Mineralium Deposita

, Volume 48, Issue 8, pp 991–1017 | Cite as

Genesis of the Au–Bi–Cu–As, Cu–Mo ± W, and base–metal Au–Ag mineralization at the Mountain Freegold (Yukon, Canada): constraints from Ar–Ar and Re–Os geochronology and Pb and stable isotope compositions

  • Thierry Bineli Betsi
  • David Lentz
  • Massimo Chiaradia
  • Kurt Kyser
  • Robert A. Creaser


The genesis of mineralized systems across the Mountain Freegold area, in the Dawson Range Cu–Au ± Mo Belt of the Tintina Au province was constrained using Pb and stable isotope compositions and Ar–Ar and Re–Os geochronology. Pb isotope compositions of sulfides span a wide compositional range (206Pb/204Pb, 18.669–19.861; 208Pb/204Pb, 38.400–39.238) that overlaps the compositions of the spatially associated igneous rocks, thus indicating a magmatic origin for Pb and probably the other metals. Sulfur isotopic compositions of sulfide minerals are broadly similar and their δ34S (Vienna-Canyon Diablo Troilite (V-CDT)) values range from −1.4 to 3.6 ‰ consistent with the magmatic range, with the exception of stibnite from a Au–Sb–quartz vein, which has δ34S values between −8.1 and −3.1 ‰. The δ34S values of sulfates coexisting with sulfide are between 11.2 and 14.2 ‰; whereas, those from the weathering zone range from 3.7 to 4.3 ‰, indicating supergene sulfates derived from oxidation of hypogene sulfides. The δ13C (Vienna Peedee Belemnite (VPDB)) values of carbonate range from −4.9 to 1.1 ‰ and are higher than magmatic values. The δ18O (V-SMOW) values of magmatic quartz phenocrysts and magmatic least-altered rocks vary between 6.2 and 10.1 ‰ and between 5.0 and 10.1 ‰, respectively, whereas altered magmatic rocks and hydrothermal minerals (quartz and magnetite) are relatively 18O-depleted (4.2 to 7.9 ‰ and −6.3 to 1.5 ‰, respectively). Hydrogen isotope compositions of both least-altered and altered igneous rock samples are D-depleted (from −133 to −161 ‰ Vienna-Standard Mean Ocean Water (V-SMOW)), consistent with differential magma degassing and/or post-crystallization exchange between the rocks and meteoric ground water. Zircon from a chlorite-altered dike has a U–Pb crystallization age of 108.7 ± 0.4 Ma; whereas, the same sample yielded a whole-rock Ar–Ar plateau age of 76.25 ± 0.53 Ma. Likewise, molybdenite Re–Os model ages range from 75.8 to 78.2 Ma, indicating the mineralizing events are genetically related to Late Cretaceous volcano-plutonic intrusions in the area. The molybdenite Re–Os ages difference between the nearby Nucleus (75.9 ± 0.3 to 76.2 ± 0.3 Ma) and Revenue (77.9 ± 0.3 to 78.2 ± 0.3 Ma) mineral occurrences suggests an episodic mineralized system with two pulses of hydrothermal fluids separated by at least 2 Ma. This, in combination with geological features suggest the Nucleus deposit represents the apical and younger portion of the Revenue–Nucleus magmatic-hydrothermal system and may suggest an evolution from the porphyry to the epithermal environments.


Lead Sulfur Oxygen Hydrogen And carbon isotopes Skarn Epithermal Porphyry Ar–Ar plateau age Re–Os geochronology Mountain Freegold Yukon 


