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Tarn Prospect, Yukon-Koyukuk Census Area, Alaska, USAi
Regional Level Types
Tarn ProspectProspect
Yukon-Koyukuk Census AreaCensus Area
AlaskaState
USACountry

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Latitude & Longitude (WGS84):
63° 32' 6'' North , 154° 32' 20'' West
Latitude & Longitude (decimal):
63.53500,-154.53889
GeoHash:
G#: be617qhnn
GRN:
N43W52
Type:
Prospect
Köppen climate type:
Dfc : Subarctic climate
Mindat Locality ID:
200295
Long-form identifier:
mindat:1:2:200295:1
GUID (UUID V4):
0


See Copenhagen Hill (MD030), Frozen Creek (MD032), Pork Chop (MD031), and Mystery Mountains West (MD029) prospects.
Location: The Tarn prospect is situated on a steep cirque headwall in the north-central Mystery Mountains at an elevation of 3,200 feet (975 m) in Section 1, T. 23 S., R. 22 E., of the Kateel River Meridian. Location is accurate to within about 500 feet (152 m).
Geology: The Tarn prospect is within the eastern part of a northeast trending belt of porphyry-like copper-gold prospects that strike for 7 miles (11 km) in the central Mystery Mountains. The Tarn prospect consists of hydrothermal breccias in monzonitic dikes and small stocks that contain chalcopyrite, pyrite, tourmaline, and minor to trace arsenopyrite. Malichite occurs in hairline fractures in intrusive rocks; alteration and mineralization is not well developed in country-rock hornfels. The Tarn prospect is inferred to be Late Cretaceous, based on isotopic ages of plutonic rocks in Mystery Mountains (Moll and others, 1981). No assay data was found for this summary.
Workings: Regional exploration work conducted by WGM Inc. in the late 1970s discovered the Tarn and related prospects in the Mystery Mountains (Andrews, 1978). From 1988 to 1990, American Copper and Nickel Company conducted regional exploration, which included a detailed airborne geophysical survey. ASA Inc. continued detailed exploration work from 1991 to 1997 (DiMarchi and others, 1997). No drilling has taken place on the property, and no assay data was found for this summary.
Age: The Tarn prospect is inferred to be Late Cretaceous, based on isotopic ages of plutonic rocks in Mystery Mountains (Moll and others, 1981).
Alteration: Biotite in hornfels; ankerite in intrusions.
Reserves: None.

Commodities (Major) - Au, Cu; (Minor) - As, Sb
Development Status: No
Deposit Model: Porphyry Cu-Au (Cox and Singer, 1986; model no. 20c)

Select Mineral List Type

Standard Detailed Gallery Strunz Chemical Elements

Commodity List

This is a list of exploitable or exploited mineral commodities recorded at this locality.


Mineral List


3 valid minerals.

Gallery:

List of minerals arranged by Strunz 10th Edition classification

Group 2 - Sulphides and Sulfosalts
ⓘChalcopyrite2.CB.10aCuFeS2
ⓘArsenopyrite2.EB.20FeAsS
Group 4 - Oxides and Hydroxides
ⓘQuartz4.DA.05SiO2
Unclassified
ⓘ'Tourmaline'-AD3G6 (T6O18)(BO3)3X3Z

List of minerals for each chemical element

BBoron
Bⓘ TourmalineAD3G6 (T6O18)(BO3)3X3Z
OOxygen
Oⓘ QuartzSiO2
Oⓘ TourmalineAD3G6 (T6O18)(BO3)3X3Z
SiSilicon
Siⓘ QuartzSiO2
SSulfur
Sⓘ ArsenopyriteFeAsS
Sⓘ ChalcopyriteCuFeS2
FeIron
Feⓘ ArsenopyriteFeAsS
Feⓘ ChalcopyriteCuFeS2
CuCopper
Cuⓘ ChalcopyriteCuFeS2
AsArsenic
Asⓘ ArsenopyriteFeAsS

Other Databases

Link to USGS - Alaska:MD027

Other Regions, Features and Areas containing this locality

North AmericaContinent
North America PlateTectonic Plate
USA

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.

References

Andrews, Tom, 1978, Summary of Progress, Doyon Project, Mystery Mountains (Block 10): Anchorage, Alaska, WGM Inc., 24 p. (Held by Doyon, Limited, Fairbanks, Alaska, as proprietary report 78-42). DiMarchi, J.J., and Frantz, P.S., 1997, Annual Report for 1997-Doyon Option Lands, Block 10: ASA Inc.-Montague Gold Joint Venture Report, Volume II: Unpublished report, 189 p. (Report held by Doyon, Limited, Fairbanks, Alaska.) Moll, E.J., Silberman, M.L., and Patton, W.W. Jr., 1981, Chemistry, mineralogy, and K-Ar ages of igneous and metamorphic rocks of the Medfra quadrangle, Alaska: U.S. Geological Survey Open-File Report 80-811-C, 15 p., 2 sheets, scale 1:250,000.
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