Congress Prospect, Chichagof Mining District (Chicagof Mining District), Sitka, Alaska, USAi
| Regional Level Types | |
|---|---|
| Congress Prospect | Prospect |
| Chichagof Mining District (Chicagof Mining District) | Mining District |
| Sitka | City Borough |
| Alaska | State |
| USA | Country |
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Latitude & Longitude (WGS84):
57° 43' 51'' North , 136° 16' 55'' West
Latitude & Longitude (decimal):
Type:
Köppen climate type:
The prospect is in West Chichagof-Yakobi Wilderness.
Location: The Congress prospect is at sea level about 0.4 mile northwest of the south tip of Hill Island. The prospect is near the southeast corner of sec. 2, T. 48 S., R. 56 E. It is location P-52 of Bittenbender and others (1999), location 24 of Cobb (1972, 1978), and MAS no. 0021140027 (U.S. Bureau of Land Management, 2002). The location is accurate within 0.2 mile.
Geology: Johnson and Karl (1985) map the rocks in the area of this prospect as hornfelsed, Cretaceous graywacke and argillite interbedded with sparse, lenticular beds of recrystallized basalt ('greenstone'). The formation is cut by many steeply-dipping, mainly northwest-striking faults. Cobb (1978), citing Overbeck (1919) and Reed and Coats (1941), reports that the prospect is a sulfide-bearing lens of schistose greenstone in graywacke. The sulfides are sparse chalcopyrite and pyrrhotite that occur in small quartz bodies and on foliation surfaces. The mineralized zone is 10 to 12 feet thick and was explored by a 25-foot tunnel. Bittenbender and others (1999), citing Still and Weir (1981), describe this prospect as a copper- and zinc-bearing volcanogenic massive sulfide deposit in greenstone. A 12-foot zone of silicified greenstone contained 0.58 percent copper and 0.086 percent zinc.
Workings: The deposit was explored by a 25-foot-long tunnel (Cobb, 1978).
Alteration: Greenstone is silicified.
Commodities (Major) - Cu; (Minor) - Zn
Development Status: Undetermined.
Deposit Model: Volcanogenic massive-sulfide deposit?
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
3 valid minerals.
Detailed Mineral List:
| ⓘ Chalcopyrite Formula: CuFeS2 |
| ⓘ Pyrrhotite Formula: Fe1-xS |
| ⓘ Quartz Formula: SiO2 |
Gallery:
List of minerals arranged by Strunz 10th Edition classification
| Group 2 - Sulphides and Sulfosalts | |||
|---|---|---|---|
| ⓘ | Chalcopyrite | 2.CB.10a | CuFeS2 |
| ⓘ | Pyrrhotite | 2.CC.10 | Fe1-xS |
| Group 4 - Oxides and Hydroxides | |||
| ⓘ | Quartz | 4.DA.05 | SiO2 |
List of minerals for each chemical element
| O | Oxygen | |
|---|---|---|
| O | ⓘ Quartz | SiO2 |
| Si | Silicon | |
| Si | ⓘ Quartz | SiO2 |
| S | Sulfur | |
| S | ⓘ Chalcopyrite | CuFeS2 |
| S | ⓘ Pyrrhotite | Fe1-xS |
| Fe | Iron | |
| Fe | ⓘ Chalcopyrite | CuFeS2 |
| Fe | ⓘ Pyrrhotite | Fe1-xS |
| Cu | Copper | |
| Cu | ⓘ Chalcopyrite | CuFeS2 |
Other Databases
| Link to USGS - Alaska: | SI075 |
|---|
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