Troy Gold-Silver Project
Troy Gold-Silver Project, Nye County, Nevada
Brocade Metals Corp.
The Troy gold-silver project is located in the Grant Range of eastern Nye County, Nevada, approximately 150 km east of Tonopah and 230 km north of Las Vegas. The project consists of 20 (7 existing plus 13 new) contiguous mineral claims that cover 167.22 (20 claims x 8.361/claim) hectares of land centered approximately on the historic Locke gold-silver mine.
At Troy, high-grade gold-silver mineralization occurs within massive mesothermal quartz veins, vein breccias and narrower sheeted vein and stockwork zones. The quartz system is exposed for 300 meters along the sheared, northerly trending contact between hangingwall recrystallized limestone of Cambrian age and footwall quartz monzonite of the Tertiary (23 Ma) Troy pluton.
Gold-silver mineralization was first identified at the project in 1867 and small scale mining commenced in 1869. The only recorded production took place from 1948-1950 during which 1,762 tons of ore were extracted from limited stoping on three levels yielding 641 ounces of gold (0.36 oz/ton Au) and 334 ounces of silver (0.19 oz/ton Ag) . Stopes developed during this period commonly are 0.8 – 3.0 meters wide. All mining activities appear to have ceased in the late 1950s. Little work of any kind took place from the 1960s to the late-1980s.
Recent assessments (late 1980s to early 2000s) of the project by multiple companies include sampling of surface and underground quartz exposures, mine dumps, mineral processing facilities, and tailings piles. In 2004, Miranda Gold Corp determined that stopes were developed on multiple ‘stacked’ north-trending, moderately east-dipping veins that overprint the massive quartz. Four of its stope samples returned values > 34.3 grams/tonne Au (1.0 oz/ton Au) including a high of 575 grams/tonne Au (16.8 oz/ton Au).
In 2007, Portage Minerals Inc. completed a multi-parameter exploration program on the project that included a property-wide soil geochemical survey, focused IP/Resistivity and CSAMT surveys, and rock chip sampling and surveying of the main Locke mine underground workings. Permitting for a 6,000 foot diamond drill program was also initiated.
The soil geochemical program identified several zones of anomalous gold outbound of the mine and a strong northwest trending IP anomaly in the southeast part of the survey area may be indicative of a fault zone. The underground mapping and sampling confirmed the character and extent of gold mineralization seen in earlier sampling.
Limited chip sampling by Brocade in 2014 returned values up to 39.1 grams/tonne verifying the previously reported high gold grades. Gold mineralization is associated with grey, late-stage vuggy, sugary limonitic quartz and minor sphalerite, galena and arsenopyrite, and a strong gold-bismuth correlation suggests that mineralization is part of an intrusive-related mesothermal gold vein system. Compiled data for the Troy project reference only one exploration drillhole which apparently was terminated in mineralized limestone before reaching the vein.
The Troy project hosts mesothermal vein system with potentially economic concentrations of gold and silver. Underground and surface workings show that the mineralized system includes three or more sub-parallel ‘stacked’ high-grade veins with down-dip dimensions of at least 180 meters. Select high-grade areas of the project may be suitable for near term bulk sampling or test mining. More work is required to define grade continuity and vein widths in the underground workings, and to prioritise areas for potential development.
Gold grades in mesothermal vein systems commonly persist to considerable depth, and therefore potential for undiscovered high-grade gold mineralization beneath the level of the underground workings of the Locke mine is considerable. The stacked vein system can be readily tested with a series of west-oriented angled drillholes 150-200 meters in length. The potential for mineralization along strike of the known zones and within limestones at other locations where they are in contact with the Troy pluton are also compelling exploration targets.