Unnamed Occurrence (ARDF - TL008), Yentna Mining District, Matanuska-Susitna Borough, Alaska, USAi
| Regional Level Types | |
|---|---|
| Unnamed Occurrence (ARDF - TL008) | - not defined - |
| Yentna Mining District | Mining District |
| Matanuska-Susitna Borough | Borough |
| Alaska | State |
| USA | Country |
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Latitude & Longitude (WGS84):
62° 44' 42'' North , 151° 49' 33'' West
Latitude & Longitude (decimal):
Köppen climate type:
Mindat Locality ID:
202670
Long-form identifier:
mindat:1:2:202670:4
GUID (UUID V4):
85a81500-6264-4c63-97eb-b8f3a4b41e5e
This prospect is located within Denali National Park and Preserve.
Location: Reed and others (1978, locality 24 and 25) locate this occurrence in the southwest quarter of Section 25, T. 31 N., R. 14 W., of the Seward Meridian on a nunatak within the Dall Glacier in Denali National Park and Preserve.
Geology: Reed and others (1978) describe this coincident mineral occurrence of a quartz-molybdenite vein cutting Paleozoic and (or) Mesozoic (Reed and Nelson, 1980) or Late Cretaceous/early Tertiary (?) (Foley and others, 1997) chromite-bearing dunite. The quartz-molybdenite vein is 20 to 50 centimeters thick, with as much as 20 volume percent molybdenite as foliated tabular crystals up to 5 centimeters in diameter. It is probably genetically related to the middle Tertiary (38 m.y.) granodiorite of Mt. Foraker (Reed and Nelson, 1980) and may indicate porphyry molybdenum/copper potential (Reed and others, 1978). The dunite is part of the Dall trend described in TL002, 003, TL009 - 012, and TL055.
Workings: Reconnaissance mapping, stream silt and rock sampling are all that have been done here. Chromium content of 0.7 to 1% from typical dunite is given in Reed and others (1978). The average of 3 microprobe analyses of one sample was 58.4% Cr2O3, 21.1% FeO, 8.9% MgO, and 9.7% Al2O3.
Age: Mesozoic and (or) Paleozoic (Reed and Nelson, 1980) or Late Cretaceous/early Tertiary (?) (Foley and others, 1997) chromite-bearing dunite. Tertiary; vein hosted quartz-molybdenite presumed to be related to the middle Tertiary (38 m.y.) granodiorite (Reed and others, 1978).
Commodities (Major) - Cr, Mo
Development Status: None
Deposit Model: Podiform chromite (Cox and Singer, 1986; model 8a); vein is possibly related to
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
3 valid minerals.
Detailed Mineral List:
| ⓘ Chromite Formula: Fe2+Cr3+2O4 |
| ⓘ Molybdenite Formula: MoS2 |
| ⓘ Quartz Formula: SiO2 |
Gallery:
List of minerals arranged by Strunz 10th Edition classification
| Group 2 - Sulphides and Sulfosalts | |||
|---|---|---|---|
| ⓘ | Molybdenite | 2.EA.30 | MoS2 |
| Group 4 - Oxides and Hydroxides | |||
| ⓘ | Chromite | 4.BB.05 | Fe2+Cr3+2O4 |
| ⓘ | Quartz | 4.DA.05 | SiO2 |
List of minerals for each chemical element
| O | Oxygen | |
|---|---|---|
| O | ⓘ Chromite | Fe2+Cr23+O4 |
| O | ⓘ Quartz | SiO2 |
| Si | Silicon | |
| Si | ⓘ Quartz | SiO2 |
| S | Sulfur | |
| S | ⓘ Molybdenite | MoS2 |
| Cr | Chromium | |
| Cr | ⓘ Chromite | Fe2+Cr23+O4 |
| Fe | Iron | |
| Fe | ⓘ Chromite | Fe2+Cr23+O4 |
| Mo | Molybdenum | |
| Mo | ⓘ Molybdenite | MoS2 |
Other Databases
| Link to USGS - Alaska: | TL008 |
|---|
Other Regions, Features and Areas containing this locality
North America PlateTectonic Plate
- Farewell-McGrath DomainDomain
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References
