Description
H.C. Brougher (silver discovery); Runge and Rochelle (gold discovery)
Commodities
PrimarySilver, Gold
TertiaryMolybdenum, Copper, Lead, Zinc
Commodity typeM
Deposit
Deposit typevein/lode
Model150: Epithermal vein, Comstock
Deposit sizeS
Orebody formTABULAR
Ore controlOre formation was controlled by fracturing and shear zones and brecciation of rhyolite
Materials
Ore mineralsGold, Cerargyrite, Argentite, Molybdenite, Powellite, Ferrimolybdite, Sphalerite, Chalcopyrite, Galena, Tetrahedrite, Sericite, Pyrite, Adularia, Quartz, Kaolinite
GangueLimonite
Geology
Host rockFelsic Volcanic Rock · "Fraction Breccia", "Siebert Tuff"
Associated rockFelsic Volcanic Rock,Rhyolite,Volcanic Breccia (Agglomerate),Andesite · "Oddie Rhyolite", "Divide Andesite"
StructureA conspicuous set of northwest trending, high angle, right-lateral strike-slip faults bisect the Tonopah Divide district. The Tonopah Divide shaft developed the Divide lode which occupies the large Divide fault (Boden, 1992). On the west side of Gold Mountain the Mormon Girl fault appears to be a parallel right lateral fault of this set. Between these major faults are transcurrent north-northeast trending faults which accommodated minor right-lateral strike-slip motion. These fault sets clearly postdate earlier gold mineralized faults of the E-W trending and north dipping Gold Zone. The Gold Zone is parallel to and an easterly extension of the N 80?E listric Kernick fault on Hasbrouck Mountain. Gold-silver mineralization is known to occur almost exclusively in the hangingwall of the Gold Zone-Kernick fault system in the Divide district. Many of the mineralized faults found in the hangingwall of the Gold Zone are WNW trending high angle faults which may have fed the basal Siebert tuff unit. Interestingly Erdman (1992) noted a 'NW striking (more westerly?) gold bearing silicified fault was mapped that offset the Divide lode at the south end of the Falcon Pit'. This further suggests that at least some Gold Mountain mineralization occurred after the Divide fault ceased its right lateral motion.
AlterationHost rocks have been affected by minor silicification, sericitization, oxidation, pyritization with potassic, phyllic, and propylitic alteration zones around faults and fractures.
Economic & production
Development statusProducer
First production1918
Last production1980
Discovery year1901
Identification
Deposit ID10310345
MRDS IDM242087
Alternate namesDivide Mine, Tonopah Divide Mine, Gold Mountain, Gold Hill Mine, Falcon Exploration Mine and Mill
RegionNA
Data scoreA
Coordinates37.99688, -117.24008
References
Albers, J.P. and Stewart, J.H., 1972, Geology and Ore Deposits of Esmeralda County, NV; NBMG Bull. 78.Knopf, Adolph, 1921, The Divide Silver District, Nevada; USGS Bull. 715, p. 147-170.State Inspector of Mines, 1981, Directory of Nevada Mine Operations Active in Calendar Year 1981NBMG Report 33, p. 124.Garside, L.J. and Tingley, J.V., 1982, Field Examination, NBMG, 26 Mar 82NBMG Bull 92, p. 121-128Smith, A.M., and Carpenter, Jay, 1931, Unpublished notes on inspection trip to Tonopah Divide Mine; NBMG File 87, item 1.The Mining Record Newspaper, Aug. 26, 1981, "Falcon Exploration Reopens Nevada Gold Hill Mine."Tonopah Times Bonanza, Aug. 6, 1981The Northern Miner, 1980.Tonopah Times Bonanza, Oct 25, 1974.Eureka Sentinel, 1972.Weed, W.H., Ed., 1920, The Mines Handbook, Vol XIV, p. 1162-1164Long, 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.http://www.tonogold.com/s/TonopahDivide.asp