Oyu Tolgoi

Porphyry copper (Cu-Au) deposit in Ömnögovi, Mongolia

Names and other identifiers

Alternate names Oyuu Tolgoi, Turquoise Hill
Tract name Oyu Tolgoi (142pCu8506)
Included sites Heruga, Heruga North, South Oyu, Southwest Oyu, Central Oyu, Hugo Dummett
Site status deposit

Geographic location

Country Mongolia
State or province Ömnögovi
Geographic location 106.8535, 43.0136
Geologic map unit 106.8535, 43.0136
Nearby data

Geologic information

Deposit type Porphyry copper
Deposit subtype Cu-Au
Age (Ma) 372Ma
Age determination method Re-Os molybdenite
Age range 372 ±1.2 Ma (Re-Os molybdenite); 372 ±3 Ma (unknown)
Age reference Zhang and others (2006); Khashgerel and others (2009)
Minerals alunite, apatite, barite, biotite, bornite, carbonate, chrysocolla, arsenosulvanite [Cu3(As,V)S4], chalcocite, chlorite, copper, covellite, chalcopyrite, epidote, fluorite, hematite, goethite/limonite, kaolinite/illite/dickite, malachite, magnetite, molybdenite, pyrite, pyrophyllite, rutile, sericite, sphalerite, svanbergite [SrAlll3(PO4)(SO4)(OH6)], tennantite, tenorite, zunyite
Associated rocks quartz monzodiorite, andesite dike, breccia, diorite, monzodiorite porphyry, syenite dike, syenite porphyry, syenodiorite porphyry,argillite, granite, granodiorite, shale, andesite, andesite flow breccia, andesite porphyry, basalt, basaltic andesite, carbonaceous claystone, conglomerate, dacite, lapilli tuff, pillow basalt, rhyolite, sandstone, syenite, tuffaceous siltstone, tuffite
Tectonic setting island arc
Stratigraphic age Late Devonian

Commodity and development information

Development status Prospect
Major commodities Cu, Mo
Minor commodities Au
Tonnage (Mt) 3,755Mt
Cu grade (%) 0.98%
Mo grade (%) 0.01%
Au grade (g/t) 0.38g/t
Contained copper 37,000,000t
Gold-Moly ratio 40

