|Quadrangle map, 1:250,000-scale||TR|
|Quadrangle map, 1:63,360-scale||A-6|
|Nearby scientific data||Find additional scientific data near this location|
|Location and accuracy||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.|
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).
|Geologic map unit||(-133.932542748701, 58.0744696348483)|
|Mineral deposit model||Possible volcanogenic Mn (Cox and Singer, 1986; model 24c)|
|Mineral deposit model number||24c|
|Alteration of deposit||Jasperoid may represent local silicification (Pittman, 1957).|
|Workings or exploration||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).|
|Indication of production||None|
Cobb, E.H., 1978, Summary of references to mineral occurrences (other than mineral fuels and construction materials) in the Sumdum and Taku River quadrangles, Alaska: U.S. Geological Survey Open-File Report 78-698, 64 p.
Pittman, T.L., 1957, Reconnaissance examination of Sunrise Canyon manganese, Slocum Inlet, Alaska: U.S. Bureau of Mines Open-File Report 57, 7 p.
Redman, E.C., Roberts, W.S., Clough, A.H., and Kurtak, J.M., 1986, Preliminary mine, prospect, and sample location maps and descriptions, Juneau gold belt area: U.S. Bureau of Mines Open-File Report 85-86, 68 p., 4 sheets, scale 1:250,000.
Roehm, J.C., 1943, Strategic and critical mineral occurrences in southeastern Alaska: Alaska Territorial Department of Mines Miscellaneous Report 191-5, 98 p., 11 sheets.
|Reporters||J.C. Barnett and L.D. Miller (Juneau, Alaska)|
|Last report date||11/27/2001|