|Quadrangle map, 1:250,000-scale||DN|
|Quadrangle map, 1:63,360-scale||C-1|
|Nearby scientific data||Find additional scientific data near this location|
|Location and accuracy||The Bloom prospect is on a north-facing cliff on the south bank of Canyon Creek, about 500 feet below the mouth of the North Fork. The location is accurate within 500 feet. The prospect is occurrence 103 of Thornsberry, McKee, and Salisbury (1984).|
Geologic descriptionThe country rocks at the Bloom prospect are interlayered, thinly- laminated and locally graphitic black quartzite and thinly-laminated tan quartzite. The rocks are sheared subparallel to their foliation (Thornsberry, McKee, and Salisbury, 1983, occurrence 103). The graphitic units are thickly coated with yellow to white sulfate(?), a common indicator of pyrite in unweathered rock. In 1983, the U.S. Bureau of Mines collected several samples at the site, but assays showed no significant concentrations of valuable metals. Gold and silver were not determined. Antimony values ranged from 6 to 30 ppm (Thornsberry, McKee, and Salisbury, 1984, v. 2).
|Geologic map unit||(, )|
|Mineral deposit model||Possible stratabound sulfide occurrences in graphitic layers of Birch Creek Schist.|
|Age of mineralization||Holocene weathering of Precambrian country rocks.|
|Alteration of deposit||Extensive surface development of secondary sulfates.|
|Workings or exploration||Workings consist of a 3- by 3- foot pit (adit-cut).|
|Indication of production||None|
Additional commentsThe prospect is in Denali National Park and Preserve.
Thornsberry, V. V., McKee, C. J., and Salisbury, W. G., eds, 1984, 1983 Mineral Resource Studies: Kantishna Hills and Dunkle Mine Areas, Denali National Park and Preserve, Alaska: U. S. Bureau of Mines Open-File Report 129-84. 3 Volumes: v. 1, Text; v. 2, Appendices; v. 3, Maps. Prepared by Salisbury & Dietz, Inc., Spokane, WA.
|Last report date||12/26/2000|