|Quadrangle map, 1:250,000-scale||TK|
|Quadrangle map, 1:63,360-scale||D-4|
|Nearby scientific data||Find additional scientific data near this location|
|Location and accuracy||This site is a 1.5-mile-long, northeast-trending area of mineral occurrences near the headwaters of Portage Creek. The center of the area is at an elevation of about 3,700 feet, in the NE1/4NW1/4 sec. 26, T. 22 S., R. 7 W., Fairbanks Meridian. The location is accurate.|
Geologic descriptionThe occurrences at the southwest end of the area are quartz-veined, mafic(?), aphanitic and hornfelsed volcanic rocks and rusty weathering argillite; at the northeast end, they are brecciated tuffs(?) (J. Schmidt, written communication, 2001). Samples of the hornfelsed volcanic rocks contain 260 parts per million copper, 0.5 part per million gold, 0.4 part per million silver, and 0.27 part per million mercury. Argillite samples contain 1 part per million silver; and the breccia contains 0.4 part per million silver and 215 parts per million copper. (The 0.5-part-per-million gold value is an ICP analysis from XRAL Laboratories; a fire assay of the same sample gives less than 0.005 part per million gold. The cause of the discrepancy is not known.)
|Geologic map unit||(-148.837759070278, 62.9843290421398)|
|Alteration of deposit||Iron-oxide alteration.|
|Workings or exploration||Only surface sampling by U.S. Geological Survey (J. Schmidt, written communication, 2001).|
|Indication of production||None|
Additional commentsMAS/MILS number 20760109.
Csejtey, Bela, Jr., Nelson, W.H., Jones, D.L., Silberling, N.J., Dean, R.M., Morris, M.S., Lanphere, M.A., Smith, J.G., and Silberman, M.L, 1978, Reconnaissance geologic map and geochronology, Talkeetna Mountains quadrangle, northern part of Anchorage quadrangle, and southwest part of Healy quadrangle, Alaska: U.S. Geological Survey Open-File Report 78-558-A, 60 p., 1 sheet, scale 1:250,000.
|Reporters||R.K. Rogers (U. S. Geological Survey contractor)|
|Last report date||10/4/2002|