  1. Aleinikoff JN, Lang Farmer G, Rye RO, Nokleberg WJ (2000) Isotopic evidence for the sources of Cretaceous and Tertiary granitic rocks, east-central Alaska: implications for the tectonic evolution of the Yukon–Tanana Terrane. Can J Earth Sci 37:945–956CrossRefGoogle Scholar
  2. Bachinski DJ (1969) Bond strength and sulfur isotope fractionation in coexisting sulfides. Econ Geol 64:56–65CrossRefGoogle Scholar
  3. Bacon CR, Adami LH, Lanphere MA (1989) Direct evidence for the origin of low-18O silicic magmas: quenched samples of a magma chamber’s partially-fused granitoid walls, Crater Lake, Oregon. Earth Planet Sci Lett 96:199–208CrossRefGoogle Scholar
  4. Bindeman IN, Valley JW (2000) Formation of low-δ18O rhyolites after caldera collapse at Yellowstone, Wyoming, USA. Geology 28:719–722CrossRefGoogle Scholar
  5. Bineli Betsi T, Bennett V (2010) New U–Pb age constraints at Freegold Mountain: Evidence for multiple phases of polymetallic mid- to Late Cretaceous mineralization. In: MacFarlane KE, Weston LH, Blackburn LR (eds) Yukon Exploration and Geology 2009, Yukon Geological Survey, pp 57–84Google Scholar
  6. Bineli Betsi T, Lentz D (2009) Petrogenesis of dykes related to Cu–Au & base-metal Au-Ag occurrences, Mt. Freegold area, Dawson Range, Yukon Territory, Canada. In: Lentz DR, Thorne KG, Beal K-L (eds) Proceedings of the 24th IAGS, Fredericton, Canada, pp 115–118Google Scholar
  7. Bineli Betsi T, Lentz D (2010) The nature of quartz eyes hosted by dykes associated with Au–Bi–As–Cu, Mo–Cu, and Base-metal–Au–Ag mineral occurrences in the Mountain Freegold region (Dawson Range), Yukon, Canada. J Geosci 55:347–368Google Scholar
  8. Bineli Betsi T, Lentz D (2011) Petrochemistry of subvolcanic dyke swarms associated with the Golden Revenue Au–Cu and the Stoddart Mo–Cu ± W mineralizations (Dawson Range, Yukon Territory, Canada) and implications for ore genesis. Ore Geol Rev 39:134–163CrossRefGoogle Scholar
  9. Bineli Betsi T, Lentz D (2012) Chemical composition of rock-forming minerals in granitoids associated with Au–Bi–Cu, Cu–Mo, and Au–Ag mineralization at the Freegold Mountain, Yukon, Canada: magmatic and hydrothermal fluid chemistry and petrogenetic implications. Int Geol Rev. doi:10.1080/00206814.2012.731767
  10. Bineli Betsi T, Lentz D, McInnes B, Evans N (2012) Emplacement ages and exhumation rates for intrusion-hosted Cu–Mo–Sb–Au mineral systems at freegold mountain (Yukon, Canada): assessment from U–Pb, Ar–Ar, and (U–Th)/He geochronometers. Can J Earth Sci 49:653–670. doi:10.1139/e2012-009 CrossRefGoogle Scholar
  11. Burnham CW (1979) Magma and hydrothermal fluids. In: Barnes HL (ed) Geochemistry of hydrothermal ore deposits, 2nd edn. Wiley, New York, pp 71–136Google Scholar
  12. Carlson GG (1987) Geology of Mount Nansen (115-1/3) and Stoddart Creek (115-1/6) map areas Dawson Range, Central Yukon: Indian and Northern affairs Canada, Northern affairs, Yukon Region, Open File 1987-2, 181 ppGoogle Scholar
  13. Clayton RN, Mayeda TK (1963) The use of bromine pentafluoride in the extraction of oxygen from oxides and silicates for isotopic analysis. Geochim Cosmochim Acta 27:43–52CrossRefGoogle Scholar
  14. Colpron MN, Nelson JL (2011) A digital atlas of terranes for the Northern Cordillera. BC GeoFile 2011Google Scholar
  15. Colpron MN, Nelson JL, Murphy DC (2006) A tectonostratigraphic framework for the Pericratonic terranes of the northern Canadian Cordillera. In: Colpron M, Nelson JL (eds) Paleozoic evolution and metallogeny of Pericratonic Terrranes at the ancient pacific margin of North America, Canadian and Alaskan Cordillera. Geol Assoc Can SP 45, pp 1–23Google Scholar
