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Nixon Fork - Crystal; Garnet Extension Mines, Yukon-Koyukuk Census Area, Alaska, USAi
| Regional Level Types | |
|---|---|
| Nixon Fork - Crystal; Garnet Extension Mines | Group of Mines |
| Yukon-Koyukuk Census Area | Census Area |
| Alaska | State |
| USA | Country |
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Latitude & Longitude (WGS84):
63° 14' 20'' North , 154° 46' 26'' West
Latitude & Longitude (decimal):
Type:
Group of Mines
Köppen climate type:
See Nixon Fork Mine (MD062).
Location: The Nixon Fork - Crystal and Garnet Extension mines are about 2,000 feet west of the Nixon Fork Mine (MD062), in Section 13, T. 26 S., R. 21 E., of the Kateel River Meridian. The reporter visited the site in 1995 and 1996.
Geology: The Nixon Fork - Crystal and Garnet Extension mines consist of locally gold-rich, contact metamorphic deposits in Paleozoic limestone, generally within a few feet of quartz monzonite contact. Although most ores are locally enriched by oxidation, the Crystal and Garnet Extension were distinguished from other ore bodies in the Nixon Fork Mine area by preservation of primary gold-bearing sulfide oe bodies. The deposits consist of chalcopyrite, pyrite, and bornite in a gangue of calcite, siderite, and zeolites. Hence the Crystal and Garnet extension deposits are considered unoxidized extensions of the Nixon Fork lode system (MD062). Age is probably Late Cretaceous, based on isotopic age (71.0 Ma) of associated monzonite (Moll and others, 1981). Assay data is summarized with the Nixon Fork mine (MD062).
Workings: The Nixon Fork Crystal and Garnet mines were discovered at the same time as the main Nixon Fork Deposit (MD062) in 1917 or 1918. The small but rich gold-skarn deposits were developed mainly by inclined shafts with branching levels.
Age: Age is probably Late Cretaceous, based on isotopic age (71.0 Ma) of associated monzonite (Moll and others, 1981).
Alteration: Extensive oxidation of primary sulfides.
Production: Production included with Nixon Fork Mine (MD062).
Commodities (Major) - Ag, Au; (Minor) - Bi, Cu, W
Development Status: Yes; small
Deposit Model: Copper-gold skarn (Cox and Singer, 1986; model no. 18b)
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
7 valid minerals.
Detailed Mineral List:
| ⓘ Arsenopyrite Formula: FeAsS |
| ⓘ Chalcopyrite Formula: CuFeS2 |
| ⓘ Epidote Formula: (CaCa)(AlAlFe3+)O[Si2O7][SiO4](OH) |
| ⓘ Magnetite Formula: Fe2+Fe3+2O4 |
| ⓘ Native Bismuth Formula: Bi |
| ⓘ Pyrite Formula: FeS2 |
| ⓘ Pyrite var. Gold-bearing Pyrite Formula: FeS2 |
| ⓘ Scheelite Formula: Ca(WO4) |
Gallery:
List of minerals arranged by Strunz 10th Edition classification
| Group 1 - Elements | |||
|---|---|---|---|
| ⓘ | Native Bismuth | 1.CA.05 | Bi |
| Group 2 - Sulphides and Sulfosalts | |||
| ⓘ | Chalcopyrite | 2.CB.10a | CuFeS2 |
| ⓘ | Pyrite var. Gold-bearing Pyrite | 2.EB.05a | FeS2 |
| ⓘ | 2.EB.05a | FeS2 | |
| ⓘ | Arsenopyrite | 2.EB.20 | FeAsS |
| Group 4 - Oxides and Hydroxides | |||
| ⓘ | Magnetite | 4.BB.05 | Fe2+Fe3+2O4 |
| Group 7 - Sulphates, Chromates, Molybdates and Tungstates | |||
| ⓘ | Scheelite | 7.GA.05 | Ca(WO4) |
| Group 9 - Silicates | |||
| ⓘ | Epidote | 9.BG.05a | (CaCa)(AlAlFe3+)O[Si2O7][SiO4](OH) |
List of minerals for each chemical element
| H | Hydrogen | |
|---|---|---|
| H | ⓘ Epidote | (CaCa)(AlAlFe3+)O[Si2O7][SiO4](OH) |
| O | Oxygen | |
| O | ⓘ Epidote | (CaCa)(AlAlFe3+)O[Si2O7][SiO4](OH) |
| O | ⓘ Magnetite | Fe2+Fe23+O4 |
| O | ⓘ Scheelite | Ca(WO4) |
| Al | Aluminium | |
| Al | ⓘ Epidote | (CaCa)(AlAlFe3+)O[Si2O7][SiO4](OH) |
| Si | Silicon | |
| Si | ⓘ Epidote | (CaCa)(AlAlFe3+)O[Si2O7][SiO4](OH) |
| S | Sulfur | |
| S | ⓘ Arsenopyrite | FeAsS |
| S | ⓘ Pyrite var. Gold-bearing Pyrite | FeS2 |
| S | ⓘ Chalcopyrite | CuFeS2 |
| S | ⓘ Pyrite | FeS2 |
| Ca | Calcium | |
| Ca | ⓘ Epidote | (CaCa)(AlAlFe3+)O[Si2O7][SiO4](OH) |
| Ca | ⓘ Scheelite | Ca(WO4) |
| Fe | Iron | |
| Fe | ⓘ Arsenopyrite | FeAsS |
| Fe | ⓘ Pyrite var. Gold-bearing Pyrite | FeS2 |
| Fe | ⓘ Chalcopyrite | CuFeS2 |
| Fe | ⓘ Epidote | (CaCa)(AlAlFe3+)O[Si2O7][SiO4](OH) |
| Fe | ⓘ Magnetite | Fe2+Fe23+O4 |
| Fe | ⓘ Pyrite | FeS2 |
| Cu | Copper | |
| Cu | ⓘ Chalcopyrite | CuFeS2 |
| As | Arsenic | |
| As | ⓘ Arsenopyrite | FeAsS |
| W | Tungsten | |
| W | ⓘ Scheelite | Ca(WO4) |
| Bi | Bismuth | |
| Bi | ⓘ Native Bismuth | Bi |
Other Databases
| Link to USGS - Alaska: | MD061 |
|---|
Other Regions, Features and Areas containing this locality
North AmericaContinent
North America PlateTectonic Plate
- Farewell-McGrath DomainDomain
- Farewell TerranePassive Margin
USA
- Alaska
- Yukon-Koyukuk Census Area
- McGrath Mining DistrictMining District
- Yukon-Koyukuk Census Area
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