Unnamed Occurrences (ARDF - TN105; Hot Springs Dome; east Barrett), Hot Springs Mining District, Yukon-Koyukuk Census Area, Alaska, USAi

Regional Level Types
Unnamed Occurrences (ARDF - TN105; Hot Springs Dome; east Barrett)	- not defined -
Hot Springs Mining District	Mining District
Yukon-Koyukuk Census Area	Census Area
Alaska	State
USA	Country

Location: These occurrences are at and near the summit of Manley Hot Springs Dome. The area of occurrences ranges in elevation from 2,100 to 2,649 feet, and extends for about 1,750 feet in a north-south direction and 2,250 feet in an east-west direction. The site is about at the center of this area, at Alaska Division of Geological and Geophysical Surveys (ADGGS) sample station 97RN144, at the summit of Manley Hot Springs Dome (Liss and others, 1998). The location is accurate within 500 feet.
Geology: The country rocks in the area of Hot Springs Dome consist of Tertiary biotite granite, Cretaceous, predominantly marine, clastic sedimentary rocks, and a zone of contact-metamorphosed sedimentary rocks (hornfels) peripheral to the granite (Chapman and others, 1982; Reifenstuhl and others, 1998). The hornfels zone is approximately 1/4 mile wide. Dikes ranging from 3 inches to 4 feet thick cut the granite (Waters, 1934). Most of the dikes contain tourmaline, in amounts ranging from less than 1 percent to 15 percent; monazite was also identified in one specimen. Rock samples were collected in 1998 by ADGGS at the summit, and along spur ridges, of Manley Hot Springs Dome (Liss and others, 1998). Samples from the summit, and from up to 1,250 feet north, 1,000 feet west, 1,250 feet east, and 500 feet south of the summit, probably are on eastern extensions of the shear zones that host mineralization at the Barrett prospect (TN103). Samples of goethite-bearing, siderite-bearing, and manganese-stained gossan; of breccia; and of galena-bearing and other mineralized rocks contained one or more of the following maximum geochemical values: 1,500 parts per billion (ppb) gold, 98.4 parts per million (ppm) silver, 2,080 ppm arsenic, 2,760 ppm bismuth, 497 ppm cobalt, 6,090 ppm copper, 980 ppm phosphorous, 7.81 percent lead, 38 ppm antimony, 130 ppm tungsten, 8,510 ppm zinc, and more than 15 percent iron and 10,000 ppm manganese.
Workings: Rock samples were collected in 1998 by ADGGS at the summit, and along spur ridges, of Manley Hot Springs Dome (Liss and others, 1998). Samples from the summit, and from up to 1,250 feet north, 1,000 feet west, 1,250 feet east, and 500 feet south of the summit, probably are on eastern extensions of the shear zones that host mineralization at the Barrett prospect (TN103). Samples of goethite-bearing, siderite-bearing, and manganese-stained gossan; of breccia; and of galena-bearing and other mineralized rocks contained one or more of the following maximum geochemical values: 1,500 parts per billion (ppb) gold, 98.4 parts per million (ppm) silver, 2,080 ppm arsenic, 2,760 ppm bismuth, 497 ppm cobalt, 6,090 ppm copper, 980 ppm phosphorous, 7.81 percent lead, 38 ppm antimony, 130 ppm tungsten, 8,510 ppm zinc, and more than 15 percent iron and 10,000 ppm manganese.
Age: 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).

Commodities (Major) - Ag, Au, Cu, Pb, Zn; (Minor) - As, Bi, Co, Fe, Mn, Sb, W
Development Status: None
Deposit Model: Polymetallic veins (Cox and Singer, 1986; model 22c).

Other Databases

Link to USGS - Alaska:	TN105

Other Regions, Features and Areas containing this locality

References