Unnamed Occurrences (ARDF - LH023; head of Kuskokwim River), McGrath Mining District, Bethel Census Area, Alaska, USAi
| Regional Level Types | |
|---|---|
| Unnamed Occurrences (ARDF - LH023; head of Kuskokwim River) | - not defined - |
| McGrath Mining District | Mining District |
| Bethel Census Area | Census Area |
| Alaska | State |
| USA | Country |
This page is currently not sponsored. Click here to sponsor this page.
Latitude & Longitude (WGS84):
61° 29' 23'' North , 153° 28' 58'' West
Latitude & Longitude (decimal):
Köppen climate type:
Location: This occurrence is in the headwaters of the South Fork Kuskokwim River. It is at an elevation of 4,000 feet along the south side of the river valley and 5.3 miles northeast of Snowcap Mountain. The map site is in the SE 1/4 section 12, T 16 N, R 24 W, of the Seward Meridian. This is locality 9 of Cobb (1972 [MF 412]; 1976 [OF 76-485]). The location is probably accurate to within one mile. Included with this location is a reported gold occurrence (Resource Associates of Alaska, 1976, p. 86) that is about 1 mile to the east, near peak 6425.
Geology: Reed and Elliott (1970) reported that quartz float at this locality includes cobbles containing (1) as much as 40 percent disseminated pyrrhotite and minor chalcopyrite, (2) less than 2 percent molybdenite, and (3) 1- to 3-mm- wide veinlets with less than 10 percent sphalerite and pyrite. Samples contained as much as 12 ppm gold (Reed and Elliott, 1970; Gamble and others, 1989). Quartz veins 1 mile to the east, near peak 6425, are as much as 6 inches wide and contain arsenopyrite, pyrite, chalcopyrite, pyrrhotite, and as much as 2.3 ppm gold (Resource Associates of Alaska, 1976). These occurrences are near the contact of Tertiary diorite and quartz monzonite stocks with Cretaceous sedimentary rocks.
Workings: Reconnaissance sampling has been completed in this area (Reed and Elliott, 1970).
Age: Tertiary. Quartz veins crosscut Tertiary intrusive rocks or nearby, thermally metamorphosed sedimentary rocks.
Alteration: Silicification.
Commodities (Major) - Au, Cu, Mo, Zn
Development Status: None
Deposit Model: Polymetallic veins (Cox and Singer, 1986, model 22c)
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
9 valid minerals.
Detailed Mineral List:
| ⓘ Ankerite Formula: Ca(Fe2+,Mg)(CO3)2 |
| ⓘ Arsenopyrite Formula: FeAsS |
| ⓘ Calcite Formula: CaCO3 |
| ⓘ Chalcopyrite Formula: CuFeS2 |
| ⓘ Molybdenite Formula: MoS2 |
| ⓘ Pyrite Formula: FeS2 |
| ⓘ Pyrrhotite Formula: Fe1-xS |
| ⓘ Quartz Formula: SiO2 |
| ⓘ Sphalerite Formula: ZnS |
Gallery:
List of minerals arranged by Strunz 10th Edition classification
| Group 2 - Sulphides and Sulfosalts | |||
|---|---|---|---|
| ⓘ | Sphalerite | 2.CB.05a | ZnS |
| ⓘ | Chalcopyrite | 2.CB.10a | CuFeS2 |
| ⓘ | Pyrrhotite | 2.CC.10 | Fe1-xS |
| ⓘ | Molybdenite | 2.EA.30 | MoS2 |
| ⓘ | Pyrite | 2.EB.05a | FeS2 |
| ⓘ | Arsenopyrite | 2.EB.20 | FeAsS |
| Group 4 - Oxides and Hydroxides | |||
| ⓘ | Quartz | 4.DA.05 | SiO2 |
| Group 5 - Nitrates and Carbonates | |||
| ⓘ | Calcite | 5.AB.05 | CaCO3 |
| ⓘ | Ankerite | 5.AB.10 | Ca(Fe2+,Mg)(CO3)2 |
List of minerals for each chemical element
| C | Carbon | |
|---|---|---|
| C | ⓘ Ankerite | Ca(Fe2+,Mg)(CO3)2 |
| C | ⓘ Calcite | CaCO3 |
| O | Oxygen | |
| O | ⓘ Ankerite | Ca(Fe2+,Mg)(CO3)2 |
| O | ⓘ Calcite | CaCO3 |
| O | ⓘ Quartz | SiO2 |
| Mg | Magnesium | |
| Mg | ⓘ Ankerite | Ca(Fe2+,Mg)(CO3)2 |
| Si | Silicon | |
| Si | ⓘ Quartz | SiO2 |
| S | Sulfur | |
| S | ⓘ Arsenopyrite | FeAsS |
| S | ⓘ Chalcopyrite | CuFeS2 |
| S | ⓘ Molybdenite | MoS2 |
| S | ⓘ Pyrite | FeS2 |
| S | ⓘ Pyrrhotite | Fe1-xS |
| S | ⓘ Sphalerite | ZnS |
| Ca | Calcium | |
| Ca | ⓘ Ankerite | Ca(Fe2+,Mg)(CO3)2 |
| Ca | ⓘ Calcite | CaCO3 |
| Fe | Iron | |
| Fe | ⓘ Ankerite | Ca(Fe2+,Mg)(CO3)2 |
| Fe | ⓘ Arsenopyrite | FeAsS |
| Fe | ⓘ Chalcopyrite | CuFeS2 |
| Fe | ⓘ Pyrite | FeS2 |
| Fe | ⓘ Pyrrhotite | Fe1-xS |
| Cu | Copper | |
| Cu | ⓘ Chalcopyrite | CuFeS2 |
| Zn | Zinc | |
| Zn | ⓘ Sphalerite | ZnS |
| As | Arsenic | |
| As | ⓘ Arsenopyrite | FeAsS |
| Mo | Molybdenum | |
| Mo | ⓘ Molybdenite | MoS2 |
Other Databases
| Link to USGS - Alaska: | LH023 |
|---|
Other Regions, Features and Areas containing this locality
North AmericaContinent
North America PlateTectonic Plate
- Farewell buried DomainDomain
- Farewell TerranePassive Margin
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.
