|Quadrangle map, 1:250,000-scale||MH|
|Quadrangle map, 1:63,360-scale||B-5|
|Nearby scientific data||Find additional scientific data near this location|
|Location and accuracy||This prospect is at an elevation of 4,400 feet in the headwaters of an unnamed west fork of Specimen Creek, in the NW1/4NE1/4 section 32, T. 18 S., R. 9 E., Fairbanks Meridian. The occurrence corresponds to localities 51 and 52 in table 2 of Nokleberg and others (1991).|
The rock at this occurrence consists of Upper Triassic olivine cumulate intruded by a metadiabase dike (Nokleberg and others, 1991). Rose (1965, figure 2) mapped a peridotite body in the headwaters of Specimen Gulch.The olivine cumulate contains disseminated chromite; sample 79CH010B assayed more than 5,000 parts per million chromium (Nokleberg and others, 1991). Malachite occurs along fractures in the metadiabase dike; grab sample 79CH010C of dike material contained 150 parts per billion gold.
|Geologic map unit||(-146.062262919191, 63.3173803618724)|
|Mineral deposit model||Disseminated chromite in ultramafic rocks; epigenetic? shear zone mineralization.|
|Age of mineralization||The chromite is Late Triassic, the presumed age of the ultramafic host rock. The copper and gold are Late Triassic or younger.|
|Alteration of deposit||Oxidation of copper mineral(s).|
|Workings or exploration||The occurrence is on active MAN Resources claims.|
|Indication of production||None|
Nokleberg, W.J., Lange, I.M., Roback, R.C., Yeend, Warren, and Silva, S.R., 1991, Map showing locations of metalliferous lode and placer mineral occurrences, mineral deposits, prospects, and mines, Mount Hayes quadrangle, eastern Alaska Range, Alaska: U.S. Geological Survey Miscellaneous Field Studies Map MF-1996-C, 42 p., 1 sheet, scale 1:250,000.
|Reporters||W.T. Ellis (Alaska Earth Science), C.C. Hawley (Hawley Resource Group), and W.J. Nokleberg (USGS)|
|Last report date||6/19/2001|