  16. De Hoog JCM, Taylor Bruce E, Van Bergen MJ (2009) Hydrogen-isotope systematics in degassing basaltic magma and application to Indonesian arc basalts. Chem Geol 266:256–266CrossRefGoogle Scholar
  17. Deyell CL, Rye RO, Landis GP, Bissig T (2005) Alunite and the role of magmatic fluids in the Tambo high-sulfidation deposit, El Indio–Pascua belt, Chile. Chem Geol 215:185–218CrossRefGoogle Scholar
  18. Einaudi MT, Hedenquist JW, Innan E (2003) Sulfidation state of fluids in active and extinct hydrothermal systems: transitions from porphyry to epithermal environments. Soc Econ Geol Spec Publ 10:285–314Google Scholar
  19. Field CW, Lombardi G (1972) Sulfur isotopic evidence for the supergene origin of alunite deposits, Tolfa district, Italy. Miner Deposita 7:113–125CrossRefGoogle Scholar
  20. Gerstenberger H, Haase G (1997) A highly effective emitter substance for mass spectrometric Pb isotope ratio determinations. Chem Geol 136:309–312CrossRefGoogle Scholar
  21. Godwin CI (1976) Casino. In: Brown AS (ed) Porphyry deposits of the Canadian Cordillera. CIM, special volume 15, pp 344–354Google Scholar
  22. Gordey SP, Makepeace AJ (2000) Bedrock geology, Yukon Territory. Geological Survey of Canada, Open File 3754, and Exploration and Geological Services Division, Yukon Region, Indian and Northern Affairs Canada, Open File 2001-1, 1:1 000 000 scaleGoogle Scholar
  23. Harris AC, Dunlap WJ, Reiners PW, Allen CM, Cooke DR, White NC, Campbell IH, Golding SD (2008) Multimillion year thermal history of a porphyry copper deposit: application of U–Pb, 40Ar/39Ar and (U–Th)/He chronometers, Bajo de la Alumbrera copper–gold deposit, Argentina. Miner Deposita 43:295–314CrossRefGoogle Scholar
  24. Hart CJR (2007) Reduced intrusion-related gold systems. In Goodfellow WD (ed) Mineral deposits of Canada: A synthesis of major deposit types, District Metallogeny, the evolution of geological provinces, and exploration methods. Geological Association of Canada, Mineral Deposits Division, Special Publication No. 5, pp 95–112Google Scholar
  25. Hefferman RS, Mortensen JK, Gabites JE, Sterenberg V (2005) Lead isotope signatures of Tintina Gold Province intrusions and associated mineral deposits from southeastern Yukon and southwestern Northwest Territories: Implications for exploration in the southeastern Tintina Gold Province. In: Emond DS, Lewis LL, and Bradshaw GD (eds) Yukon Exploration and Geology 2004, Yukon Geological Survey, pp 121–128Google Scholar
  26. Heinrich CA (2005) The physical and chemical evolution of low-salinity magmatic fluids at the porphyry to epithermal transition: a thermodynamic study. Miner Deposita 39:864–889CrossRefGoogle Scholar
  27. Holland HD, Malinin SD (1979) Oxygen and hydrogen isotope relationships in hydrothermal mineral deposits. In: Barnes HL (ed) Geochemistry of hydrothermal ore deposits, 2nd edn. Wiley, New York, pp 461–508Google Scholar
  28. Javoy M (1997) Stable isotope and geothermometry. J Geol Soc 133:609–636CrossRefGoogle Scholar
  29. Jensen ML, Ashley RP, Albers JP (1971) Primary and secondary sulfates at Goldfield, Nevada. Econ Geol 66:618–626CrossRefGoogle Scholar
  30. Johnston ST (1995) Geological compilation with interpretation from geophysical surveys of the northern Dawson Range, central Yukon (115-J/9 and 115- J/10, 115-J/12, 1: 100 000-scale map). Exploration and Geological Services Division, Yukon Region, Indian and Northern Affairs Canada, Open File 1995-2 (G), 171 ppGoogle Scholar
