The Talapoosa-Appaloosa Epithermal Au-Ag Project-A Reinterpretation and Update, Lyon County, Nevada

摘要

The Talapoosa-Appaloosa Project comprises a 5 mile long by 1.5 mile wide, west-northwest trending, low-sulfidation epithermal Au-Ag district; located 30 miles east of Reno, Nevada. Talapoosa was discovered in 1863 by prospectors from the Comstock-Virginia City district. Small-scale historic mining reportedly produced 5,000 oz of gold. Modern exploration has focused around the historic Talapoosa workings, where over 600 holes have been drilled since the 1970s. Gunpoint Exploration Ltd. acquired the property in 2010 and re-logged available drill core, drilled an additional 7,000 feet of orientated PQ core and re-interpreted the controls to mineralization, resulting in a 40% increase in the contained Au oz. as well as a 20% increase in average Au grade. The most recent NI43-101 Resource Estimate for Talapoosa, completed in 2013, comprises a Measured and Indicated resource of 1.01M oz. Au averaging 1.11 g/t Au (0.032 opt Au) and 13.6 M oz. Ag averaging 14.97 g/t Ag (0.437 opt Ag). This Talapoosa resource comprises a 2,000 feet by 800 feet zone constrained within the parallel bounding fault-planes of the north-northwest trending Talapoosa structure where both the fault-zone and mineralization dip approximately 70° to the south. Fault-planes within the Talapoosa structure divide the resource into three zones, the Main Zone in the north (which is well exposed and oxidized), the down-faulted and less oxidized Bear Creek Footwall Zone, and to the south the Bear Creek Hangingwall Zone. The Dike Adit and East Vein areas are faulted extensions to the west and east. Vein mineralization is most strongly developed within a gently south-dipping welded dacite lithic tuff unit at the base of the late-Miocene Stagecoach Hills Volcanics, and is associated with silica-sericite alteration. The overlying andesitic units and underlying non-welded tuffs are less strongly mineralized due to the lower structural competency of these units. Mineralization within the Main Zone, Bear Creek Hangingwall Zone, and the off-faulted Dike Adit and East Hill areas, typically consists of massive white chalcedony veins with less than 1% pyrite and marcasite and minor electrum. The Bear Creek Footwall Zone consists of narrow veinlets of fine-grained gray to red (hematitic) silica-pyrite-marcasite, gray amorphous very fine grained silica-sulfide, and pyrite-marcasite-chlorite veining. Recognition of two distinct and separate un-oxi-dized-mineralization types at Talapoosa has metallurgical implications for the future development of the project. The Appaloosa structure, approximately one mile north of Talapoosa, hosts a well-preserved, high-level, epithermal system that remains underexplored. Superior Oil Company drilled five, vertical, shallow percussion holes in the northwest part of the Appaloosa structure in the mid-1970s, but no systematic exploration is known to have been undertaken since that time.