Oyut Tolgoi

Porphyry copper prospect in Dzavhan, Mongolia

Names and other identifiers

Alternate names Oyut Tolgoi 2
Tract name Erdenet (142pCu8508a)
Site status prospect

Geographic location

Country Mongolia
State or province Dzavhan
Geographic location 95.975, 49.2667
Geologic map unit 95.975, 49.2667
Nearby data

Geologic information

Deposit type Porphyry copper
Age determination method Geologic inference
Age range ~290 Ma (Variscan orogeny)
Age reference geologic inference
Minerals arsenopyrite, bornite, chalcocite, chalcopyrite, ilmenite, magnetite, millerite, native gold, pentlandite, pyrite, sphalerite
Associated rocks gabbro and hornblendite stocks intrude gneiss, schist and amphibolite
Tectonic setting continental margin
Stratigraphic age Early Permian

Commodity and development information

Development status Prospect
Major commodities Cu
Gold-Moly ratio -9999

Reference information

Comments Four main ore zones form an E–W trend with average grades of (1) 0.36% Cu, 0.039% Ni and 0.04% Co; (2) 0.52% Cu, 05% Ni and 0.006% Co, with two samples containing 0.16 g/t Pd and 0.4 g/t Au; (3) 0.27% Cu and 0.031% Ni; and (4) 0.38-0.78% Cu. Consists of Cu sulfides in a Middle Cambrian gabbro and hornblendite stocks that occur along the Khangai fault system for 6.0 km and ranges up to 1.5 km wide. The sulfides occur around of amphibole grains, and in rare small nests and disseminations in quartzand quartz-feldspar veins in outer contact zone of some small stocks. See Nokleberg and others (2003) for additonal information. Middle Cambrian gabbro and hornblendite stocks intrude Paleoproterozoic gneiss, schist and amphibolite.
Study area name Central Asian Orogenic Belt
References Nokleberg and others (1999); Nokleberg and others (2003); Hedenquist and Daneshfar (2003); United Nations (1999)
Site reference Mihalasky, Ludington, Hammarstrom, and others (2015)
Hedenquist, J.W., and Daneshfar, B., 2003, Mineral potential of central and east Asia, in Basis for mining investment in transition economy countries: Washington, D.C., Mining Journal Publishing, World Bank Group, Mining Department, 79 p.
Nokleberg, W.J., Naumova, V.V., Kuzmin, M.I., and Bounaeva, T.V., eds., 1999, Preliminary publications book 1 from project on mineral resources, metallogenesis, and tectonics of northeast Asia: U.S. Geological Survey Open-File Report 99-165, 6 p. and digital data, CD-ROM. (Also available at http://pubs.usgs.gov/of/1999/of99-165/.)Nokleberg, W.J., Bounaeva, T.M., Miller, R.J., Seminskiy, Z.V., and Diggles, M.F. eds., 2003, Significant metalliferous and selected non-metalliferous lode deposits, and selected placer districts of northeast Asia: U.S. Geological Survey Open-File Report 03-220, 422 p., CD-ROM. (Also available at http://pubs.usgs.gov/of/2003/of03-220/.)
United Nations, 1999, Geology and mineral resources of Mongolia: New York, United Nations, Economic and Social Commission for Asia and the Pacific (ESCAP), Atlas of Mineral Resources of the ESCAP Region, v. 14, 192 p., scale 1:3,000,000.