|Quadrangle map, 1:250,000-scale||BR|
|Quadrangle map, 1:63,360-scale||B-2|
|Nearby scientific data||Find additional scientific data near this location|
|Location and accuracy||This occurrence is an outcrop at the base of Pink Bluff about 50 feet from the south bank of the Salmon Fork of Black River. It is about 0.2 mile downstream of the mouth of Runt Creek, in the SW1/4SW1/4 section 27 (almost on boundary with section 28), T. 19 N., R. 29 E., of the Fairbanks Meridian. The location is accurate within several hundred feet.|
Geologic descriptionSphalerite and galena occur in a gossan zone about 60 feet long and 2 feet wide in mottled pink and gray dolomite (K.H. Clautice, unpublished field data, 1992). A grab sample of massive galena veined with calcite assays 80.69 percent lead, and a sample of dense, brick-red gossan contains 18,557 ppm zinc (U.S. Bureau of Mines, 1995). Lead isotope ratios (Clough and others, 1993) are similar to those of Lower Cambrian (about 520 Ma) 'Older Carbonate'-hosted zinc-lead deposits in western Canada (Godwin and others, 1982). Dover (1994) maps the dolomite as part of the Lower Cambrian and Proterozoic, Tindir Group, which consists predominantly of carbonate, quartzite, argillite, and subordinate volcanic rocks. Stromatolites resembling those of the Pack Formation of the Tindir Group occur in the vicinity (Doyon Limited, 1977).
|Geologic map unit||(-141.523073283412, 66.4408368509455)|
|Mineral deposit model||Southeast Missouri Pb-Zn (Cox and Singer, 1986; model 32a)|
|Mineral deposit model number||32a|
|Age of mineralization||Lead isotope ratios (Clough and others, 1993) are similar to those of Lower Cambrian (about 520 Ma) 'Older Carbonate'-hosted zinc-lead deposits in western Canada (Godwin and others, 1982).|
|Alteration of deposit||Iron oxides.|
|Indication of production||None|
Brabb, E.E., 1970, Preliminary geologic map of the Black River quadrangle, east-central Alaska: U.S. Geological Survey Miscellaneous Geologic Investigations Map I-601, 1 sheet, scale 1:250,000.
Clough, J.G., Robinson, M.S., Clautice, K.H., and Blodgett, R.B., 1993, Evaluation of unit 35--Charley River and Black River quadrangles, east central Alaska; General geology, and geochemical, major oxide and lead isotope data: Alaska Division of Geological and Geophysical Surveys Public-Data File 93-35, 13 p., 1 sheet, scale 1:250,000.
Dover, J.H., 1994, Geology of part of east-central Alaska, in Plafker, George, and Berg, H.C., eds., The Geology of Alaska: Geological Society of America, p. 153-203.
Doyon Limited, 1977, Doyon Limited Report 77-02a, p. 7-19. (Report held by Doyon, Limited, Fairbanks, Alaska.)
Godwin, C.I., Sinclair, A.J., and Ryan, B.D., 1982, Lead-isotope models for the genesis of carbonate-hosted Zn-Pb, shale-hosted Ba-Zn-Pb, and silver-rich deposits in the northern Canadian Cordillera: Economic Geology, v. 77, p. 82-94.
|Reporters||K.H. Clautice (Alaska Division of Geological and Geophysical Surveys)|
|Last report date||3/14/2002|