Surface Prospecting for Petroleum in Buena Vista Valley, Pershing County, Nevada

Buena Vista Valley in north-central Nevada has received attention
as a prospective basin for petroleum, since a well drilled in 1993
for precious metal exploration flowed unchecked for four and a half
days, producing an estimated 2.3-2.6 million gallons of hot water
and 500 barrels of oil before it was capped. This incident prompted
the USGS to conduct soil gas surveys in Buena Vista Valley to test
the possibility that hydrocarbon gases, measured at the surface,
might reveal areas of underlying petroleum accumulation. Gases
were measured in the field using a truck-mounted mass spectrometer,
and C1-C5 hydrocarbon gas anomalies were found in an area
that may reflect an undiscovered oil deposit. Source-rock analysis of
cuttings from a separate well drilled in the valley by an independent
oil producer indicate that Tertiary shales could be the source of oil.