Mine detail: Eldorado Gold Property

Previously called 'WBG deposit (Wall Street-Black Hawk-Gracey)'

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Location

Lat / long:

35.71, -114.84082

Resource(M)

Primary:	Silver, Gold
Secondary:	Zinc, Lead, Copper
Ore:	Gold
Gangue:	Quartz, Calcite, Hematite, Clay
Orebody form:	subhorizontal lenses
Discovery year:	1857

Production

Operation type:	Surface-Underground
Deposit type:	fault zone
Production size:	Small
Development status:	Past Producer
First production started:	1863
Last production ended:	1970

Geology

Host rock:	Nelson Monzonite, Patsy Mine Volcanics
Host type:	Monzonite,Mafic Intrusive Rock,Andesite,Dacite
Associated type:	Gneiss,Schist
Structure:	The northern Eldorado Mountains are characterized by many west-dipping listric normal faults which sole into a west-dipping detachment, all formed about between 15 and 10 Ma due to regional extension. The structural style changes markedly in the southern Eldorado Mountains, where Tertiary volcanic strata dip west and are cut by east-dipping listric faults. The Eldorado Canyon and mining district are located between the two structurally distinct areas and represent an ?accommodation zone?., The deposit is bounded on all sides by post-mineral, high-angle faults.
Tectonic:	The deposit is situated within a probable structural ?accommodation zone? marking the boundary between different styles of faulting in the northern El Dorado mountains and the southern portion of the range.
Alteration processes:	Propylitic alteration is widespread throughout the host rocks. Anomalous gold also occurs in zones of local silicification, argillic alteration, and quartz-alunite veining.

References

MRDS	M031039
DEP	10310510
Reference	{Deposit:: Koschmann and Bergendahl, 1968}{Deposit:: Longwell and others, 1965}{Deposit:: Robinson, J.P., 1996, in Coyner, A.R., and Fahey, P.L., eds., Geology and ore deposits of the American Cordillera, 1995; symposium proceedings: Reno, Geological Society of Nevada, v. 1, p. 567-579}{Deposit:: Wyman, R.V., 1987, in Johnson, J. L., ed., Bulk Mineable Precious Metal Deposits of the Western United States, Geological Society of Nevada, p. 109-113.}{Deposit:: AMH 1997 entry for Nelloro Corp.}{Deposit:: Long, K.R., DeYoung, J.H., Jr., and Ludington, S.D., 1998, Significant deposits of gold, silver, copper, lead, and zinc in the United States: U.S. Geological Survey Open-File Report 90-206A, 33 p.; 98-206B. one 3.5 inch diskette.}
Reporter	LaPointe, D.D., Schruben, Paul G.