Skip to main content
Log in

Copper mobility in the Eastern Creek Volcanics, Mount Isa, Australia: evidence from laser ablation ICP-MS of iron-titanium oxides

  • Article
  • Published:
Mineralium Deposita Aims and scope Submit manuscript

Abstract

The Palaeoproterozoic Eastern Creek Volcanics are a series of copper-rich tholeiitic basalts which occur adjacent to the giant sediment-hosted Mount Isa copper deposit in Queensland, Australia. The volcanic rocks are often cited as the source of metals for the deposit. New laser ablation ICP-MS analyses of iron–titanium oxides from the basalts provide evidence for the local mobilisation of copper during regional greenschist facies metamorphism. This interpretation is based on the observation that copper-bearing magmatic titanomagnetite was destabilised during greenschist facies metamorphism, and the new magnetite which crystallised was copper poor. Petrological observations, regional geochemical signatures and geochemical modelling suggest that the mobilised copper was concentrated in syn-metamorphic epidote-rich alteration zones, creating a pre-concentration of copper before the main mineralisation event at Mount Isa. Geochemical modelling demonstrates this process is enhanced by the addition of CO2 from adjacent carbonate-rich sediments during metamorphic devolatilisation. Regional geochemical data illustrate elevated copper concentrations in epidote-rich zones (high CaO), but where these zones are overprinted by potassic alteration (high K2O), copper is depleted. A two-stage model is proposed whereby after metamorphic copper enrichment in epidote–titanite alteration zones, an oxidised potassium-rich fluid leached copper from the epidote-altered metabasalts and deposited it in the overlying sedimentary rocks to form the Mount Isa copper deposit. This ore-forming fluid is expressed regionally as potassium feldspar-rich veins and locally as biotite-rich alteration, which formed around major fluid conduits between the metabasalt metal source rocks and the overlying deposit host sequence. This model is consistent with the remobilisation of copper from mafic source rocks, as has been found at other world-class copper deposits.

This is a preview of subscription content, log in via an institution to check access.

Access this article

Price excludes VAT (USA)
Tax calculation will be finalised during checkout.

Instant access to the full article PDF.

Fig. 1
Fig. 2
Fig. 3
Fig. 4
Fig. 5
Fig. 6
Fig. 7
Fig. 8
Fig. 9

Similar content being viewed by others

References

  • Andrew AS, Heinrich CA, Wilkins RWT, Patterson DJ (1989) Sulfur isotope systematics of copper ore formation at Mount Isa, Australia. Econ Geol 84:1614–1626

    Google Scholar 

  • Bain JHC, Heinrich CA, Henderson GAM (1992) Stratigraphy, structure, and metasomatism of the Haslingden Group, east Moondarra area, Mount Isa: a deformed and mineralised Proterozoic multistage rift-sag sequence. In: Stewart AJ, Blake DH (eds) Detailed studies of the Mount Isa Inlier; Australian Geological Survey Organisation Bulletin 243, pp 125–136

  • Bethke CM (1998) The Geochemist’s Workbench. University of Illinois, IL

    Google Scholar 

  • Blake DH, Stewart AJ (1992) Stratigraphic and tectonic framework, Mount Isa Inlier. In: Stewart AJ, Blake DH (eds) Detailed studies of the Mount Isa Inlier; Australian Geological Survey Organisation Bulletin 243. Australian Government Publishing Service, Canberra, pp 1–11

    Google Scholar 

  • Bultitude RJ, Wyborn LAI (1982) Distribution and geochemistry of volcanic rocks in the Duchess-Urandangi region, Queensland. BMR J Aust Geol Geophys 7:99–112

    Google Scholar 

  • Cassidy KF, Groves DI, Binns RA (1988) Manganoan ilmenite formed during regional metamorphism of Archean mafic and ultramafic rocks from Western Australia. Can Mineral 26:999–1012

    Google Scholar 

  • Connors KA, Page RW (1995) Relationships between magmatism, metamorphism and deformation in the western Mount Isa Inlier, Australia. Precambrian Res 71:131–153