Reference information

Comments G-T March 2010, from Ivanhoe Integrated Development Plan (IDP-10). Grades calculated by weighted average; Mo grade an estimate based on partial information. High sulphidation style mineralization has partially telescoped on to underlying Cu-Au porphyries, mineralizing intrusions are cross-cut by later biotite-granodiorites. Discovered by D. P. Cox, USGS emeritus.
Study area name Central Asian Orogenic Belt
References Singer and others (2008); Ivanhoe Mines Ltd. (2003a); Ivanhoe Mines Ltd. (2010a); Ivanhoe Mines Ltd. (2010b); Ivanhoe Mines Ltd. (2011); Kavalieris and others (2011); Khashgerel and others (2009); Kirwin (2006); Kirwin, Foster and others (2005); Perelló, Cox and others (2001); Kirkham and Dunne (2000); Dejidmaa and others (2002); Nokleberg and others (2003); Nokleberg and others (2006); Zhang and others (2006)
Site reference Mihalasky, Ludington, Hammarstrom, and others (2015)
Dejidmaa, G., Bujinlkham, B., Ganbaatar, T., Oyuntuya, N., Enkhtuya, B., Eviihuu, A., and Monkh-Erdene, N., 2002, Distribution map of mineral deposits and occurrences in Mongolia: Ulaanbaatar, Mongolia Mineral Resources Authority, Geologic Information Center, 540 p., 12 sheets, scale 1:1,000,000.
Ivanhoe Mines Ltd., 2003a, Independent resource estimate confirms a world-class gold and copper porphyry discovery at Turquoise Hill, Mongolia: Ivanhoe Mines Ltd. press release, February 26, 2003, 1 p., accessed December 4, 2013, at http://www.turquoisehill.com/s/news_releases.asp?ReportID=375332.Ivanhoe Mines Ltd., 2010a, Building the future today at Oyu Tolgoi—Integrated development plan 2010: Ivanhoe Mines Ltd. Web page accessed October 13, 2011, at http://www.ivanhoemines.com/i/pdf/ppt/IDP_2010_PPT_May_11_2010.pdf. [Web page no longer available.] (Similar title available at http://www.turquoisehill.com/i/pdf/2010May11.pdf.)Ivanhoe Mines Ltd., 2010b, Oyu Tolgoi project—Technical report, June 2010: National Instrument 43-101 Technical Report prepared by AMEC Minproc for Ivanhoe Mines Ltd., accessed December 4, 2013, at http://www.turquoisehill.com/i/pdf/IDP10_June062010.PDF.
Ivanhoe Mines Ltd., 2011, Building the dream—Corporate presentation, November 2011: Ivanhoe Mines Ltd. presentation, accessed June 4, 2012, at http://www.ivanhoemines.com/i/pdf/Ivanhoe_Master_November_9.pdf. [Web page no longer available.]
Kavalieris, Imants; Rinchin, Oyunchimeg; Gombojav, Jargaljav; Gombosuren, Niislelkhuu; Crane, David; Orssich, Cyrill; and Khashgerel, Bat-Erdene, 2011, Characteristics of the Oyu Tolgoi porphyry deposits, south Gobi, Mongolia, in Society for Geology Applied to Mineral Deposits (SGA) Biennial Meeting, 11th, Antofagasta, Chile, September 26–29, 2011, Proceedings: Antofagasta, Chile, Ediciones Universidad Catolica del Norte, p. 343–345. (Abstract also available at https://www.e-sga.org/index.php?id=231&redirect=79%2522%2520onfocus%253D%2522blurLink%2528this%2529%253B&tx_commerce_pi1%5BshowUid%5D=1776&tx_commerce_pi1%5BcatUid%5D=45&cHash=5ede645ed7.)Khashgerel, Bat-Erdene, Rye, R.O., Kavelieris, Imants, and Hayashi, Ken-ichiro., 2009, The sericitic to advanced argillic transition—Stable isotope and mineralogical characteristics from the Hugo Dummet porphyry Cu-Au deposit, Oyu Tolgoi district, Mongolia: Economic Geology, v. 104, p. 1087–1110. (Also available at http://dx.doi.org/10.2113/gsecongeo.104.8.1087.)Kirkham, R.V., and Dunne, K.P.E., comps., 2000, World distribution of porphyry, porphyry-associated skarn, and bulk-tonnage epithermal deposits and occurrences: Canada Geological Survey Open File 3792a, 26 p. and 1 diskette. (Also available at http://dx.doi.org/10.4095/211229.)Kirwin, D.J., 2006, The giant Oyu Tolgoi porphyry copper-gold deposit discovery history and exploration implications, south Gobi, in Cherkasov, S.V., ed., Extended abstracts: International Association on the Genesis of Ore Deposits (IAGOD) Quadrennial Symposium, 12th, Moscow, Russia, August 20–24, 2006 [Proceedings], CD-ROM. (Also available at http://www.publish.csiro.au/?act=view_file&file_id=ASEG2006ab087.pdf.)
Kirwin, D.J., Foster, C.N., Kavalieris, I., Grane, D., Orssich, C., Panther, C., Gramajav, D., Munkhbat, T.O., and Niiselekhuu, G., 2005, The Oyu Tolgoi copper-gold porphyry deposits, south Gobi, Mongolia, in Seltmann, Reimar; Gerel, Ochir; and Kirwin, Douglas, eds., Geodynamics and metallogeny of Mongolia with a special emphasis on copper and gold deposits: London, British Natural History Museum, Centre for Russian and Central Eurasian Mineral Studies (CERCAMS), IAGOD Guidebook Series 11, p. 155–168.
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/.)Nokleberg, W.J., Miller, R.J., and Diggles, M.F., eds., 2006, Geographic information systems (GIS) spatial data compilation of geodynamic, tectonic, metallogenic, mineral deposit, and geophysical maps and associated descriptive data for northeast Asia: U.S. Geological Survey Open-File Report 2006-1150, 11 p. and digital data, CD-ROM. (Also available at http://pubs.usgs.gov/of/2006/1150/.)Perelló, José; Cox, Dennis; Garamjav, Dondog; Sanjdorj, Samand; Diakov, Sergei; Schissel, Donald; Munkhbat, Tumur-Ochir; and Oyun, Gonchig, 2001, Oyu Tolgoi, Mongolia—Silurian-Devonian porphyry Cu-Au-(Mo) and high-sulfidation Cu mineralization with aCretaceous chalcocite blanket: Economic Geology, v. 96, p. 1407–1428. (Also available at http://dx.doi.org/10.2113/gsecongeo.96.6.1407.)Singer, D.A., Berger, V.I., and Moring, B.C., 2008, Porphyry copper deposits of the world—Database and grade and tonnage models, 2008: U.S. Geological Survey Open-File Report 2008-1155, [45] p. and digital data, accessed December 31, 2013, at http://pubs.usgs.gov/of/2008/1155/.Zhang, Lianchang; Xiao, Wenjiao; Qin, Kezhang; and Zhang, Qi, 2006, The adakite connection of the Tuwu-Yandong copper porphyry belt, eastern Tianshan, NW China—Trace element and Sr-Nd-Pb isotope geochemistry: Mineralium Deposita, v. 41, p. 188–200. (Also available at http://dx.doi.org/10.1007/s00126-006-0058-6.)