Unnamed Occurrence (ARDF - MG083; near Post River), McGrath Mining District, Bethel Census Area, Alaska, USAi
| Regional Level Types | |
|---|---|
| Unnamed Occurrence (ARDF - MG083; near Post 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):
62° 3' 46'' North , 153° 26' 45'' West
Latitude & Longitude (decimal):
Köppen climate type:
Mindat Locality ID:
201168
Long-form identifier:
mindat:1:2:201168:7
GUID (UUID V4):
a19d9747-d51a-415c-bd5e-a468ab9411fd
Location: This unnamed occurrence is located in a northeast-facing slope near a saddle between two northeast-flowing tributaries of Post River. It is at an elevation of 5,180 feet (1,579 m) in the SW1/4 sec. 23, T. 23 N., R. 23 W., of the Seward Meridian. The occurrence corresponds to map number 33 in Bundtzen, Harris, and Gilbert (1997) The reporter investigated the site in 1988; at station nos. 88BT150-151.
Geology: This unnamed occurrence consists of significant amounts of cross-cutting quartz-sulfide stringers and stockwork in dacite-andesite flows and tuffs of the Eocene Terra Cotta Volcanic Field (Bundtzen, Harris, and Gilbert, 1997). Individual veins range from 2 to 10 centimeters thick and contain 3 to 8 percent pyrite and a bladed Sb mineral - probably stibnite. An elongate, SE to NW-trending, 45 meter wide by 110 meter long area of hydrothermal alteration contains intense silicification of andesite and strong ferricrete gossan. About 10 percent of the area is a sulfide gossan. A northeast- trending fault breccia cuts off the sulfidized zone on the southeast; the northeast limit of the mineralized area is obscured by talus and a snow field (present in 1988). Two grab samples of sulfide-quartz stockwork contain up to 4,200 ppm arsenic, 360 ppb gold, 150 ppm antimony, and 2,100 ppm zinc (Bundtzen, Harris, and Gilbert, 1997).
Workings: The reporter found the mineralization during geologic mapping for the Alaska Division of Geological and Geophysical Surveys in 1988 (Bundtzen, Harris, and Gilbert, 1997). Two grab samples of sulfide-quartz stockwork contain up to 4,200 ppm arsenic, 360 ppb gold, 150 ppm antimony, and 2,100 ppm zinc.
Age: Unknown; hosted in Eocene Terra Cotta Volcanic Field (Solie and others, 1991).
Alteration: Strong silicification and ferricrete gossan.
Reserves: None.
Commodities (Major) - As, Au, Zn; (Minor) - Sb
Development Status: No
Deposit Model: Creede epithermal vein (?) (Cox and Singer, 1986; model 25b).
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.
Gallery:
List of minerals arranged by Strunz 10th Edition classification
| Group 2 - Sulphides and Sulfosalts | |||
|---|---|---|---|
| ⓘ | Pyrite | 2.EB.05a | FeS2 |
| 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 | ⓘ Pyrite | FeS2 |
| Fe | Iron | |
| Fe | ⓘ Pyrite | FeS2 |
Other Databases
| Link to USGS - Alaska: | MG083 |
|---|
Other Regions, Features and Areas containing this locality
North America PlateTectonic Plate
- Farewell-McGrath DomainDomain
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.
References
