SILVERSTONE RELEASES INITIAL MINERAL RESOURCE ESTIMATE FOR ITS COPALA SILVER PROJECT, SINALOA STATE, MEXICO
Highlights
- Initial independent mineral resource estimate completed for Copala silver project, Sinaloa State, Mexico
- Copala mineral resource estimate at the underground Animas Refugio Vein at a 90 g/t silver cut-off grade totals:
- Indicated category: 656,000 tonnes at a grade of 204gpt silver and 1.1gpt gold, containing 4.3 million ounces of silver and 23,000 ounces of gold or 5.5 million silver equivalent ounces(1)
- Inferred category: 345,000 tonnes at a grade of 145gpt silver and 0.8gpt gold, containing 1.6 million ounces of silver and 9,000 ounces of gold or 2.1 million silver equivalent ounces(1)
- Copala resource estimate at the surface La Colorada Vein-Mantos at 20 g/t silver equivalent (1) cut-off grade totals:
- Inferred resource: 2.5 million tonnes at a grade of 80gpt silver and 0.4gpt gold, containing 6.5 million ounces of silver and 30,700 ounces of gold or 8.1 million silver equivalent ounces (1)
Initial current mineral resource estimates of two well-mineralized zones on the Copala silver project have been completed by independent qualified person, as defined by NI 43-101, Robert Sim, P.Geo. Hugh Willson, P.Geo., is the company�s qualified person as defined by NI 43-101. Both have reviewed the contents of this news release.
To date, Silverstone has focused its drilling on two of the more than 9 known vein and manto systems on the Copala Property. These are the Animas Refugio vein and La Colorada vein-mantos.
On the Animas Refugio vein system, Silverstone has drilled 131 holes that total 15,184 meters. This drilling was distributed between four sectors that host historic workings: La Pipa, El Muerto, Clemens, and San Carlos. Vein mineralization in the combined Clemens-El Muerto Sector showed sufficient grade and continuity to warrant infill drilling with a goal of identifying a resource with potential to be developed by underground mining.
The Animas Refugio and La Colorada mineral resource estimates have been generated from drill hole sample assay results and the interpretation of geologic models, which relate to the spatial distribution of silver and gold. Interpolation characteristics have been defined based on the geology, drill hole spacing and geostatistical analysis of the data.
Mineral resources on the Animas Refugio Vein have been generated using the inverse distance weighting interpolation method with a nominal 2x5x2 meter block size. The long axis of the blocks are oriented parallel to the vein at an azimuth of 315 degrees.
On the La Colorada vein system, Silverstone has focused on an area with significant historic workings in a vein-mantos system, which occurs at varying depths from 0 to 50m below surface. Silverstone has drilled 64 Diamond drill holes totaling 6,454 meters in the La Colorada zone. Mineral resources at the La Colorada zone are generated using the inverse distance weighting interpolation method with a nominal 5 meter block size.
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Both deposits were subjected to significant capping of high grade due to drill hole spacing. This capping reduced the overall silver equivalent for the two zones by over 2 million ounces. It is believed that the historic mining at Copala was focused on high grade mineralization. It is management�s opinion that additional drilling and sampling may increase the population of high grade samples and result in less silver losses due to capping.
The following Summary Tables 1, 2 and 3 show overall project resource estimates at two silver cut-offs of 30 g/t and 90 g/t for the Aminas Refugio vein, reflecting underground operating conditions, and 20 g/t and 50 g/t silver equivalent for the La Colorada mantos, reflecting a potential open pit scenario.
Table 1: TOTAL INDICATED RESOURCES � ANIMAS REFUGIO VEIN
Cut Off
(Ag gpt) |
Tonnes
(000�s) |
Silver
(gpt) |
Gold
(gpt) |
Silver
(000�s oz) |
Gold
(000�s oz) |
Silver Equivalent
(000�s oz) |
|
30 |
1,273 |
132 |
0.74 |
5,405 |
30 |
6,905 |
|
90 |
656 |
204 |
1.11 |
4,307 |
23 |
5,457 |
Table 2: TOTAL INFERRED RESOURCES � ANIMAS REFUGIO VEIN
Cut Off
(Ag gpt) |
Tonnes
(000�s) |
Silver
(gpt) |
Gold
(gpt) |
Silver
(000�s oz) |
Gold
(000�s oz) |
Silver
Equivalent
(000�s oz) |
|
30 |
1,176 |
81 |
0.48 |
3,054 |
18 |
3,954 |
|
90 |
345 |
145 |
0.79 |
1,605 |
9 |
2,055 |
Table 3: TOTAL INFERRED RESOURCES � LA COLORADA MANTOS
Cut Off
Ag Eqv
(gpt) |
Tonnes
(000�s) |
Silver
(gpt) |
Gold
(gpt) |
Silver
(000�s oz) |
Gold
(000�s oz) |
Silver
Equivalent
(000�s oz) |
|
20 |
2,527 |
80.2 |
0.38 |
6,516 |
30.7 |
8,051 |
|
50 |
1,902 |
97.5 |
0.46 |
5,963 |
28 |
7,363 |
Note: (1) Silver equivalent is calculated by multiplying Gold grade by 50. No metallurgical recoveries were included.
* Resources are not mineral reserves as the economic viability has not been demonstrated.
** 1 kilogram = 2.2 lbs.; 31.103 grams = 1 oz. Troy
Full resource tables related to the above totals for the initial resource estimates are available on the Company�s website www.silverstonecorp.com ..
The exploration programs at Copala by Capstone Gold and subsequently Silverstone Resources Corp. were supervised by qualified person Hugh Willson, Vice President of Exploration for Silverstone. A quality control and assurance protocol was utilized on the project including blanks, standards and duplicates with each batch of assays. Silverstone�s samples were assayed by ALS Chemex in Vancouver. Core duplicate samples were sent to SGS Lakefield for analysis in Toronto. The independent resource estimation was done by qualified person Robert Sim of Sim Geological Inc. A detailed 43-101 compliant technical report on this resource estimate will be co-authored by qualified persons Robert Sim of Sim Geological Inc. and Hugh Willson, VP Exploration of Silverstone Resources Corp. The report will be available on the Company�s web site and www.sedar.com within 45 days.
2008 Copala Exploration Program
Silverstone is planning additional exploration on other manto zones at Copala in the 4th quarter of 2008 after the rainy season abates.
In addition, Silverstone is currently undertaking a property-wide stream sediment program that will aid the evaluation of the other veins and mantos that have not been drill-tested to date. Anomalous zones identified by this program will be followed up by detailed mapping, sampling, and drilling if warranted.
ABOUT SILVERSTONE
Silverstone is a Canadian based public silver mining company with 100% of its revenue from silver production. More information is available online at: www.silverstonecorp.com ..
For further information about the Company, please contact:
Chris Tomanik or Mark Patchett, Telephone: (604) 637-8151 / Facsimile: (604) 688-2180
Email: ctomanik@silverstonecorp.com or mpatchett@silverstonecorp.com
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Silverstone Resources Corp.
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CODE : SST.V |
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ISIN : CA82846B1013 |
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Silverstone Res. is a silver royalty company based in Canada. Silverstone Res. is listed in Canada and in Germany. Its market capitalisation is CA$ 243.7 millions as of today (US$ 218.3 millions, € 158.1 millions). Its stock quote reached its highest recent level on March 07, 2008 at CA$ 3.60, and its lowest recent point on November 21, 2008 at CA$ 0.30. Silverstone Res. has 123 077 000 shares outstanding. |