Mine detail: Afterthought

Previously called 'Copper Hill'

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Location

Lat / long:

40.73596, -122.08331

Resource(M)

Primary:	Copper
Secondary:	Gold, Silver, Lead
Ore:	Bornite, Chalcocite, Chalcopyrite, Covellite, Galena, Limonite, Malachite, Pyrite, Sphalerite, Azurite, Tennantite, Tetrahedrite, Luzonite
Gangue:	Barite
Orebody form:	LENTICULAR
Discovery year:	1862

Production

Operation type:	Underground
Production size:	Small
Development status:	Past Producer
Production years:	1905 - 1952
First production started:	1873
Last production ended:	1952

Geology

Host rock:	Bully Hill Rhyolite
Host type:	Rhyolite
Tectonic:	Island Arc
Alteration processes:	Silicified, Pyritized, Sericite, Carbonatization, Albitization

References

MRDS	W025215
DEP	10077520
Reference	{Deposit:: ALBERS, J. P., AND ROBERTSON, J. F., 1961 , GEOL. AND ORE DEPOSITS OF EAST SHASTA, COPPER - ZINC DISTRICT, SHASTA COUNTY, CAL.: U.S. GEOLOGICAL SURVEY PROF. PAPER 388 , 107 P.}{Deposit:: LYDON, P. A., AND *RIEN, J. C., 1974 , CALIF. DIV. MINES AND GEOLOGY COUNTY REPT. 6 , SHASTA COUNTY, P. 31 , 104 .}{Deposit:: STINSON, M. C., 1957 , CALIF. JOURNAL OF MINES AND GEOLOGY, VOL. 53 , PG. 684 .}{Deposit:: Mosier, D.L., Berger, V.I., and Singer, D.A., 2009, Volcanogenic massive sulfide deposits of the world; database and grade and tonnage models: U.S. Geological Survey Open-File Report 2009-1034 [http://pubs.usgs.gov/of/2009/1034/].}{Production:: LYDON P. A., AND *RIEN, J. C., 1972}
Reporter	Tatkin, T.; Albers, John P.