Sweeny; Comet City Prospect, Juneau Mining District, Juneau, Alaska, USAi
| Regional Level Types | |
|---|---|
| Sweeny; Comet City Prospect | Prospect |
| Juneau Mining District | Mining District |
| Juneau | City Borough |
| Alaska | State |
| USA | Country |
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Latitude & Longitude (WGS84):
58° 51' 14'' North , 135° 7' 40'' West
Latitude & Longitude (decimal):
Type:
Köppen climate type:
Location: The Sweeny prospect is at an elevation of about 350 feet, about 1 mile east of Pt. Sherman on Lynn Canal and 3 miles southwest of Lions Head Mountain in the Kakuhan Range. It is in the Sherman Creek drainage in the NE1/4 section 7, T. 35 S., R. 62 E. of the Copper River Meridian. The location is accurate.
Geology: The Sweeny prospect, originally called the Comet City mine, was developed in 1904 by T.H. Jarmey, who completed 2 adits,estimated to be 20 feet and 100 feet long, by 1905. The deposit is in black phyllite and consists of several thin concordant, discontinuous quartz veins that carry minor amounts of pyrrhotite. U.S. Bureau of Mines samples contained elevated lead values but no gold (Redman and others, 1989). The Sweeny prospect is in the Berners Bay district at the north end of the Juneau Gold Belt. The district is characterized by a series of structurally-controlled, mesothermal, gold-bearing quartz veins. Most of the veins are in Early Cretaceous (105 Ma) Jualin Diorite, which intrudes Mesozoic (Upper Triassic) metabasalt (Miller and others, 1995). The age of mineralization in the Berners Bay district is about 55 Ma, the same as the other mesothermal gold vein deposits in the Juneau Gold Belt (Goldfarb and others, 1997).
Workings: The Sweeny prospect, originally called the Comet City mine, was developed in 1904 by T.H. Jarmey, who completed 2 adits, estimated to be 20 feet and 100 feet long, by 1905. This prospect is currently (2001) under control of Coeur Alaska.
Age: The age of mineralization in the Berners Bay district is about 55 Ma, the same as the other mesothermal gold-quartz-vein deposits in the Juneau Gold Belt (Goldfarb and others, 1997).
Commodities (Major) - Au; (Minor) - Pb
Development Status: None
Deposit Model: Low-sulfide Au-quartz vein (Cox and Singer, 1986; model 36a)
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
2 valid minerals.
Detailed Mineral List:
| ⓘ Pyrrhotite Formula: Fe1-xS |
| ⓘ Quartz Formula: SiO2 |
Gallery:
List of minerals arranged by Strunz 10th Edition classification
| Group 2 - Sulphides and Sulfosalts | |||
|---|---|---|---|
| ⓘ | 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 | ⓘ Pyrrhotite | Fe1-xS |
| Fe | Iron | |
| Fe | ⓘ Pyrrhotite | Fe1-xS |
Other Databases
| Link to USGS - Alaska: | JU038 |
|---|
Other Regions, Features and Areas containing this locality
North AmericaContinent
- Coast MountainsMountain Range
North America PlateTectonic Plate
- Taku DomainDomain
- Yukon-TananaVolcanic Arc
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