Hetta Mountain Prospects, Hetta Mountain, Prince of Wales Island, Ketchikan Mining District, Prince of Wales-Hyder Census Area, Alaska, USAi
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Latitude & Longitude (WGS84):
55° 11' 50'' North , 132° 34' 4'' West
Latitude & Longitude (decimal):
Type:
Group of Prospects
KΓΆppen climate type:
Nearest Settlements:
Place | Population | Distance |
---|---|---|
Hydaburg | 391 (2017) | 16.5km |
Hollis | 112 (2011) | 40.2km |
Thorne Bay | 483 (2017) | 54.6km |
Mindat Locality ID:
197959
Long-form identifier:
mindat:1:2:197959:9
GUID (UUID V4):
ba027776-940d-4343-be04-9421e147af6a
The 14 patented claims at this propect are surrounded by land whose surface and subsurface rights have been conveyed to, or are under application for transfer to, the Sealaska Corporation.
Location: These prospects are at an elevation of about 2,800 feet near the summit of Hetta Mountain; they are in the NW1/4 section 14, T. 77 S., R. 85 E.
Geology: The Hetta Mountain prospects are on 14 patented claims. The workings, all of which date from before WW I, consist of three short adits and several trenches (Wright and Wright,1908; Wright, 1915; Herreid and others, 1978; Maas and others, 1991, 1995). The rocks in the vicinity consist of a faulted-bounded block of Late Proterozoic or Cambrian marble of the Wales Group that is surrounded by Cretaceous, albite-epidote hornfels and garnet-bearing hornblende hornfels. The metamorphic rocks are cut by several granitic dikes, and the marble is locally altered to skarn. In one adit, a shear zone about 80 feet thick in marble contains diopside-garnet skarn with veinlets and blebs of chalcopyrite. In another adit, three short, en echelon pods of massive pyrite, pyrrhotite, and chalcopyrite replace marble along a porphyritic diorite dike (Herreid and others, 1978). A grab sample of rich ore contained 2.2 percent copper, 0.74 percent zinc, 12.3 ounces of silver per ton, 0.10 ounce of gold per ton, 600 parts per million (ppm) molybdenum, 750 ppm cobalt, and 22 ppm lead. Maas and others (1991) collected 15 samples from the prospects. Several had insignificant metal values, but the best contained 4.17 percent copper, 43.8 ppm silver, and 0.572 ppm gold. Wright and Wright (1908) show several additional prospects along the trail from the head of Copper Harbor to Hetta Mountain. At one, at an elevation of about 1,380 feet, a small mass of chalcopyrite is exposed in a 30-foot tunnel.
Workings: The Hetta Mountain prospects are on 14 patented claims. The workings, all of which date from before WW I, consist of three short adits and several trenches.
Age: Probably Cretaceous.
Alteration: Locally, skarn is developed in marble.
Commodities (Major) - Ag, Au, Cu, Fe, Zn; (Minor) - Co, Mo, Pb
Development Status: None
Deposit Model: Copper skarn (Singer and Cox, 1987; model 18b).
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
5 valid minerals.
Detailed Mineral List:
β Chalcopyrite Formula: CuFeS2 |
β Epidote Formula: (CaCa)(AlAlFe3+)O[Si2O7][SiO4](OH) |
β 'Garnet Group' Formula: X3Z2(SiO4)3 |
β Pyrite Formula: FeS2 |
β Pyrrhotite Formula: Fe1-xS |
β Quartz Formula: SiO2 |
Gallery:
List of minerals arranged by Strunz 10th Edition classification
Group 2 - Sulphides and Sulfosalts | |||
---|---|---|---|
β | Chalcopyrite | 2.CB.10a | CuFeS2 |
β | Pyrrhotite | 2.CC.10 | Fe1-xS |
β | Pyrite | 2.EB.05a | FeS2 |
Group 4 - Oxides and Hydroxides | |||
β | Quartz | 4.DA.05 | SiO2 |
Group 9 - Silicates | |||
β | Epidote | 9.BG.05a | (CaCa)(AlAlFe3+)O[Si2O7][SiO4](OH) |
Unclassified | |||
β | 'Garnet Group' | - | X3Z2(SiO4)3 |
List of minerals for each chemical element
H | Hydrogen | |
---|---|---|
H | β Epidote | (CaCa)(AlAlFe3+)O[Si2O7][SiO4](OH) |
O | Oxygen | |
O | β Epidote | (CaCa)(AlAlFe3+)O[Si2O7][SiO4](OH) |
O | β Quartz | SiO2 |
O | β Garnet Group | X3Z2(SiO4)3 |
Al | Aluminium | |
Al | β Epidote | (CaCa)(AlAlFe3+)O[Si2O7][SiO4](OH) |
Si | Silicon | |
Si | β Epidote | (CaCa)(AlAlFe3+)O[Si2O7][SiO4](OH) |
Si | β Quartz | SiO2 |
Si | β Garnet Group | X3Z2(SiO4)3 |
S | Sulfur | |
S | β Chalcopyrite | CuFeS2 |
S | β Pyrite | FeS2 |
S | β Pyrrhotite | Fe1-xS |
Ca | Calcium | |
Ca | β Epidote | (CaCa)(AlAlFe3+)O[Si2O7][SiO4](OH) |
Fe | Iron | |
Fe | β Chalcopyrite | CuFeS2 |
Fe | β Epidote | (CaCa)(AlAlFe3+)O[Si2O7][SiO4](OH) |
Fe | β Pyrite | FeS2 |
Fe | β Pyrrhotite | Fe1-xS |
Cu | Copper | |
Cu | β Chalcopyrite | CuFeS2 |
Other Databases
Link to USGS - Alaska: | CR157 |
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Other Regions, Features and Areas containing this locality
North America PlateTectonic Plate
- Alexander DomainDomain
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