Commodities
PrimaryGold
SecondaryPlatinum, Silver
Commodity typeM
Deposit
Deposit typeStream placer
Model119: Placer Au-PGE
Orebody formIrregular
Ore controlMechanical accumulation on irregular bedrock riffles and within river- and stream-channel lag gravels, bars, and point bar deposits
Materials
Ore mineralsGold
GangueQuartz, Magnetite, Ilmenite, Zircon, Pyrite, Amphibole, Epidote, Chlorite, Siderite
Geology
Host rockSand and Gravel
StructureGills Hill Fault, Foresthill Fault, Melones Fault Zone
Tectonic settingMagmatic arc
Economic & production
Development statusPast Producer
Discovery year1848
Identification
Deposit ID10310693
Alternate namesChalk Bluff District
RegionNA
Data scoreA
Coordinates39.20899, -120.89963
References
Clark, L. D., 1960, Foothills fault system, western Sierra Nevada, California: Geological Society of America Bulletin, v. 71, p. 483-496.Clark, W.B., 1970, Gold districts of California: California Division of Mines and Geology Bulletin 193, p. 131-132.Hobson, J.B. and Wiltsee, E.A., 1892, You Bet mining district: California State Mining Bureau Report 11, p. 317-318.Lindgren, W., 1900, Colfax Folio: U.S. Geological Survey Atlas of the U.S., Folio 66, 10 p.Lindgren, W., 1911, Tertiary gravels of the Sierra Nevada: U.S. Geological Survey Professional Paper 73, p. 144.Jarman, A., 1927, You Bet District: California State Mining Bureau Report 23, p. 99-100.MacBoyle, E., 1919, Nevada County: You Bet mining district: California State Mining Bureau Report 16, p. 63-66.Saucedo, G. J. and Wagner, D. L., 1992, Geologic map of the Chico Quadrangle: California Division of Mines and Geology Regional Map Series Map No. 7A, scale 1:250,000.Yeend, W.E., 1974, Gold-bearing gravel of the ancestral Yuba River, Sierra Nevada, California: U.S. Geological Survey Professional Paper 772, 44 p.