    Article  Google Scholar 

  • Connors KA, Proffett JM, Lister G, Scott RJ, Oliver NHS, Young D (1992) Geology of the Mount Novit Ranges, southwest of Mount Isa mine. In: Stewart AJ, Blake DH (eds) Detailed studies of the Mount Isa Inlier; Australian Geological Survey Organisation Bulletin 243, pp 137–160

  • Cooke DR, Bull SW, Donovan S, Rogers JR (1998) K-metasomatism and base metal depletion in volcanic rocks from the McArthur Basin, Northern Territory—implications for base metal mineralization. Econ Geol 93:1237–1263

    Google Scholar 

  • Crocket JH (2002) Platinum-group element geochemistry of mafic and ultramafic rocks. In: Cabri LJ (ed) The geology, geochemistry, mineralogy and mineral beneficiation of platinum-group elements. Canadian Institute of Mining, Metallurgy and Petroleum, Canada, pp 177–210

    Google Scholar 

  • Derrick GM (1976) Mary Kathleen, Queensland 1:100,000 geological map. Geoscience Australia, Canberra

    Google Scholar 

  • Duncan RJ, Wilde AR, Bassano K, Maas R (2006) Geochronological constraints on tourmaline formation in the Western Fold Belt of the Mount Isa Inlier, Australia: evidence for large-scale metamorphism at 1.57 Ga? Precambrian Res 146:120–137

    Article  Google Scholar 

  • Farquharson RB, Richards JR (1974) U–Th–Pb isotope systematics related to igneous rocks and ore Pb, Mount Isa, Queensland. Miner Depos 9:339–356

    Article  Google Scholar 

  • Frietsch R (1970) Trace elements in magnetite and hematite mainly from northern Sweden, Aarsbok. Sveriges Geologiska Undersoekning 64:136

    Google Scholar 

  • Frost BR, Lindsley DH (1991) Occurrence of iron–titanium oxides in igneous rocks. In: Lindsley DH (ed) Oxide minerals: petrologic and magnetic significance. Rev Miner 25:433–468

  • Goldschmidt VM (1954) Geochemistry. Oxford University Press, London

    Google Scholar 

  • Grant JA (1986) The isocon diagram—a simple solution to Gresens’ equation for metasomatic alteration. Econ Geol 81:1976–1982

    Google Scholar 

  • Gregory MJ (2005) The geological evolution of the Eastern Creek Volcanics, Mount Isa, Australia and implications for the Mount Isa copper deposit. Ph.D. thesis, Monash University, Melbourne

  • Gulson BL, Perkins WG, Mizon KJ (1983) Lead isotope studies bearing on the genesis of copper orebodies at Mount Isa, Queensland. Econ Geol 78:1466–1504

    Google Scholar 

  • Hand M, Rubatto D (2002) The scale of the thermal problem in the Mt. Isa Inlier. In: Preiss VP (ed) Geoscience 2002: expanding horizons. 16th Australian geological convention, Adelaide, South Australia, pp 173

    Google Scholar 

  • Hannan KW, Golding SD, Herbert HK, Krouse HR (1993) Contrasting alteration assemblages in metabasites from Mount Isa, Queensland; implications for copper ore genesis. Econ Geol 88:1135–1175

    Google Scholar 

  • Haynes DW, Bloom MS (1987) Stratiform copper deposits hosted by low-energy sediments: III. Aspects of metal transport. Econ Geol 82:635–648

    Google Scholar 

  • Heinrich CA, Bain JHC, Mernagh TP, Wyborn LAI, Andrew AS, Waring CL (1995) Fluid and mass transfer during metabasalt alteration and copper mineralization at Mount Isa, Australia. Econ Geol 90:705–730

    Google Scholar 

  • Hill RM (1978) Mount Isa Queensland 1:100,000 geological map. Geoscience Australia, Canberra

