Portage Creek Occurrence, Bristol Bay Mining District, Lake and Peninsula Borough, Alaska, USAi
| Regional Level Types | |
|---|---|
| Portage Creek Occurrence | Occurrence |
| Bristol Bay Mining District | Mining District |
| Lake and Peninsula Borough | Borough |
| Alaska | State |
| USA | Country |
This page is currently not sponsored. Click here to sponsor this page.
Latitude & Longitude (WGS84):
60° 23' 5'' North , 154° 0' 36'' West
Latitude & Longitude (decimal):
Type:
Köppen climate type:
Nearest Settlements:
| Place | Population | Distance |
|---|---|---|
| Port Alsworth | 159 (2017) | 26.4km |
Site is in Lake Clark National Park and Preserve.
Location: Prospect is located about 3.6 km north of the mouth of Portage Creek. Locality 23 of Nelson and others (1985) and locality 15 of MacKevett and Holloway (1977). Sec. 5, T. 3 N., R. 27 W., of the Seward Meridian. Locality accurate within 800 m.
Geology: Only information is that lode claims (U.S. Bureau of Mines, 1973) are located along part of the Lake Clark fault. Near the claims, the fault separates metamorphic rocks of Paleozoic to Mesozoic age and Tertiary volcanic rocks. The claims appear to straddle the Lake Clark Fault and span both lithologies. According to Nelson and others (1983, unit MzPzm), metamorphosed mafic volcanic rocks are the most widespread rocks of this unit; they are aphanitic and were probably originally composed of plagioclase and pyroxene, and locally olivine and amphibole. These rocks have been altered, and they now consist mostly of chlorite, epidote, and fibrous amphibole. Other lithologies of this unit include: phyllite, schist, quartzite, marble, calc-silicate rocks, serpentinite, gabbro, and chert. Unit Tv is described by Nelson and others (1983) to include rhyolitic breccia, ash-flow tuff, flows, and intrusive rocks and subordinate mafic to intermediate flows. Potassium-argon ages for unit Tv range from 56.2 to 62.7 m.y. indicating a Tertiary age for these rocks (Eakins and others, 1978).
Workings: Unknown
Age: Unknown
Alteration: The metamorphic rocks consist mostly of chlorite, epidote, and fibrous amphibole (Nelson and others, 1983).
Production: No production
Reserves: No reserves
Commodities (Major) - Au; (Minor) - Ag
Development Status: None
Deposit Model: Unknown
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
1 valid mineral.
Detailed Mineral List:
| ⓘ Native Gold Formula: Au |
Gallery:
List of minerals arranged by Strunz 10th Edition classification
| Group 1 - Elements | |||
|---|---|---|---|
| ⓘ | Native Gold | 1.AA.05 | Au |
List of minerals for each chemical element
| Au | Gold | |
|---|---|---|
| Au | ⓘ Native Gold | Au |
Other Databases
| Link to USGS - Alaska: | LC028 |
|---|
Other Regions, Features and Areas containing this locality
North AmericaContinent
North America PlateTectonic Plate
- Peninsular-Tlikakila DomainDomain
- Peninsular TerraneVolcanic Arc
This page contains all mineral locality references listed on mindat.org. This does not claim to be a complete list. If you know of more minerals from this site, please register so you can add to our database. This locality information is for reference purposes only. You should never attempt to
visit any sites listed in mindat.org without first ensuring that you have the permission of the land and/or mineral rights holders
for access and that you are aware of all safety precautions necessary.
