Yellowstone Prospect, Thunder Mountain, Dall Island, Ketchikan Mining District, Prince of Wales-Hyder Census Area, Alaska, USAi
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Latitude & Longitude (WGS84):
55° 5' 20'' North , 133° 10' 12'' West
Latitude & Longitude (decimal):
Type:
Köppen climate type:
Location: The Yellowstone prospect is at an elevation of about 2,200 feet, about 0.6 mile north of peak 2750 on Thunder Mountain and about 0.3 mile southwest of the center of section 23, T. 78 S., R. 81 E.
Geology: The Yellowstone prospect was located prior to 1910 (Knopf, 1910, 1911; Berg and Cobb, 1967) but little work has been done on it since. When examined by D. J. Grybeck (unpublished field notes, 1984) and by Maas and others (1991,1995), the workings were several small, prominent, prospect pits and one short adit. The deposit consists of several small pods of hornfels and skarn in limestone interbedded with chert and argillite. The limestone is cut by several prominent diabase dikes that probably are not related to the mineralization. The hornfels and skarn on the dumps contain abundant chalcopyrite and pyrrhotite; pyrite is also present, and on one dump, sphalerite. Selected samples (D.J. Grybeck, unpublished analyses, 1984) contained up to 30 parts per million (ppm) silver, 2 percent copper, and 1,000 ppm zinc. Samples collected by Maas and others (1991) contained up to 7.89 percent zinc, 1.8 percent copper, and 11 ppm silver. Gold values were barely above the detection level of 5 parts per billion. The prospect is in a thrust plate of Silurian Heceta Limestone that overlies sedimentary rocks of the Descon Formation of Silurian and Devonian age (Eberlein and others, 1983; Brew, 1996).
Workings: The only workings are several small prospect pits and a short adit that date from before 1910.
Age: Silurian or younger.
Commodities (Major) - Ag, Cu, Zn; (Minor) - Au
Development Status: None
Deposit Model: Ag-Cu-Zn skarn (Cox and Singer, 1986; models 18b or 18c).
Select Mineral List Type
Standard Detailed Gallery Strunz Chemical ElementsCommodity List
This is a list of exploitable or exploited mineral commodities recorded at this locality.Mineral List
4 valid minerals.
Detailed Mineral List:
| ⓘ Chalcopyrite Formula: CuFeS2 |
| ⓘ Pyrite Formula: FeS2 |
| ⓘ Pyrrhotite Formula: Fe1-xS |
| ⓘ Sphalerite Formula: ZnS |
Gallery:
List of minerals arranged by Strunz 10th Edition classification
| Group 2 - Sulphides and Sulfosalts | |||
|---|---|---|---|
| ⓘ | Sphalerite | 2.CB.05a | ZnS |
| ⓘ | Chalcopyrite | 2.CB.10a | CuFeS2 |
| ⓘ | Pyrrhotite | 2.CC.10 | Fe1-xS |
| ⓘ | Pyrite | 2.EB.05a | FeS2 |
List of minerals for each chemical element
| S | Sulfur | |
|---|---|---|
| S | ⓘ Chalcopyrite | CuFeS2 |
| S | ⓘ Pyrite | FeS2 |
| S | ⓘ Pyrrhotite | Fe1-xS |
| S | ⓘ Sphalerite | ZnS |
| Fe | Iron | |
| Fe | ⓘ Chalcopyrite | CuFeS2 |
| Fe | ⓘ Pyrite | FeS2 |
| Fe | ⓘ Pyrrhotite | Fe1-xS |
| Cu | Copper | |
| Cu | ⓘ Chalcopyrite | CuFeS2 |
| Zn | Zinc | |
| Zn | ⓘ Sphalerite | ZnS |
Other Databases
| Link to USGS - Alaska: | CR138 |
|---|
Other Regions, Features and Areas containing this locality
North America PlateTectonic Plate
- Alexander DomainDomain
- Alexander TerraneVolcanic Arc
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