Main commodities | Ag; Cu |
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Ore minerals | azurite; chalcopyrite; malachite; pyrite |
Gangue minerals | actinolite; albite; chlorite; epidote; potassium feldspar; quartz; sericite |
Quadrangle map, 1:250,000-scale | MH |
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Quadrangle map, 1:63,360-scale | A-2 |
Latitude | 63.1239 |
Longitude | -144.9047 |
Nearby scientific data | Find additional scientific data near this location |
Location and accuracy | This occurrence is about 1.5 miles east-southeast of the junction of the Chistochina River and the West Fork Chistochina Rivers. The occurrence is about one-third mile east of the center of section 5, T. 21 S., R. 15 E., Fairbanks Meridian. It corresponds to locality 138 in table 2 of Nokleberg and others (1991), and the location is probably accurate to 0.2 mile. |
Geologic descriptionThis occurrence is in dacite porphyry of Early Permian age. The dacite intrudes the lower part of the Slana Spur Formation of Pennsylvanian to Early Permian age; the Slana Spur Formation is mainly composed of dacite agglomerate. Locally, the dacite porphyry is intensely altered to a rock composed of actinolite, albite, chlorite, epidote, potassium feldspar, and sericite.
This occurrence is a dacite porphyry that contains disseminated pyrite and chalcopyrite and is locally stained with azurite and malachite. A grab sample assayed 1.14 percent copper and 50 parts per million silver (Nokleberg and others, 1991). The deposit is probably a porphyry copper related to the Early Permian dacite porphyry. | |
Geologic map unit | (-144.906920955354, 63.1234980856209) |
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Mineral deposit model | Probably Porphyry Cu (Cox and Singer, 1986; model 20c). |
Mineral deposit model number | 20c |
Age of mineralization | Probably Early Permian. |
Alteration of deposit | Locally intense alteration of dacite. Alteration minerals include actinolite, albite, chlorite, epidote, potassium feldspar, and sericite. |
Workings or exploration | Limited surface sampling; no workings reported from the site. |
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Indication of production | None |
Additional commentsMore prospecting appears to be warranted. |
References | |
Reporters | W.T. Ellis (Alaska Earth Sciences) and C.C Hawley (Hawley Resource Group) |
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Last report date | 7/9/2003 |