  31. Koppers AP (2002) ArArCALC – software for 40Ar/39Ar age calculations. Comput Geosci 28:605–619CrossRefGoogle Scholar
  32. Kyser TK (1986) Stable isotope variations in the mantle. In: Valley JW, Taylor HP Jr, O’neil JR (eds) Stable isotopes in high temperature geological processes. Mineralogical Society of America Reviews in Mineralogy 16: 141–164Google Scholar
  33. Lang JR, Baker T (2001) Intrusion-related gold systems: the present level of understanding. Miner Deposita 36:477–489CrossRefGoogle Scholar
  34. Longerich HP (1995) The analysis of pressed pellets of geological samples using wavelength dispersive X-ray fluorescence spectrometry. X-Ray Spectrom 24:123–136CrossRefGoogle Scholar
  35. Ludwig KR (2003) Isoplot 3.09 A Geochronological Toolkit for Microsoft Excel. Berkeley Geochronology Center, Special Publication No. 4, 71 ppGoogle Scholar
  36. Maloof TL, Baker T, Thompson JF (2001) The Dublin Gulch intrusion-hosted gold deposit. Tombstone Plutonic suite, Yukon Territory, Canada. Miner Deposita 36:583–593CrossRefGoogle Scholar
  37. Matsuhisa Y, Goldsmith JR, Clayton RN (1979) Oxygen isotope fractionation in the system quartz-albite-anorthite-water. Geochim Cosmochim Acta 43:1131–1140CrossRefGoogle Scholar
  38. McCausland PJA, Symons DTA, Hart CJR, Blackburn WH (2001) Paleomagnetic study of the Late Cretaceous Seymour Creek stock, Yukon: Minimal geotectonic motion of the Yukon-Tanana Terrane. In: Emond DS, Weston LH (eds) Yukon Exploration and Geology 2000, Exploration and Geological Services Division, Yukon Region, Indian and Northern Affairs Canada, pp 207–216Google Scholar
  39. McInnes BIA, Goodfellow WD, Crocket JH, McNutt RH (1988) Geology, geochemistry and geochronology of subvolcanic intrusions associated with gold deposits at Freegold Mountain, Dawson Range, Yukon. Geological Survey of Canada, Current Research 88-1E, pp 137–151Google Scholar
  40. Mortensen JK, Appel V, Hart JR (2003) Geological and U–Pb constraints on base and precious metal vein systems in the Mount Nansen area, eastern Dawson Range, Yukon. Yukon Exploration and Geology 2002, pp 165–174Google Scholar
  41. Muntean JL, Einaudi M (2001) Porphyry-epithermal transition: Maricunga Belt, Northern Chile. Econ Geol 96:743–772CrossRefGoogle Scholar
  42. Ohmoto H, Rye RO (1979) Isotopes of sulfur and carbon. In: Barnes HL (ed) Geochemistry of hydrothermal ore deposits, 2nd edn. Wiley, New York, pp 509–567Google Scholar
  43. Payne JG, Gonzalez RA, Akhurst K, Sisson WG (1987) Geology of Colorado Creek (115-J/10), Selwyn River (115-J/9), and Prospector Mountain (115-1/5) map areas, western Dawson Range, west-central Yukon: Exploration and Geological Services Division, Indian and Northern Affairs Canada, Yukon Region, Open File 1987-3, 141 pGoogle Scholar
  44. Phillips GN (1986) Geology and alteration in the Golden Mile, Kalgoorlie. Econ Geol 91:779–808CrossRefGoogle Scholar
  45. Pin C, Briot D, Bassin C, Poitrasson F (1994) Concomitant separation of strontium and samarium–neodymium for isotopic analysis in silicate samples, based on specific extraction chromatography. Anal Chim Acta 298:209–217CrossRefGoogle Scholar
  46. Pineau F, Shilobreeva S, Kadik A, Javoy M (1998) Water solubility and D/H fractionation in the system basaltic andesite—H2O at 1250 °C and between 0.5 and 3 kbars. Chem Geol 147:173–184CrossRefGoogle Scholar
