Unnamed Occurrence (ARDF - MH109; east of lower Eureka Glacier), Delta River Mining District, Southeast Fairbanks Census Area, Alaska, USAi
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Latitude & Longitude (WGS84):
63° 19' 7'' North , 146° 15' 28'' West
Latitude & Longitude (decimal):
Köppen climate type:
Mindat Locality ID:
201215
Long-form identifier:
mindat:1:2:201215:8
GUID (UUID V4):
a8bea57e-690a-4a5f-860f-b04cd99f3372
Location: This occurrence is at an elevation of 4,700 feet about 2.25 miles east of lower Eureka Glacier. It is in the eastern headwaters of locally named Landslide Creek, a south-flowing tributary of Eureka Creek, and about one-half mile south-southwest of the center of section 29, T. 18 S., R. 8 E., Fairbanks Meridian. The occurrence corresponds to locality 41 in table 2 of Nokleberg and others (1991) and to locality 6 in figure 3 of Rose (1966 [ADMM GR 20]).
Geology: This occurrence is in an Upper Triassic sill-like body of serpentinized dunite that can be traced continuously for more than 5 miles (Rose, 1966 [ADMM GR 20, figure 3]). The body is the main unit of the informally named Eureka ultramafic complex that occupies strands of the Broxson Gulch thrust fault (Nokleberg and others, 1991; W.T. Ellis, unpublished data, 1996). The occurrence consists of veins and discontinuous lenses of opal, calcite, chrysotile, magnetite, chromite, and an unidentified green glassy mineral (Rose, 1966 [ADMM GR 20, p. 20]). Chromite is also disseminated in the dunite. No assay data are available.
Workings: The occurrence is on active MAN Resources claims.
Age: Late Triassic, the age of the host rock.
Alteration: All of the ultramafic rock units are moderately to strongly serpentinized.
Commodities (Major) - Cr
Development Status: None
Deposit Model: Disseminated and vein-like masses of chromite in a mafic-ultramafic sill-like bo
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 |
ⓘ Chromite Formula: Fe2+Cr3+2O4 |
ⓘ Chrysotile Formula: Mg3(Si2O5)(OH)4 |
ⓘ Magnetite Formula: Fe2+Fe3+2O4 |
ⓘ Opal Formula: SiO2 · nH2O |
ⓘ 'Serpentine Subgroup' Formula: D3[Si2O5](OH)4 |
Gallery:
List of minerals arranged by Strunz 10th Edition classification
Group 4 - Oxides and Hydroxides | |||
---|---|---|---|
ⓘ | Chromite | 4.BB.05 | Fe2+Cr3+2O4 |
ⓘ | Magnetite | 4.BB.05 | Fe2+Fe3+2O4 |
ⓘ | Opal | 4.DA.10 | SiO2 · nH2O |
Group 5 - Nitrates and Carbonates | |||
ⓘ | Calcite | 5.AB.05 | CaCO3 |
Group 9 - Silicates | |||
ⓘ | Chrysotile | 9.. | Mg3(Si2O5)(OH)4 |
Unclassified | |||
ⓘ | 'Serpentine Subgroup' | - | D3[Si2O5](OH)4 |
List of minerals for each chemical element
H | Hydrogen | |
---|---|---|
H | ⓘ Chrysotile | Mg3(Si2O5)(OH)4 |
H | ⓘ Opal | SiO2 · nH2O |
H | ⓘ Serpentine Subgroup | D3[Si2O5](OH)4 |
C | Carbon | |
C | ⓘ Calcite | CaCO3 |
O | Oxygen | |
O | ⓘ Calcite | CaCO3 |
O | ⓘ Chrysotile | Mg3(Si2O5)(OH)4 |
O | ⓘ Chromite | Fe2+Cr23+O4 |
O | ⓘ Magnetite | Fe2+Fe23+O4 |
O | ⓘ Opal | SiO2 · nH2O |
O | ⓘ Serpentine Subgroup | D3[Si2O5](OH)4 |
Mg | Magnesium | |
Mg | ⓘ Chrysotile | Mg3(Si2O5)(OH)4 |
Si | Silicon | |
Si | ⓘ Chrysotile | Mg3(Si2O5)(OH)4 |
Si | ⓘ Opal | SiO2 · nH2O |
Si | ⓘ Serpentine Subgroup | D3[Si2O5](OH)4 |
Ca | Calcium | |
Ca | ⓘ Calcite | CaCO3 |
Cr | Chromium | |
Cr | ⓘ Chromite | Fe2+Cr23+O4 |
Fe | Iron | |
Fe | ⓘ Chromite | Fe2+Cr23+O4 |
Fe | ⓘ Magnetite | Fe2+Fe23+O4 |
Other Databases
Link to USGS - Alaska: | MH109 |
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Other Regions, Features and Areas containing this locality
North America PlateTectonic Plate
- Wrangellia DomainDomain
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