    Google Scholar 

  • Johnson JP, McCulloch MT (1995) Sources of mineralising fluids for the Olympic Dam deposit (South Australia): Sm–Nd isotopic constraints. Chem Geol 121:177–199

    Article  Google Scholar 

  • Jowett EC (1986) Genesis of Kupferschiefer Cu–Ag deposits by convective flow of Rotliegende brines during Triassic rifting. Econ Geol 81:1823–1837

    Google Scholar 

  • Leaman DE (1991) Geophysical constraints on structure and alteration of the Eastern Creek Volcanics, Mt. Isa, Queensland. Aust J Earth Sci 38:457–472

    Google Scholar 

  • Lister GS, O’Dea MG, Somaia I (1999) A tale of two synclines; rifting, inversion and transpressional popouts at Lake Julius, northwestern Mt. Isa Terrane, Queensland. Aust J Earth Sci 46:233–250

    Article  Google Scholar 

  • Muir MD (1981) The microfossils from the Proterozoic Urquhart Shale, Mount Isa, Queensland, and their significance in relation to the depositional environment, diagenesis, and mineralisation. Minera Depos 16:51–58

    Google Scholar 

  • Neudert MK, Russell RE (1981) Shallow water and hypersaline features from the middle Proterozoic Mt. Isa sequence. Nature 293:284–286

    Article  Google Scholar 

  • Neumann N, Southgate PN, McIntyre A, Gibson G (2005) New data on rock ages from Mt. Isa Inlier. AUSGEO News 78

  • O’Dea MG, Lister G, MacCready T, Betts PG, Oliver NHS, Pound KS, Huang W, Valenta RK (1997) Geodynamic evolution of the Proterozoic Mount Isa terrain. In: Burg J-P, Ford M (eds) Orogeny through time. Geol Soc Lond Spec Publ 121:99–122

  • Page RW, Sweet IP (1998) Geochronology of basin phases in the western Mt. Isa Inlier, and correlation with the McArthur Basin—application of radiogenic isotopes to the study of Australian ore deposits. Aust J Earth Sci 45:219–232

    Google Scholar 

  • Page RW, Jackson MJ, Krassay AA (2000) Constraining sequence stratigraphy in North Australian basins; SHRIMP U–Pb zircon geochronology between Mt. Isa and McArthur River. Aust J Earth Sci 47:431–459

    Article  Google Scholar 

  • Painter MGM, Golding SD, Hannan KW, Neudert MK (1999) Sedimentologic, petrographic, and sulfur isotope constraints on fine-grained pyrite formation at Mount Isa Mine and environs, Northwest Queensland, Australia. Econ Geol 94:883–912

    Google Scholar 

  • Pearce NJG, Perkins WT, Westgate JA, Gorton MP, Jackson SE, Neal CR, Chenery SP (1997) A compilation of new and published major and trace element data for NIST SRM 610 and NIST SRM 612 glass reference materials. Geostand Newsl 21:115–144

    Google Scholar 

  • Perkins WG (1984) Mount Isa silica dolomite and copper orebodies; the result of a syntectonic hydrothermal alteration system. Econ Geol 79:601–637

    Google Scholar 

  • Perkins WG (1990) Mount Isa copper orebodies. In: Hughes FE (ed) Geology of the mineral deposits of Australia and Papua New Guinea. Australasian Institute of Mining and Metallurgy, pp 935–941

  • Perkins C, Heinrich CA, Wyborn LAI (1999) 40Ar/39Ar geochronology of copper mineralization and regional alteration, Mount Isa, Australia. Econ Geol 94:23–36

    Google Scholar 

  • Phillips GN, Evans KA (2004) Role of CO2 in the formation of gold deposits. Nature 429:860–863

    Article  Google Scholar 

  • Rubenach MJ (1992) Proterozoic low-pressure/high-temperature metamorphism and an anticlockwise P–T–t path for the Hazeldene area, Mount Isa Inlier, Queensland, Australia. J Metamorph Geol 10:333–346

