The Corcoran Canyon Project is in Nye County, Nevada, 80 km north of Tonopah and 19 km east of the Round Mountain gold mine (15 Moz Au).
Forty unpatented claims under lease and an adjacent 89 claims controlled 100% by Corcoran Canyon Mining Corp., a wholly owned subsidiary of Bullion River Gold Corp.
The project is within a regional north-trending mineralized belt that includes the volcanic-hosted and sediment-hosted gold-silver deposits of Goldfield, Tonopah, Midway, Manhattan, Round Mountain, Gold Hill, and Northumberland.
The project area is underlain by a Middle Tertiary (22-26Ma) caldera complex consisting of felsic ash-flow tuffs, tuffaceous sediments, and intrusions. The property lies along the margin of one of several nested calderas, one of which hosts the Round Mountain deposit. Widespread alteration and mineralization coincides with a district-scale, northeast-trending structural zone coinciding with a caldera margin.
Corcoran Canyon is a volcanic-hosted, low-sulfidation, silver-gold, and epithermal system extending for more than 5.5 km along a northeast-trending structural zone defined by alteration, veining, gold-silver mineralization, faulting, and intrusions. Mineralization occurs in quartz-vein stockworks and breccias within sericitized, argillized and silicified volcanic rocks. Arsenic, molybdenum, mercury, thallium, and antimony are strongly elevated with Au and Ag; base-metal contents are low. Strongly sericitized, alkali rhyolite stocks with quartz veinlets, gold –silver-moly mineralization are the likely source of mineralization.
The district contains a significant Ag-Au resource, the “Silver Reef” deposit, defined by drilling in the 1980’s. An indicated and inferred resource calculated in 1988 (Pre 43-101 standard) using 50-foot cross sections is:
Examples of significant drilled Ag-Au intersections in the resource area include 79.2 meters grading 8.2 opt Ag and 0.008 opt Au and 20.4 meters grading 1.20 opt Ag and 0.068 opt Au.
Between 1970 and 1990, approximately 100 holes were drilled within the exposed Ag-Au resource. Drill testing has been shallow, with only 8 holes known to be deeper than 800 feet (240m).
Fieldwork by Corcoran Canyon Mining Corp. in 2004 resulted in the recognition that the project contains mineralization with variable Ag:Au ratios. Recent rock-chip sampling has confirmed the presence of gold mineralization with a low Ag:Au ratio peripheral to the known Ag-Au resource. Examples include 1.47 g/t Au (9.5 g/t Ag) 1100m west of the resource and 1.7 g/t Au (9.5 g/t Ag) 400m south of the resource. Previous limited shallow drilling in these two areas has intersected gold mineralization, including .89 g/t Au (2.3 g/t high) over 15m with 4.1 g/t Ag at the first location and .75 g/t Au over 5m with 1.7 g/t Ag at the second. This Au-rich facies also contains higher As, Sb and Hg than Ag-rich mineralization.
A 3-dimensional drill model of the resource was completed in 2004, and it was recognized that gold-silver mineralization remains open along strike and at depth.
There is potential to significantly expand the known resource. Further, there is potential for mineralization to occur under post-mineral pediment cover (valley fill) east of the range front. The exposed mineral system extends to the range front, where Au-Ag mineralization and alteration occur. This site also coincides with a prominent sharp bend in the regional trends of the range-front fault system along the east side of the Toquima Range. Important Tertiary Au-Ag deposits in the Great Basin and surrounding area occur at flexure points along range-front fault systems (e.g., Round Mountain, Gold Hill, and Midway).
There is no work planned for 2008. Bullion River will evaluate joint venturing or selling this project.