Under an earn-in agreement with Liberty Silver Corp.
This system is very similar to Potosi in Bolivia including an association with a high tin- content rhyolite and silver selenides whose type locality is Potosi. If the Potosi model is correct, there should be a larger sulfide resource to the west under the pediment. Current efforts are focused on bringing a leachable oxide resource into production. See non-compliant resource estimate below.
The property is located about 40 kilometers (25 miles) northwest of the Rochester Silver Mine (one of the largest silver mines in the U.S.) and 16 kilometers (10 miles) southeast of the Seven Troughs gold district.
The property consists of unpatented mining claims and 5,000 acres of fee land, in total about 5,800 acres (2,347 hectares).
Silver mineralization was discovered at Trinity by U.S. Borax in 1981 and the property was subsequently explored under a joint venture agreement between U.S. Borax and Santa Fe Pacific Gold Corp. Open-pit mining began in 1987, and over a two-year period approximately 5 million oz of silver were produced from 1.1 million tons of oxide ore grading 6 ounces per ton silver , utilizing heap leach technology. Reports prepared by U.S. Borax at the conclusion of mining indicate that the property still contains about 4 million tons of silver mineralization grading over 2 ounces per ton silver (non 43-101 compliant). The property was subsequently investigated by Santa Fe Pacific Gold during the period 1990 to 1992, but did not see further exploration until AuEx and Piedmont Mining conducted limited drilling in 2006 and 2008. This drilling encountered high grade silver values below and adjacent to the open pit, but cash flow issues with the joint venture partner prevented follow-up exploration of these and similar targets on the property.
Trinity Silver is a Tertiary-aged, volcanic-hosted, epithermal deposit of sulfide veins and stockworks with widespread illitic alteration. The sulfide mineralogy includes pyrite, galena, sphalerite, arsenopyrite, silver-bearing tetrahedrite, pyrargyrite, and stannite. Mineralization is associated with rhyolites and high tin values of up to 0.05% in 2 meter (5 foot) drill intervals make this an interesting possible analogue to the major silver deposits in Bolivia.
The possibility that porphyry copper-style mineralization occurs at depth is suggested by the strength of the illitic alteration, in combination with a crude district-wide zonation that includes a central copper-rich zone, an intermediate base metal-rich zone, and a peripheral silver-rich zone. In plan view, only a portion of the concentric zoning pattern has been tested by drilling and a number of vein and porphyry targets exist at depth.
Airphoto of the pit (black polygon) showing extensions in pink The property boundary to the east is now part of the claim package.
Photo of typical sulfide ore as a friable matrix in a rhyolite breccia
Compliant resource based on $17/oz Ag price, NI43-101, December 29, 2009.
Inferred oxide resources at various cut off grades:
|Inferred Oxide Resources
||oz Ag contained
Inferred sulphide resources at various cut off grades:
(oz/ton Ag equiv)
|Inferred Sulfide Resources
||oz/ton Ag equiv