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

References