| Main commodities | Ag; Cu |
|---|---|
| Other commodities | Co |
| Ore minerals | chalcopyrite; pyrite; pyrrhotite |
| Gangue minerals | quartz |
| Quadrangle map, 1:250,000-scale | SK |
|---|---|
| Quadrangle map, 1:63,360-scale | A-2 |
| Latitude | 59.15 |
| Longitude | -135.72 |
| Nearby scientific data | Find additional scientific data near this location |
| Location and accuracy | This occurrence is at an elevation of about 5,000 feet about 3.7 miles, S87W from triangulation station 'Bow' on the west side of Chilkat Inlet. It is in the SW1/4, section 25, T. 31 S., R. 58 E. of the Copper River Meridian and is in a narrow septum of rock between two unnamed ice fields. The location corresponds to location 68 of Gilbert (1988). |
Geologic descriptionGilbert (1988) collected four rock samples described as, 'skarn with pyrrhotite (60%) and chalcopyrite', 'gossan with pyrrhotite', 'black schist with pyrrhotite (20%)', and 'quartz with pyrite in shear'. The samples contain up to 4.6 ppm silver, 5,950 ppm copper, and 95 ppm cobalt. The host rocks are mafic Paleozoic metavolcanics and metasediments that include argillaceous marble. Cretaceous medium-grained hornblende diorite and foliated granodiorite are nearby (Gilbert, 1988). The mineralization is probably the same age as the nearby Cretaceous intrusive rocks. | |
| Geologic map unit | (-135.721850605768, 59.1496575925271) |
|---|---|
| Mineral deposit model | Copper skarn? (Cox and Singer, 1986: model 18b?) |
| Mineral deposit model number | 18b? |
| Age of mineralization | The age is inferred to be Cretaceous based upon the Cretaceous age of nearby intrusive rocks (Gilbert, 1988). |
| Alteration of deposit | Skarn. |
| Indication of production | None |
|---|
| MRDS Number | 10308239 |
|---|---|
References | |
| Reporters | T.C. Crafford (T. Crafford & Associates, Anchorage) |
| Last report date | 2/4/2001 |