Exploration, Geology, Alteration, and Mineralization of the Silicon Gold Prospect, Greater Bullfrog Hills – Bare Mountain District, Nye County, Nevada

The Silicon prospect is a new grass roots discovery located approximately 11 kilometers northeast of
the town of Beatty, in the western extent of the Yucca Mountains, southwestern Nevada. The project area saw
minor production in the early part of the 20th century from small scale opal-cinnabar workings and high purity
silica was mined between 1919 and 1929 from a small open cut within acid-leached tuff. Regionally, the district
contains bonanza quartz-adularia veins in rhyolitic volcanic rocks (Bullfrog, Mayflower), disseminated bulk
tonnage gold deposits in volcanic rocks (North Bullfrog), and Carlin-like deposits (Mother Lode, Secret Pass,
Sterling) in varying host rocks.
Silicon lies within the Southwestern Nevada volcanic field and the stratigraphic succession is
dominated by Miocene rhyolitic ignimbrites and ash-fall deposits. These are cut by complex listric normal
faults. Mineralization occurred at ~ 11.6 Ma in the hiatus between major ignimbrite events, in apparent
association with rhyolitic volcanism. There is a strong structural control to the mineralization with it being
centered on the Silicon-Tramway faults, here interpreted as a relay ramp to the large-scale Thompson fault to
the east which also forms a boundary to the mineralization. Mineralization remains open, particularly at depth
in high-grade (>3 g/t Au) quartz-pyrite-carbonate veins.
There is a large 4 km by 2 km surface alteration footprint, with advanced argillic alteration and
silicification centered on the Silicon-Tramway faults and extending to significant depths, >350 m below the
surface. Pervasive advanced argillic alteration, which on the present surface has steam heated characteristics,
preceded Au mineralization which is directly associated with black quartz-pyrite hydrothermal breccia
followed by quartz-(pyrite) and quartz-pyrite-carbonate epithermal-style veins. The latest hydrothermal event
was pink, coarse grained alunite veining which represents a return to extreme acidic conditions.
Silicon is interpreted as a high-level expression of a magmatic condensate-derived advanced argillic
alteration system. Gold deposition appears to have occurred under less acidic and intermediate to low
sulfidation conditions.
On-going exploration at Silicon since 2018 has delineated an inferred resource of 120.4 million tonnes
grading 0.87 g/t Au and 3.6 g/t Ag for approximately 3.4 million ounces Au and 14.2 million ounces Ag.