  47. Pudack C, Halter WE, Heinrich CA, Pettke T (2009) Evolution of magmatic vapor to gold-rich epithermal liquid: the porphyry to epithermal transition at Nevados de Famatina, northwest Argentina. Econ Geol 104:449–477CrossRefGoogle Scholar
  48. Quin SP, Mercer BJ (2008) The Minto copper-gold deposit - IOCG or what? Geological Association of Canada, Québec 2008, Abstracts, vol. 33, p 140Google Scholar
  49. Renne PR, Swisher CC, Deino AL, Karner DB, Owens T, DePaolo DJ (1998) Intercalibration of standards, absolute ages and uncertainties in 40Ar/39Ar dating. Chem Geol 145(1–2):117–152CrossRefGoogle Scholar
  50. Ripperdan RL (2001) Stratigraphic variation in marine carbonate carbon isotope ratios. In: Valley JW, Cole DR (eds.) Stable isotope geochemistry: reviews in mineral and geochem 43, pp 637–662Google Scholar
  51. Rye RO (2005) A review of the stable-isotope geochemistry of sulfate minerals in selected igneous environments and related hydrothermal systems. Chem Geol 215:5–36CrossRefGoogle Scholar
  52. Sakai H (1968) Isotopic properties of sulfur compounds in hydrothermal processes. Geochem J 2:29–49CrossRefGoogle Scholar
  53. Sakai H, Gunnlaugsson E, Tomasson J, Rousse JE (1980) Sulfur isotope systematic in Icelandic geothermal systems and influence of seawater circulation at Reykjanes. Geochim Cosmochim Acta 44:1223–1231CrossRefGoogle Scholar
  54. Seal RR II (2006) Sulfur isotope geochemistry of sulfide minerals. Rev Mineral Geochem 61:633–677CrossRefGoogle Scholar
  55. Selby D, Creaser RA (2001) Late and mid-Cretaceous mineralization in the northern Canadian Cordillera: constraints from Re–Os molybdenite dates. Econ Geol 96:1461–1467CrossRefGoogle Scholar
  56. Selby D, Creaser RA (2004) Macroscale NTIMS and microscale LA-MC-ICP-MS Re–Os isotopic analysis of molybdenite: Testing spatial restrictions for reliable Re–Os age determinations, and implications for the decoupling of Re and Os within molybdenite. Geochim Cosmochim Acta 68:3897–3908CrossRefGoogle Scholar
  57. Selby D, Creaser RA, Nesbit EB (1999) Major and trace element compositions and Sr-Nd-Pb systematics of crystalline rocks from the Dawson Range, Yukon, Canada. Can J Earth Sci 36:1463–1481CrossRefGoogle Scholar
  58. Selby D, Creaser RA, Hart CJR, Rombach CS, Thompson JFH, Smith MT, Bakke AA, Goldfarb RJ (2002) Absolute timing of sulfide and gold mineralization: a comparison of Re–Os molybdenite and Ar–Ar mica methods from the Tintina Gold Belt, Alaska. Geology 30(9):791–794CrossRefGoogle Scholar
  59. Sillitoe RH, Hedenquist JW (2003) Linkages between volcanotectonic settings, ore fluid compositions, and epithermal precious metal deposits. Soc Econ Geol Spec Publ 10:315–343Google Scholar
  60. Sinclair WD, Cathro RJ, Jensen EM (1981) The Cash porphyry copper-molybdenum deposit, Dawson Range, Yukon Territory. Can Min Metall Bull 74(832):1–10Google Scholar
  61. Smuk KA (1999) Metallogeny of epithermal gold and base metal veins of the southern Dawson Range, Yukon: Unpublished MSc. thesis, McGill University, Montreal, Quebec, 155 ppGoogle Scholar
  62. Smuk KA, Williams-Jones AE, Francis D (1997) The Carmacks hydrothermal event: An alteration study in the southern Dawson Range. In: Yukon Geology 1996, Exploration and Geological Services Division, Yukon Region, Indian and Northern Affairs, Canada, pp 92–106Google Scholar
  63. Tafti R, Mortensen JK (2004) Early Jurassic porphyry(?) copper (-gold) deposits at Minto and Williams Creek, Carmacks Copper Belt, western Yukon. In: Emond DS, Lewis LL (eds.) Yukon Exploration and Geology 2003, Yukon Geological Survey, pp 289–303Google Scholar
