|Quadrangle map, 1:250,000-scale||DE|
|Quadrangle map, 1:63,360-scale||D-1|
|Nearby scientific data||Find additional scientific data near this location|
|Location and accuracy||The Ranger prospect is at an elevation of about 500 feet, 1.3 miles south to south-southeast from southeast tip of Tah Island. It is about 0.4 mile northwest of the center of section 29, T. 81 S., R. 88 E. The location is accurate.|
A major fault in the area juxtaposes sandstone of the Devonian Karheen Formation to the west against Ordovician diorite to the east (Gehrels, 1992). In 1918, Chapin described the Ranger prospect as an outcrop of magnetite up to 25 feet across that locally contains chalcopyrite. The country rock is greenstone (probably fine-grained granodiorite or volcanic rock), tuff, volcanic breccia, graywacke, and grit; the greenstone is cut by many granitic dikes and quartz veins.The prospect was restaked in the early 1950s. Glover (1954 [MI 121-1]) describes the deposit as a body of magnetite about 10 by 15 feet in outcrop area. The original discovery, on which a short tunnel was driven early in the 20th century, was located about 100 feet north of the magnetite body staked in the 1950s. Glover also found several other lenses and pods of magnetite in greenstone, none of which was of substantial size. He found no chalcopyrite in any of the magnetite bodies. The greenstone porphyry in the vicinity is mildly radioactive, averaging about 0.005 percent eU.
|Geologic map unit||(-132.304655598605, 54.8210585749276)|
|Mineral deposit model||Chalcopyrite? in magnetite body.|
|Workings or exploration||The prospect was explored by a 10-foot adit and some surface clearing prior to 1918. A magnetite body nearby was restaked in the 1950s.|
|Indication of production||None|
Additional commentsThis prospect is in the South Prince of Wales Wilderness, which is closed to prospecting and mineral exploration.
Chapin, Theodore, 1918, Mining developments in the Ketchikan and Wrangell mining districts: U.S. Geological Survey Bulletin 662-B, p. 63-75
Cobb, E. H., 1972, Metallic mineral resources of the Dixon Entrance quadrangle, Alaska: U.S. Geological Survey Miscellaneous Field Studies Map MF-434, 1 sheet, scale 1:250,000.
Cobb, E. H., 1978, Summary of references to mineral occurrences (other than mineral fuels and construction materials) in the Dixon Entrance quadrangle, Alaska: U.S. Geological Survey Open-File Report 78-863, 34 p.
Gehrels, G. E., 1992, Geologic map of southern Prince of Wales Island, southeastern Alaska: U.S. Geological Survey Miscellaneous Investigations Series Map I-2169, 23 p., 1 sheet, scale 1:63,360.
|Reporters||D.J. Grybeck (Applied Geology)|
|Last report date||9/1/2003|