| Quadrangle map, 1:250,000-scale | CR |
|---|---|
| Quadrangle map, 1:63,360-scale | B-6 |
| Latitude | 55.45074 |
| Longitude | -133.8109 |
| Nearby scientific data | Find additional scientific data near this location |
| Location and accuracy | This occurrence is in a cliff face about 1.0 mile north-northeast of Cape Addington at the north end of a rocky beach. It is about 0.2 mile south of the center of section 14, T. 74 S., R. 76 E. |
Geologic descriptionThis occurrence is at the contact between Silurian Heceta Limestone and a Cretaceous quartz monzonite and granodiorite pluton (Clark, 1970 [OF 420]; D.J. Grybeck, unpublished field notes and analyses, 1984). The pluton extends south to Cape Addington. Patches of calc-silicate gneiss and hornfels less than a few tens of feet thick mark the contact; locally there is quartz veining. The contact is also copper stained in places and there are disseminated and scattered small masses of sulfides, including chalcopyrite, sphalerite, galena, and pyrite. Almost all of the sulfides are within 10 feet of the contact and the mineralization is sparse. Selected samples contain up to several percent copper and zinc, and up to 50 parts per million silver. | |
| Geologic map unit | (-133.812576391118, 55.4503775954895) |
|---|---|
| Mineral deposit model | Contact-metamorphic Ag-Cu-Zn deposit. |
| Age of mineralization | In the contact of a Cretaceous granitic pluton. |
| Alteration of deposit | Sparse skarn minerals at contact of granitic pluton and marble. |
| Workings or exploration | Only limited surface sampling during geologic mapping. |
|---|---|
| Indication of production | None |
| MRDS Number | A010173 |
|---|---|
References | |
| Reporters | D.J. Grybeck (Applied Geology) |
| Last report date | 5/1/2004 |