  64. Taylor BE (1986) Magmatic volatiles: Isotopic variation of C, H, and S stable isotopes in high temperature geological processes. In: Valley JW, Taylor HP, O’Neil JR (eds) Rev Mineral 16, pp 185–225Google Scholar
  65. Taylor HP Jr. (1974) Oxygen and hydrogen isotope evidence for large-scale circulation and interaction between ground waters and igneous intrusions, with particular reference to the San juan volcanic field, Colorado. In: Hoffman AW, Gileti BJ, Yoder HSJr., Yund RA (eds) Geochemical transport and Kinematics: Washington, DC, Carnegie Institution Wash, pp 299–324Google Scholar
  66. Taylor HP Jr, Sheppard SMF (1986) Igneous Rocks I: Processes of isotopic fractionation and isotope systematic. In: Valley JW, Taylor HP, O’Neil JR (eds) Stable isotopes in high temperature geological processes. Rev Miner 16, pp 227–269Google Scholar
  67. Taylor HP Jr et al (1979) Oxygen and hydrogen isotope relationships in hydrothermal mineral deposits. In: Barness HL (ed) Geochemistry of hydrothermal ore deposits. Wiley, New York, pp 236–277Google Scholar
  68. Taylor BE, Eichelberger JC, Westrich HR (1983) Hydrogen isotopic evidence of rhyolitic magma degassing during shallow intrusion and eruption. Nature 306(8):541–545CrossRefGoogle Scholar
  69. Tempelman-Kluit DJ (1974) Reconnaissance geology of Aishihik Lake, Snag and part of Stewart River map-areas, west-central Yukon (115A, 115F, 115G and 115K). Geol Surv Can 73:41–97Google Scholar
  70. Tempelman-Kluit DJ (1984) Geology, Laberge (105E) and Carmacks (105I), Yukon Territory: Geological Survey of Canada, Open File 1101, maps with legends, 1:250 000 scaleGoogle Scholar
  71. Thompson JFH, Sillitoe RH, Baker T, Lang JR, Mortensen JK (1999) Intrusion-related gold deposits associated with tungsten-tin provinces. Miner Deposita 34:323–334CrossRefGoogle Scholar
  72. Todt W, Cliff RA, Hanser A, Hofmann AW (1996) Evaluation of a 202Pb–205Pb double spike for high-precision lead isotope analysis. In: Basu A, Hart SR (eds) Earth processes, reading the isotopic code: Am Geoph, Un Geoph Mon 95, pp 429–437Google Scholar
  73. Tosdal RM, Wooden JL, Bouse R (1999) Lead isotopes, ore deposits, and metallogenic terranes. In: Lambert DD, Ruiz J (eds) Application of radiogenic isotopes to ore deposit research and exploration. Rev Econ Geol, pp 1–25Google Scholar
  74. Vigneresse JL (2007) The role of discontinuous magma inputs in felsic magma and ore generation. Ore Geol Rev 30:181–216CrossRefGoogle Scholar
  75. Yang XM, Lentz DR (2010) Sulfur isotopic systematic of granitoids from southwestern New Brunswick, Canada: implications for magmatic-hydrothermal processes, redox conditions, and gold mineralization. Miner Deposita 45:795–816CrossRefGoogle Scholar
  76. Zartman RE, Doe BR (1981) Plumbotectonics, the model. Tectonophysics 75:135–162CrossRefGoogle Scholar
  77. Zimbelman DR, Rye RO, Breit G (2005) Origin of secondary sulfate minerals in active andesitic stratovolcanoes. Chem Geol 215:37–60CrossRefGoogle Scholar

Copyright information

© Springer-Verlag Berlin Heidelberg 2013

Authors and Affiliations

  • Thierry Bineli Betsi
    • 1
  • David Lentz
    • 1
  • Massimo Chiaradia
    • 2
  • Kurt Kyser
    • 3
  • Robert A. Creaser
    • 4
  1. 1.Department of Earth SciencesUniversity of New BrunswickNew BrunswickCanada
  2. 2.Département de MinéralogieUniversité de GenèveGeneva 4Switzerland
  3. 3.Department of Geological SciencesQueens UniversityQueen’s KingstonCanada
  4. 4.Department of Earth and Atmospheric SciencesUniversity of AlbertaAlbertaCanada

Personalised recommendations