Leonard, P. Geo., Castle's Exploration Manager, is the Qualified Person responsible for the scientific and technical work (as defined under National Instrument 43-101) discussed in this press release, and has reviewed this press release.
About Castle Resources
Castle is a Toronto-based junior mineral development company focusing on high-quality, advanced projects. Management's goal is to continue the redevelopment of the 100% owned past producing Granduc Copper Mine in Stewart, B.C. For more information please visit the Castle Resources' website at www.castleresources.com.
Disclaimer
Certain statements contained in this news release may contain forward-looking information within the meaning of Canadian securities laws. Such forward-looking information is identified by words such as "estimates", "intends", "expects", "believes","may", "will" and include, without limitation, statements regarding the company's plan of business operations (including plans for progressing assets), estimates regarding mineral resources, projections regarding mineralization and projected expenditures. There can be no assurance that such statements will prove to be accurate; actual results and future events could differ materially from such statements. Factors that could cause actual results to differ materially include, among others, metal prices, risks inherent in the mining industry, financing risks, labour risks, uncertainty of mineral resource estimates, equipment and supply risks, title disputes, regulatory risks and environmental concerns. Most of these factors are outside the control of the company. Investors are cautioned not to put undue reliance on forward-looking information. Except as otherwise required by applicable securities statutes or regulation, the company expressly disclaims any intent or obligation to update publicly forward-looking information, whether as a result of new information, future events or otherwise.
This news release does not constitute an offer to sell or solicitation of an offer to sell any of the securities in the United States. The securities have not been and will not be registered under the United States Securities Act of 1933, as amended (the "U.S. Securities Act") or any state securities laws and may not be offered or sold within the United States or to a U.S. Person unless registered under the U.S. Securities Act and applicable state securities laws or an exemption from such registration is available.
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Contact Information
Castle Resources Inc.
Mike Sylvestre
President & CEO
416-366-4100
mike@castleresources.com
Castle Resources Inc.
Lenny Foreht
VP Corporate Development
416-644-9003
lforeht@castleresources.com
www.castleresources.com