Sunrise Prospect, Juneau Mining District, Juneau, Alaska, USAi

Regional Level Types
Sunrise Prospect	Prospect
Juneau Mining District	Mining District
Juneau	City Borough
Alaska	State
USA	Country

Location: The Sunrise manganese prospect is at an elevation of about 3,000 feet, about 2.3 miles northeast of Arthur Peak. It is near the northwest corner of section 11, T. 44 S., R. 70 E. of the Copper River Meridian. This is location T012 of Wells and others (1986). The location is accurate within 1/4 mile.
Geology: The Sunrise manganese prospect consists of several outcrops of short manganese-bearing veins that are 1.0 to 3.5 feet wide, composed of about 70% rhodochrosite, 15% manganese dioxide (pyrolusite and/or manganite), 10% quartz, 5% rhodonite, and possibly some psilomelane (Wells and others, 1986). Several other parallel manganese-bearing veins 0.1 to 1.0 ft wide have been identified over a strike length of 6000 feet. The manganese-bearing veins are in a 200- to 300-foot section of phyllite that is overlain by schistose basalt and tuff. The veins are conformable to the phyllite which strikes N 50 W and dips 45-80 NE (Pittman, 1957). Pittman (1957) describes jasperoid at this prospect that may represent local silicification. A channel sample 3.5 feet long contain 22.4% manganese; another over 1 foot long contain 31.6% manganese (Pittman, 1957). Roehm (1943) reported that assays of several samples of low-grade and high-grade veins vary from 10.76% to 38.45% manganese. A beneficiation test in 1957 by the U.S. Bureau of Mines produced a 40.6% manganese concentrate (Pittman, 1957). The beneficiation test failed to produce a marketable concentrate (Cobb, 1978 [OFR 78-698]). Development consists of a few shallow pits and trenches. The prospect was discovered by Henry 'Tiger' Olson in 1935 (Redman and others, 1985). There were active claims on the property from 1935 to 1979 (Wells and others, 1986).
Workings: Development consists a few shallow pits and trenches. The prospect was discovered by Henry 'Tiger' Olson in 1935 (Redman and others, 1985). There were active claims on the property from 1935 to 1979 (Wells and others, 1985).
Alteration: Jasperoid may represent local silicification (Pittman, 1957).

Commodities (Major) - Mn
Development Status: No
Deposit Model: Possible volcanogenic Mn (Cox and Singer, 1986; model 24c)

Other Databases

Link to USGS - Alaska:	TR015

Other Regions, Features and Areas containing this locality

References