Unnamed (head of Blowback Creek)

Occurrence, Inactive

Commodities and mineralogy

Main commodities Ag; Au; Cu
Other commodities As; Bi; Fe; Mn
Gangue minerals siderite

Geographic location

Quadrangle map, 1:250,000-scale TN
Quadrangle map, 1:63,360-scale A-2
Latitude 65.03814
Longitude -150.72874
Nearby scientific data Find additional scientific data near this location
Location and accuracy This occurrence is at an elevation of about 1,500 feet on the toe of a northwest-trending ridge at the head of Blowback Creek, and approximately 1.1 miles northeast of Manley Hot Springs Dome. The site is at Alaska Division of Geological and Geophysical Surveys (ADGGS) sample station 97SL086 (Liss and others, 1998), near the southwest corner of section 36, T. 3 N., R. 16 W., of the Fairbanks Meridian. The location is accurate within 500 feet.

Geologic setting

Geologic description

Bedrock at the head of Blowback Creek is mainly Lower Cretaceous sandstone, shale, and siltstone, along with less-abundant quartzite (Reifenstuhl and others, 1998). The northwestern contact of the Tertiary Hot Springs granite pluton and its hornfels aureole is 3,000 feet to the south.
A sample (97SL086) of quartzite with siderite collected by ADGGS on a ridge at the head of Blowback Creek contained 2,720 parts per billion (ppb) gold, 33.8 parts per million (ppm) silver, 256 ppm arsenic, 480 ppm bismuth, 8,740 ppm copper, 3,400 ppm manganese, and more than 15 percent iron (Liss and others, 1998). There has been extensive exploration by industry around Hot Springs Dome and at the Barrett prospect (TN103).
Geologic map unit (-150.731209531952, 65.037647934509)
Mineral deposit model Polymetallic veins (Cox and Singer, 1986; model 22c).
Mineral deposit model number 22c
Age of mineralization Tertiary. The granite has a [whole-rock?] K-Ar age date of 62 +/- 3 Ma (Chapman and others, 1982), and a biotite 40Ar/39Ar age date of 59 +/- 0.8 Ma (Reifenstuhl and others, 1998).

Production and reserves

Workings or exploration A sample (97SL086) of quartzite with siderite collected by ADGGS on a ridge at the head of Blowback Creek contained 2,720 parts per billion (ppb) gold, 33.8 parts per million (ppm) silver, 256 ppm arsenic, 480 ppm bismuth, 8,740 ppm copper, 3,400 ppm manganese, and more than 15 percent iron (Liss and others, 1998). There has been extensive exploration by industry around Hot Springs Dome and at the Barrett prospect (TN103).
Indication of production None

References