The Bob is a zinc, lead, and silver mine located in Alaska.
About the MRDS Data:
All mine locations were obtained from the USGS Mineral Resources Data System. The locations and other information in this database have not been verified for accuracy. It should be assumed that all mines are on private property.
Mine Info
Bob MRDS details
Site Name
Primary: Bob
Commodity
Primary: Zinc
Primary: Lead
Primary: Silver
Location
State: Alaska
District: Chandalar
Land Status
Not available
Holdings
Not available
Workings
Not available
Ownership
Not available
Production
Not available
Deposit
Record Type: Site
Operation Category: Occurrence
Operation Type: Unknown
Years of Production:
Organization:
Significant:
Physiography
Not available
Mineral Deposit Model
Model Name: Skarn Zn-Pb
Orebody
Not available
Structure
Not available
Alterations
Alteration Type: L
Alteration Text: Calc-silicate.
Rocks
Not available
Analytical Data
Not available
Materials
Ore: Galena
Ore: Sphalerite
Comments
Comment (Exploration): Status = Inactive
Comment (Geology): Geologic Description = The Bob prospect is one of several Pb-Zn-Ag plus or minus Cu prospects near this site (DeYoung, 1978). Information specific to the property is sparse and only describes the prospect as galena and sphalerite with silver values in skarn associated with limestone (Grybeck, 1977). Newberry and others (1997) include the Bob prospect in a group of calcic Zn-Pb skarns and replacement bodies. These Zn-Pb skarns are described by Newberry and others (1986) as distal to Devonian(?) porphyry Cu-Mo systems associated with the Horace Mountain plutons in the Chandalar copper belt. The bedrock near of the prospect is mapped as Devonian Hunt Fork Shale near its contact with Skajit Limestone (Brosgi and Reiser, 1964). Intercalated diorite sills and andesitic flows(?) are also present in the section.
Comment (Workings): Workings / Exploration = Claims were located in 1972 and 1976 by Placid Oil. No other information is available.
Comment (Geology): Age = Devonian based on reported Early Devonian Pb/Pb zircon ages from the associated Baby Creek batholith and Horace Mountain plutons (Dillon and others, 1996).
Comment (Deposit): Model Name = Zn-Pb skarn deposits(?) (Cox and Singer, 1986; model 18c)
Comment (Deposit): Other Comments = See also: Bibban prospect (CH090). Alaska Kardex No. 031-61A (Kardex is a card file mining claim information system located at the State of Alaska DNR Public Information Center in Fairbanks).
Comment (Reference): Primary Reference = Grybeck, 1977
References
Reference (Deposit): Newberry, R.J., Allegro, G.L., Cutler, S.E., Hagen-Levelle, D.D., Adams, D.D., Nicholson, L.C., Weglarz, T.B., Bakke, A.A., Clautice, K.H., Coulter, G.A., Ford, M.J., Myers, G.L., and Szumigala, D.J., 1997, Skarn deposits of Alaska, in Goldfarb, R.J., and Miller, L.D., eds., Mineral Deposits of Alaska: Economic Geology Monograph 9, p. 355-395.
Reference (Deposit): Grybeck, D.J., 1977, Known mineral deposits of the Brooks Range, Alaska: US Geological Survey Open-File Report 77-166C, 41 p., 1 sheet, scale 1:1,000,000.
Reference (Deposit): Cobb, E.H., and Cruz, E.L., 1983, Summaries of data and lists of references to metallic and selected nonmetallic mineral deposits in the Chandalar quadrangle, Alaska: U.S. Geological Survey Open-File Report 83-278, 91 p.
Reference (Deposit): Newberry, R.J., Dillon, J.T., and Adams, D.D., 1986, Regionally metamorphosed calc-silicate-hosted deposits of the Brooks Range, northern Alaska: Economic Geology, v. 81, p. 1728-1752
Reference (Deposit): DeYoung, J.H., Jr., 1978, Mineral resources map of the Chandalar quadrangle, Alaska: U.S. Geological Survey Miscellaneous Field Studies Map MF-878-B, 2 sheets, scale 1:250,000.
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