Mine detail: Empire - Northern Lights Deposit

Previously called ''

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Location

Lat / long:

40.60601, -117.02983

Resource(M)

Primary:	Gold, Silver, Copper
Ore:	Gold
Gangue:	Quartz, Chalcedony, Goethite, Jarosite, Hematite
Discovery year:	1875

Production

Operation type:	Surface-Underground
Deposit type:	replacement
Production size:	Small
Development status:	Producer
First production started:	1918

Geology

Host rock:	Harmony Formation
Host type:	Siltstone,Sandstone,Shale
Associated type:	Quartz Monzonite
Structure:	NE-trending faults ad the Dewitt Thrust Fault
Alteration processes:	Predominant alteration types affecting host rocks are silicification, pyritization, argillization, d sericitization. Gold mineralization is associated with fine-grained silica (locally chalcedonic) and pyrite replacing formerly calcareous siltstone and sandstone of the Harmony Formation. Extensive bleaching and argillization are believed to be caused by the breakdown of pyrite and liberation of sulfur as sulfate to form acid-leach type conditions. Monzonite-granodiorite porphyritic sills exhibit strong argillization and, locally, sericitization.

References

MRDS	M231333
DEP	10310309
Reference	{Deposit:: Roberts, R.J. And Arnold, D.C., 1965, Ore Deposits of the Antler Peak Quadrangle, Humboldt and Lander Counties, Nevada: U.S.G.S. Prof. Paper 459-B.}{Deposit:: Stewart, J. H., Mckee, E. H., and Stager, H. K., 1977, Geology and Mineral Deposits of Lander County, Nevada, NBMG Bull. 88.}{Deposit:: Schmidt, K. W., Wotruba, P. R., and Johnson, S. D., 1988, Gold-Silver and Related Mineralization at Copper Basin, Nevada, in Gold Deposits Of North Central Nevada, Special Publication #8, the Geological Society of Nevada, Reno.}{Deposit:: Long, K.R., DeYoung, J.H., Jr., and Ludington, S.D., 1998, Database of significant deposits of gold, silver, copper, lead, and zinc in the United States; Part A, Database description and analysis; part B, Digital database: U.S. Geological Survey Open-File Report 98-206, 33 p., one 3.5 inch diskette.}{Deposit:: Doebrich and Theodore, 1996.}{Deposit:: Geological Society of Nevada, 1999, Geology and Gold Mineralization of the Buffalo Valley Area, Northwestern Battle Mountain Trend; GSN Special Publication No. 31, 1999 Fall field trip Guidebook.}{Deposit:: Wendt, Clancy, 2004, Technical Report on the? ICBM/COPPER BASIN Property, Lander and Humboldt Counties, Nevada, Staccato Gold website, : http://www.staccatogold.com/i/pdf/icbm-43-101.pdf}
Reporter	LaPointe, D.D., Schruben, Paul G.