Unnamed Occurrence (ARDF - MH244; south side of the West Fork Robertson River valley), Tok Mining District, Southeast Fairbanks Census Area, Alaska, USAi
This page is currently not sponsored. Click here to sponsor this page.
Latitude & Longitude (WGS84):
63° 18' 33'' North , 144° 44' 31'' West
Latitude & Longitude (decimal):
Köppen climate type:
Mindat Locality ID:
201285
Long-form identifier:
mindat:1:2:201285:1
GUID (UUID V4):
8379fc76-3693-4a24-87c3-b5a0d0d3aa30
Unpublished data cited is available for viewing by contacting Grayd Resources Inc. in Vancouver, B. C., Canada (www.grayd.com), or Northern Associates Inc. in Fairbanks, Alaska.
Location: This unnamed occurrence is about 1.8 miles southwest of the mouth of Rock Candy Creek. It is at an elevation of about 4,000 feet in the SE1/4 section 31, T. 18 S., R. 16 E., Fairbanks Meridian. The occurrence is on the moraine of the glacier at the head of the West Fork Robertson River near the junction with a smaller tributary glacier. The location is accurate.
Geology: Two types of massive sulfide mineralization were found on glacial moraine here during geological reconnaissance in 1975. These occurrences contain sparse base metal concentrations. Banded pyrrhotite with approximately 1 percent combined copper, lead, and zinc is in carbonate breccia with siliceous fragments. Pyrrhotite and calcite occur in bands that wrap around the breccia fragments. Farther up the glacier, banded pyrite and quartz-sericite schist with disseminated pyrite are abundant on the moraine on the ice. The rocks contains blueish-white quartz crystals and porphyroblasts as much as one-quarter inch in diameter; the protolith is probably a rhyolitic lapilli tuff. Along the southern side of the glacier, meta-andesite (?) with black chlorite and white tourmaline crystals developed in open spaces (R.A. Blakestad and others, unpublished Resource Associates of Alaska, Inc. report, 1976). This occurrence is in the Jarvis Creek Glacier subterrane of Devonian age (Nokleberg and others, 1992). This subterrane consists of a complex sequence of volcaniclastic metasedimentary rocks, predominantly of intermediate composition. The unit includes felsic and mafic metavolcanic units and metasedimentary rocks, including calcareous schist, dolomite, limestone, siltstone, quartzite, and black carbonaceous schist. The rock units are typically thin bedded, strike northwest, and dip moderately southwest. The schistosity and folds are generally parallel to the regional strike but with local exceptions (R.A. Blakestad and others, unpublished Resource Associates of Alaska, Inc. report, 1976). The metamorphosed volcanic and sedimentary rocks have been intruded by several gabbro and mafic sills and dikes and plutons of felsic to intermediate composition
Workings: This occurrence has only had limited surface sampling.
Age: Devonian or younger, on the basis of the age of the host rock, which is in the Jarvis Creek Glacier subterrane (Nokleberg and others, 1992).
Commodities (Major) - Cu, Pb, Zn
Development Status: None
Deposit Model: Kuroko massive sulfide (Cox and Singer, 1986; model 28a).
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:
ⓘ Calcite Formula: CaCO3 |
ⓘ Chalcopyrite Formula: CuFeS2 |
ⓘ Galena Formula: PbS |
ⓘ Pyrite Formula: FeS2 |
ⓘ Pyrrhotite Formula: Fe1-xS |
ⓘ Quartz Formula: SiO2 |
ⓘ Sphalerite Formula: ZnS |
Gallery:
List of minerals arranged by Strunz 10th Edition classification
Group 2 - Sulphides and Sulfosalts | |||
---|---|---|---|
ⓘ | Sphalerite | 2.CB.05a | ZnS |
ⓘ | Chalcopyrite | 2.CB.10a | CuFeS2 |
ⓘ | Pyrrhotite | 2.CC.10 | Fe1-xS |
ⓘ | Galena | 2.CD.10 | PbS |
ⓘ | Pyrite | 2.EB.05a | FeS2 |
Group 4 - Oxides and Hydroxides | |||
ⓘ | Quartz | 4.DA.05 | SiO2 |
Group 5 - Nitrates and Carbonates | |||
ⓘ | Calcite | 5.AB.05 | CaCO3 |
List of minerals for each chemical element
C | Carbon | |
---|---|---|
C | ⓘ Calcite | CaCO3 |
O | Oxygen | |
O | ⓘ Calcite | CaCO3 |
O | ⓘ Quartz | SiO2 |
Si | Silicon | |
Si | ⓘ Quartz | SiO2 |
S | Sulfur | |
S | ⓘ Chalcopyrite | CuFeS2 |
S | ⓘ Galena | PbS |
S | ⓘ Pyrite | FeS2 |
S | ⓘ Pyrrhotite | Fe1-xS |
S | ⓘ Sphalerite | ZnS |
Ca | Calcium | |
Ca | ⓘ Calcite | CaCO3 |
Fe | Iron | |
Fe | ⓘ Chalcopyrite | CuFeS2 |
Fe | ⓘ Pyrite | FeS2 |
Fe | ⓘ Pyrrhotite | Fe1-xS |
Cu | Copper | |
Cu | ⓘ Chalcopyrite | CuFeS2 |
Zn | Zinc | |
Zn | ⓘ Sphalerite | ZnS |
Pb | Lead | |
Pb | ⓘ Galena | PbS |
Other Databases
Link to USGS - Alaska: | MH244 |
---|
Other Regions, Features and Areas containing this locality
North America PlateTectonic Plate
- Windy-McKinley 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.