Unnamed (Bonanza-Rosa Ridge) (ARDF #TN038) Pb, Zn

Unnamed (Bonanza-Rosa Ridge)

Occurrence, Inactive

Commodities and mineralogy

Main commodities	Pb; Zn
Other commodities	As; Cr; Mn; Sb
Gangue minerals	quartz

Geographic location

Quadrangle map, 1:250,000-scale	TN
Quadrangle map, 1:63,360-scale	B-3
Latitude	65.36782
Longitude	-151.27702
Nearby scientific data	Find additional scientific data near this location
Location and accuracy	The Bonanza-Rosa Ridge lode occurrence is at an elevation of 2,600 feet on the divide at the heads of Bonanza and Rosa creeks, about 7 miles north of the Yukon River. The site is Alaska Division of Geological and Geophysical Surveys (ADGGS) sample station 92RE04 (Solie and others, 1993), in the northwest quarter of section 9, T. 6 N., R. 18 W., of the Fairbanks Meridian. This location is accurate within 1000 feet.

Geologic setting

Geologic description Bedrock in the vicinity of this occurrence is Paleozoic schist, quartzite, phyllite, and slate, and subordinate limestone, dolomite, greenstone, and chert (Chapman and others, 1982). The rocks are structurally complex. In 1992, the Alaska Division of Geological and Geophysical Surveys (ADGGS) investigated the Bonanza-Rosa Ridge area as part of a mineral resource evaluation of State-selected lands (Solie and others, 1993). Rocks collected in this area (at stations 92RE04 and 92MW418) included micaceous quartzite(?) and gossanous, quartzose calcareous semischist. A sample of the quartzite(?) contained 336 parts per million (ppm) lead and 151 ppm zinc; and a sample of the semischist contained 190 ppm arsenic, 22 ppm bismuth, 2,800 ppm chromium, 1,534 ppm manganese, and 10 ppm antimony (Solie and others, 1993).
Geologic map unit	(-151.279544159658, 65.3673182562129)
Mineral deposit model	Polymetallic veins? (Cox and Singer, 1986; model 22c?).
Mineral deposit model number	22c?

Production and reserves

Workings or exploration	Bedrock in the vicinity of this occurrence is Paleozoic schist, quartzite, phyllite, and slate, and subordinate limestone, dolomite, greenstone, and chert (Chapman and others, 1982). The rocks are structurally complex. In 1992, the Alaska Division of Geological and Geophysical Surveys (ADGGS) investigated the Bonanza-Rosa Ridge area as part of a mineral resource evaluation of State-selected lands (Solie and others, 1993). Rocks collected in this area (at stations 92RE04 and 92MW418) included micaceous quartzite(?) and gossaneous, quartzose calcareous semischist. A sample of the quartzite(?) contained 336 parts per million (ppm) lead and 151 ppm zinc; and a sample of the semischist contained 190 ppm arsenic, 22 ppm bismuth, 2,800 ppm chromium, 1,534 ppm manganese, and 10 ppm antimony (Solie and others, 1993).
Indication of production	None

Workings or exploration

Bedrock in the vicinity of this occurrence is Paleozoic schist, quartzite, phyllite, and slate, and subordinate limestone, dolomite, greenstone, and chert (Chapman and others, 1982). The rocks are structurally complex.

In 1992, the Alaska Division of Geological and Geophysical Surveys (ADGGS) investigated the Bonanza-Rosa Ridge area as part of a mineral resource evaluation of State-selected lands (Solie and others, 1993). Rocks collected in this area (at stations 92RE04 and 92MW418) included micaceous quartzite(?) and gossaneous, quartzose calcareous semischist. A sample of the quartzite(?) contained 336 parts per million (ppm) lead and 151 ppm zinc; and a sample of the semischist contained 190 ppm arsenic, 22 ppm bismuth, 2,800 ppm chromium, 1,534 ppm manganese, and 10 ppm antimony (Solie and others, 1993).

Indication of production

None

References

References Chapman, R.M., Yeend, W.E., Brosge, W.P., and Reiser, H.N., 1982, Reconnaissance geologic map of the Tanana quadrangle: U.S. Geological Survey Open-File Report 82-734, 20 p., scale 1:250,000. Solie, D.N., Wiltse, M.A., Harris, E.E., and Roe, J.T., 1993, Land selection unit 34 (Bettles & Tanana quadrangles): References, DGGS sample locations, geochemical and major oxide data: Alaska Division of Geological and Geophysical Surveys Public Data File 93-34, 41 pages, 1 sheet, scale 1:250,000.
Reporters	D.J. Szumigala (ADGGS)
Last report date	4/20/2004