Unnamed (near Hoosier Creek)

Occurrences, Inactive

Commodities and mineralogy

Main commodities Au
Other commodities As
Ore minerals pyrite; sulfides
Gangue minerals carbonate; quartz; siderite

Geographic location

Quadrangle map, 1:250,000-scale TN
Quadrangle map, 1:63,360-scale B-1
Latitude 65.42057
Longitude -150.04185
Nearby scientific data Find additional scientific data near this location
Location and accuracy This occurrence is near the junction of Fortyseven Pup and Hoosier Creek and represents one of 3 mineralized bedrock samples along a 2-mile stretch of Hoosier Creek. The site represents Alaska Division of Geological and Geophysical Surveys (ADGGS) sample station 96KC225 (Reifenstuhl and others, 1997 [PDF 97-29h]), near the midpoint of Hoosier Creek, and is in the northwest quarter of section 21, T. 7 N., R. 12 W., of the Fairbanks Meridian. The location is accurate. The site is included in location 48 of Cobb (1972).

Geologic setting

Geologic description

Hoosier Creek drains an area underlain by Cambrian or upper Proterozoic quartzite, feldspathic quartzite, grit, calcareous siltstone, limestone, and chert, and by Triassic Rampart Group gabbro and diabase, and intermediate igneous rocks, chert, and tuff (Reifenstuhl and others, 1997 [RI 97-15a]).
Diabase bedrock in Hoosier Creek contains quartz veins up to 18 inches wide, and pyrite is disseminated in the adjacent rock (Hess, 1908). White mica from a similar vein one mile north of this location yielded an Ar/Ar age of 72.2 +/- 0.3 Ma (Reifenstuhl and others, 1997 [PDF 97-29h]). A sample of Rampart Group altered gabbro (96KC225), with sulfides and quartz-carbonate-siderite veins, contained no anomalous elements; another gabbro sample (96KC230), with calcite veins and a trace of disseminated chalcopyrite, contained 160 parts per million (ppm) copper (Liss and others, 1997). A sample (96RN202) of a nearby altered granite dike with minor disseminated sulfides contained 27 parts per billion gold and 1,690 ppm arsenic.
Geologic map unit (-150.044364643356, 65.4201005240119)
Mineral deposit model Low-sulfide Au-quartz veins? (Cox and Singer, 1986; model 36a?).
Mineral deposit model number 36a?
Age of mineralization White mica from a similar vein one mile north of this location yielded an Ar/Ar age of 72.2 +/- 0.3 Ma (Reifenstuhl and others, 1997 [PDF 97-29h]).

Production and reserves

Workings or exploration A sample of Rampart Group altered gabbro (96KC225), with sulfides and quartz-carbonate-siderite veins, contained no anomalous elements; another gabbro sample (96KC230), with calcite veins and a trace of disseminated chalcopyrite, contained 160 parts per million (ppm) copper (Liss and others, 1997). A sample (96RN202) of a nearby altered granite dike with minor disseminated sulfides contained 27 parts per billion gold and 1,690 ppm arsenic. There is no record of exploration by industry at these occurrences.
Indication of production None

References