Description
Homestake Mining Co.
Commodities
PrimarySilver, Gold
SecondaryMercury
TertiaryAntimony, Arsenic, Titanium, Metal, Tungsten, Boron-Borates
Commodity typeB
Deposit
Model104: Hot-spring Au-Ag
Deposit sizeY
Ore controlFractures May Have Focused Hydrothermal Fluid Flow And Provided Open-Space Collection Areas For Exsolved Gaseous Phases.
Materials
Ore mineralsCinnabar, Stibnite
GangueBarite, Calcite, Dolomite, Marcasite, Pyrite
Geology
Host rockMudstone,Siltstone,Conglomerate
Associated rockPumice,Andesite,Basalt
StructureMajor Regional Subduction Fault Boundary Dividing The Franciscan Ophiolite Melange Of The Coast Ranges From The Upper Jurassic Marine Sediments Of The Great Valley Forearc Basin. Fault Consists Of 300-800 Ft. Wide Zone Of Cataclasite And Slikentite. Fault Dips Ne 45 In The Mine Area., Hydrothermal Explosion Breccias, Hydraulically Fractured Rock Masses, Crackle Breccias, Clastic Dikes, And Chalcedony-Quartz Vein Stockwork.
AlterationComplex And Overlapping; Argillic Zones, Sporadic Alunite Nodules, Chlorite-Montmorillonite-Celadonite Assemblages. Pervasive Adularia Replacement In Hanging Wall. Irregular Zone Of Silica-Carbonate Alteration Parallels The Precious Metals System Within The Footwall.
Economic & production
Development statusProducer
First production1985
Discovery year1978
Identification
Deposit ID10085020
MRDS IDW700452
RegionNA
Data scoreB
Coordinates38.4435, -122.383
References
ENGINEERING AND MINING JOURNAL, JUNE, 1988, P. 43.MINING MAGAZINE, JAN., 1988, P. 50.LEHRMAN, NORMAN J., 1986, THE MCLAUGHLIN MINE NAPA AND YOLO COUNTIES, CA.: NBMG REPORT 41 P. 85-89.