|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||The FL Feeder prospect is at an elevation of about 4,700 feet one mile east of the toe of the Eureka Glacier, in the SE1/4SE1/4 section 36, T. 18 S., R. 7 E., Fairbanks Meridian. It is in a tributary to locally named Landslide Creek (see figure 3 of Rose, 1966 [ADMM GR 20]).|
The rocks in the area of the FL Feeder prospect occur within a body of diorite, quartz diorite, and gabbro that intrude andesite, dacite, and graywacke (Rose, 1966 [ADMM GR 20, figure 3]). A quartz monzonite crops out to the south of the gabbro body. The gabbroic body is possibly a sill (Nokleberg and others, 1991).The FL Feeder prospect consists of chalcopyrite- and pyrite-bearing hornblende-biotite gabbro breccia that trends southeasterly and cuts the enclosing gabbro at a high angle. The breccia is intensely amphibolitized and contains large porphyroblastic biotite crystals. The chalcopyrite and pyrite occur in clasts and matrix of the breccia. Samples of breccia assay as much as 1.1 percent copper, 0.1 percent nickel, 10 parts per million silver, and 192 parts per billion gold (W.T. Ellis, written communication, 1996).
|Geologic map unit||(-146.308264568299, 63.3044757113299)|
|Mineral deposit model||Ni-Cu-PGE in differentiated mafic-ultramafic sill.|
|Age of mineralization||Late Triassic, the age of the host rock.|
|Alteration of deposit||Secondary amphibole and biotite are strongly developed in the FL Feeder breccia.|
|Workings or exploration||The prospect is on active Fort Knox Gold Resource 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||6/18/2001|