| Lat / long: | 35.71, -114.84082 |
| Primary: | Silver, Gold |
| Secondary: | Zinc, Lead, Copper |
| Ore: | Gold |
| Gangue: | Quartz, Calcite, Hematite, Clay |
| Orebody form: | subhorizontal lenses |
| Discovery year: | 1857 |
| Operation type: | Surface-Underground |
| Deposit type: | fault zone |
| Production size: | Small |
| Development status: | Past Producer |
| First production started: | 1863 |
| Last production ended: | 1970 |
| 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. |
| 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. |