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Portage Prospect, Admiralty Mining District, Hoonah-Angoon Census Area, Alaska, USAi
| Regional Level Types | |
|---|---|
| Portage Prospect | Prospect |
| Admiralty Mining District | Mining District |
| Hoonah-Angoon Census Area | Census Area |
| Alaska | State |
| USA | Country |
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Latitude & Longitude (WGS84):
58° 17' 14'' North , 134° 51' 43'' West
Latitude & Longitude (decimal):
Type:
Köppen climate type:
Nearest Settlements:
| Place | Population | Distance |
|---|---|---|
| Juneau | 32,756 (2017) | 25.9km |
Location: The Portage prospect is at an elevation of approximately 900 feet at the head of Bear Creek, on the northeast side of Green Mountain. It is 2 miles north-northeast of Funter Bay in the SE1/4NE1/4 section 25, T. 41 S., R. 65 E. of the Copper River Meridian. The location is accurate within 1/4 mile.
Geology: The Portage prospect consists of lenticular quartz masses in slate that are sub-parallel to the cleavage (Cobb, 1978 [OFR 78-374]). The quartz contains disseminated pyrite, chalcopyrite, and minor galena. The prospect contained low gold values by 1900 standards (Cobb, 1978 [OFR 78-374]). Nearby, chlorite-mica schist is cut by quartz-calcite veinlets contain small masses of pyrite and chalcopyrite across a width of 30 to 40 feet (Wells and others, 1986). The deposit was discovered prior to 1906 and was explored by a small shaft, a tunnel that failed to reach the ore zone, open cuts, and trenches (Wright, 1907) The deposit in the mica schist resembles the one at the Mammoth prospect (JU248) (Cobb, 1978 [OFR 78-374]). The rocks in the area are mainly Ordovician and Devonian to Triassic clastic strata, mafic-intermediate volcanic rocks, and subordinate limestone. The bedded rocks are intruded and locally metamorphosed by Cretaceous granodiorite (Gehrels and Berg, 1994).
Workings: Surface sampling, shallow shaft, tunnel, open cuts, and trenches.
Commodities (Major) - Au, Cu, Pb
Development Status: No
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:
| ⓘ Calcite Formula: CaCO3 |
| ⓘ Chalcopyrite Formula: CuFeS2 |
| ⓘ Galena Formula: PbS |
| ⓘ Pyrite Formula: FeS2 |
| ⓘ Quartz Formula: SiO2 |
Gallery:
List of minerals arranged by Strunz 10th Edition classification
| Group 2 - Sulphides and Sulfosalts | |||
|---|---|---|---|
| ⓘ | Chalcopyrite | 2.CB.10a | CuFeS2 |
| ⓘ | Galena | 2.CD.10 | PbS |
| ⓘ | Pyrite | 2.EB.05a | FeS2 |
| Group 4 - Oxides and Hydroxides | |||
| ⓘ | Quartz | 4.DA.05 | SiO2 |
| Group 5 - Nitrates and Carbonates | |||
| ⓘ | Calcite | 5.AB.05 | CaCO3 |
List of minerals for each chemical element
| C | Carbon | |
|---|---|---|
| C | ⓘ Calcite | CaCO3 |
| O | Oxygen | |
| O | ⓘ Calcite | CaCO3 |
| O | ⓘ Quartz | SiO2 |
| Si | Silicon | |
| Si | ⓘ Quartz | SiO2 |
| S | Sulfur | |
| S | ⓘ Chalcopyrite | CuFeS2 |
| S | ⓘ Galena | PbS |
| S | ⓘ Pyrite | FeS2 |
| Ca | Calcium | |
| Ca | ⓘ Calcite | CaCO3 |
| Fe | Iron | |
| Fe | ⓘ Chalcopyrite | CuFeS2 |
| Fe | ⓘ Pyrite | FeS2 |
| Cu | Copper | |
| Cu | ⓘ Chalcopyrite | CuFeS2 |
| Pb | Lead | |
| Pb | ⓘ Galena | PbS |
Other Databases
| Link to USGS - Alaska: | JU136 |
|---|
Other Regions, Features and Areas containing this locality
North AmericaContinent
North America PlateTectonic Plate
- Alexander DomainDomain
- Alexander TerraneVolcanic Arc
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