    Google Scholar 

  • Schwartz MO, Akanyang P, Trippler K, Ngwisanyi TH (1995) The sediment-hosted Ngwako Pan Copper Deposit, Botswana. Econ Geol 90:1118–1147

    Google Scholar 

  • Shvarov Y, Bastrakov E (1999) HCh: a software package of geochemical equilibrium modelling. User’s guide. Australian Geological Survey Organisation, Canberra

    Google Scholar 

  • Smith SE, Walker KR (1971) Primary element dispersions associated with mineralization at Mount Isa, Queensland. Bulletin-Australia, Bureau of Mineral Resources, Geology and Geophysics 131

  • Swager CP (1985) Syndeformational carbonate-replacement model for the copper mineralization at Mount Isa, Northwest Queensland; a microstructural study. Econ Geol 80:107–125

    Google Scholar 

  • Valenta R (1994) Syntectonic discordant copper mineralization in the Hilton Mine, Mount Isa. Econ Geol 89:1031–1052

    Article  Google Scholar 

  • van Achterbergh E, Ryan CG, Jackson SE, Griffin WL (2001) Data reduction software for LA-ICP-MS. In: Sylvester P (ed) Laser ablation-ICPMS in the Earth Sciences. Mineral Association of Canada Short Course Handbook 29, pp 239–243

  • Waring CL (1990) The genesis of the Mount Isa copper orebodies. Ph.D. thesis, Monash University, Melbourne

  • Waring CL, Heinrich CA, Wall VJ (1998) Proterozoic metamorphic copper deposits. AGSO J Aust Geol Geophys 17:239–246

    Google Scholar 

  • Wilde AR, Gregory MJ, Duncan RJ, Gessner K, Kuhn M, Jones PA (2005) Geochemical process model for the Mt. Isa Cu–Co–Ag deposits. In: Mao J, Bierlein F (eds) Eight biennial SGA meeting–mineral deposit research: meeting the global challenge, Beijing, China, pp 199–202

  • Wilson IH, Derrick GM, Perkin DJ (1985) Eastern Creek Volcanics; their geochemistry and possible role in copper mineralisation at Mount Isa, Queensland. BMR J Aust Geol Geophys 9:317–328

    Google Scholar 

  • Wyborn LAI (1987) The petrology and geochemistry of alteration assemblages in the Eastern Creek Volcanics, as a guide to copper and uranium mobility associated with regional metamorphism and deformation, Mount Isa, Queensland. In: Pharaoh TC, Beckinsale RD, Rickard DT (eds) Geochemistry and mineralization of Proterozoic Volcanic Suites, Keyworth, United Kingdom, pp 425–434

Download references

Acknowledgements

The work reported in this study was conducted as part of the predictive mineral discovery Cooperative Research Centre, with support from Xstrata Copper, and this paper is published with the permission of the CEO. I wish to thank Andy Wilde, Lucy Chapman, David Cooke, Robert Duncan, Frank Bierlein, Geordie Mark, Mike Rubenach and two anonymous Mineralium Deposita reviewers for their many suggestions that led to significant improvements to this paper.

Author information

Authors and Affiliations

Authors

Corresponding author

Correspondence to Melissa J. Gregory.

Additional information

Editorial handling: B. Gemmell

Electronic supplementary material

Below is the link to the electronic supplementary material.

ESM 1 Appendix 1

(DOC 56 kb)

ESM 2 Appendix 2

(DOC 8 kb)

Rights and permissions

Reprints and permissions

About this article

Cite this article

Gregory, M.J. Copper mobility in the Eastern Creek Volcanics, Mount Isa, Australia: evidence from laser ablation ICP-MS of iron-titanium oxides. Miner Deposita 41, 691–711 (2006). https://doi.org/10.1007/s00126-006-0086-2

Download citation

  • Received:

  • Accepted:

  • Published:

  • Issue Date:

  • DOI: https://doi.org/10.1007/s00126-006-0086-2

Keywords

Navigation