Unnamed Occurrence (ARDF - NM113; Cobblestone River), Nome Mining District, Nome Census Area, Alaska, USAi
Regional Level Types | |
---|---|
Unnamed Occurrence (ARDF - NM113; Cobblestone River) | - not defined - |
Nome Mining District | Mining District |
Nome Census Area | Census Area |
Alaska | State |
USA | Country |
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Latitude & Longitude (WGS84):
64° 58' 50'' North , 165° 27' 50'' West
Latitude & Longitude (decimal):
KΓΆppen climate type:
Nearest Settlements:
Place | Population | Distance |
---|---|---|
Nome | 3,806 (2018) | 53.4km |
Mindat Locality ID:
201463
Long-form identifier:
mindat:1:2:201463:3
GUID (UUID V4):
7b8371ad-db14-48ff-83fb-7c87ff305788
Location: This occurrence is near an unnamed west-flowing tributary to the upper Cobblestone River. It is near the center of section 24, T. 6 S., R. 34 W., Kateel River Meridian. It is on a minor ridge at about 1,400 feet elevation. The occurrence is locality 38 of Hummel (1962 [MF 248]).
Geology: This is one of three graphite occurrences (this occurrence, NM023, and NM112) mapped by Hummel (1962 [MF 248]) in this part of the Kigluaik Mountains. At NM023, graphite with biotite is disseminated in schist and in segregations to 18 inches thick. It also occurs as sparse disseminations in pegmatite. Moffit (1913, p. 135-136) described a graphite-rich layer 8 inches thick between pegmatite and schist walls. This occurrence is probably also disseminations and segregations of graphite in schist. The graphite-bearing rocks are upper amphibolite facies schist and gneiss that are probably derived from Precambrian protoliths (Sainsbury, 1972; Bunker and others, 1979; Till and Dumoulin, 1994). They are thought to have undergone regional high-pressure metamorphism along with many other rocks of Seward Peninsula in the Late Jurassic or Early Cretaceous (Sainsbury, Coleman, and Kachadoorian, 1970; Forbes and others, 1984; Thurston, 1985; Patrick, 1988; Patrick and Evans, 1989; Armstrong and others, 1986; Hannula and McWilliams, 1995). Higher temperature metamorphism overprinted these rocks in conjunction with regional extension, crustal melting, and magmatism in the mid-Cretaceous (Throckmorton and Hummel, 1979; Till, 1983; Evans and Patrick, 1987; Leiberman, 1988; Patrick and Leiberman, 1988; Miller and Hudson, 1991; Miller and others, 1992; Dumitru and others, 1995; Hannula and others, 1995; Hudson and Arth, 1983; Hudson, 1994; Amato and others, 1994; Amato and Wright, 1997, 1998). Uplift of the higher temperature metamorphic rocks took place in the mid- to Late Cretaceous and in the Eocene (Calvert, 1992; Dumitru and others, 1995).
Age: Mid-Cretaceous, the age of high-grade metamorphism.
Commodities (Major) - Graphite
Development Status: None
Deposit Model: Graphite disseminations and segregations in amphibolite facies metamorphic rocks
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:
β 'Biotite' Formula: K(Fe2+/Mg)2(Al/Fe3+/Mg/Ti)([Si/Al/Fe]2Si2O10)(OH/F)2 |
β 'Feldspar Group' |
β 'Garnet Group' Formula: X3Z2(SiO4)3 |
β Graphite Formula: C |
β Quartz Formula: SiO2 |
β Sillimanite Formula: Al2(SiO4)O |
Gallery:
List of minerals arranged by Strunz 10th Edition classification
Group 1 - Elements | |||
---|---|---|---|
β | Graphite | 1.CB.05a | C |
Group 4 - Oxides and Hydroxides | |||
β | Quartz | 4.DA.05 | SiO2 |
Group 9 - Silicates | |||
β | Sillimanite | 9.AF.05 | Al2(SiO4)O |
Unclassified | |||
β | 'Biotite' | - | K(Fe2+/Mg)2(Al/Fe3+/Mg/Ti)([Si/Al/Fe]2Si2O10)(OH/F)2 |
β | 'Feldspar Group' | - | |
β | 'Garnet Group' | - | X3Z2(SiO4)3 |
List of minerals for each chemical element
H | Hydrogen | |
---|---|---|
H | β Biotite | K(Fe2+/Mg)2(Al/Fe3+/Mg/Ti)([Si/Al/Fe]2Si2O10)(OH/F)2 |
C | Carbon | |
C | β Graphite | C |
O | Oxygen | |
O | β Biotite | K(Fe2+/Mg)2(Al/Fe3+/Mg/Ti)([Si/Al/Fe]2Si2O10)(OH/F)2 |
O | β Quartz | SiO2 |
O | β Sillimanite | Al2(SiO4)O |
O | β Garnet Group | X3Z2(SiO4)3 |
F | Fluorine | |
F | β Biotite | K(Fe2+/Mg)2(Al/Fe3+/Mg/Ti)([Si/Al/Fe]2Si2O10)(OH/F)2 |
Mg | Magnesium | |
Mg | β Biotite | K(Fe2+/Mg)2(Al/Fe3+/Mg/Ti)([Si/Al/Fe]2Si2O10)(OH/F)2 |
Al | Aluminium | |
Al | β Biotite | K(Fe2+/Mg)2(Al/Fe3+/Mg/Ti)([Si/Al/Fe]2Si2O10)(OH/F)2 |
Al | β Sillimanite | Al2(SiO4)O |
Si | Silicon | |
Si | β Biotite | K(Fe2+/Mg)2(Al/Fe3+/Mg/Ti)([Si/Al/Fe]2Si2O10)(OH/F)2 |
Si | β Quartz | SiO2 |
Si | β Sillimanite | Al2(SiO4)O |
Si | β Garnet Group | X3Z2(SiO4)3 |
K | Potassium | |
K | β Biotite | K(Fe2+/Mg)2(Al/Fe3+/Mg/Ti)([Si/Al/Fe]2Si2O10)(OH/F)2 |
Ti | Titanium | |
Ti | β Biotite | K(Fe2+/Mg)2(Al/Fe3+/Mg/Ti)([Si/Al/Fe]2Si2O10)(OH/F)2 |
Fe | Iron | |
Fe | β Biotite | K(Fe2+/Mg)2(Al/Fe3+/Mg/Ti)([Si/Al/Fe]2Si2O10)(OH/F)2 |
Other Databases
Link to USGS - Alaska: | NM113 |
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Other Regions, Features and Areas containing this locality
North America PlateTectonic Plate
- Brooks-Seward DomainDomain
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