|Quadrangle map, 1:250,000-scale||SM|
|Quadrangle map, 1:63,360-scale||A-1|
|Nearby scientific data||Find additional scientific data near this location|
|Location and accuracy||This occurrence is near the top of the isolated knob, hill 1333, about 0.7 mile south-southeast of lake 780. The occurrence is about 0.4 mile east-northwest of the center of section 16, T. 11 N., R. 38 W., of the Seward Meridian. The location is accurate.|
Geologic descriptionThis occurrence is a zone of hematite-rich quartz veins in fine-grained hornfels derived from what has been mapped as the Upper Cretaceous Kuskokwim Group (Cady and others, 1955; LePain and others, 2000). The protolith might also be the Kahiltna assemblage (Wilson and others, 1998). A high level, aphanitic rhyolite intrusive body underlies the hornfels (M. L. Miller, unpublished field data, 1999). Hematite locally makes up a large percentage of the quartz vein. Three grab samples collected of the hematite-rich quartz vein contained up to 2.88 parts per million (ppm) cadmium, 795 ppm zinc, and 14.5 ppm tungsten (M. L. Miller, unpublished analytical data, 1999).
|Geologic map unit||(-156.019081238369, 61.0446602913031)|
|Age of mineralization||Unknown. The rhyolite body under this occurrence has a 40Ar/39Ar age of 67 Ma (R. Wilson, oral communication, 2003).|
|Alteration of deposit||Hematite replacement in hornfels.|
|Workings or exploration||The U.S. Geological Survey sampled the site in 1999.|
|Indication of production||None|
Cady, W.M., Wallace, R.E., Hoare, J.M., and Webber, E.J., 1955, The central Kuskokwim region, Alaska: U.S. Geological Survey Professional Paper 268, 132 p.
LePain, D.L., Blodgett, R.B., Clough, J.G., Ryherd, T.J., and Smith, T.N., 2000, Generalized stratigraphy and petroleum potential of the Holitna region, southwest Alaska: Alaska Division of Geological & Geophysical Surveys Preliminary Interpretive Report 2000-1, 34 p., 1 sheet, scale 1:250,000.
|Reporters||T.K. Bundtzen (Pacific Rim Geological Consulting, Inc.) and M.L. Miller (U.S. Geological Survey)|
|Last report date||5/9/2003|