Lithogeochemistry, C-O isotopes and Stratabound Alteration Halos to Stratiform Copper Mineralisation, Zambian Copperbelt

Large Ross; McGoldrick Peter; Bull Stuart; Scott Robert; Selley David; Croaker Mawson; Pollington Nicole

doi:10.1071/ASEG2006ab092

ISSN: 2202-0586
E-ISSN:

oa Lithogeochemistry, C-O isotopes and Stratabound Alteration Halos to Stratiform Copper Mineralisation, Zambian Copperbelt
Authors Large Ross^a, McGoldrick Peter^b, Bull Stuart^c, Scott Robert^d, Selley David^e, Croaker Mawson^f and Pollington Nicole^g
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^a CODESUniversity of Tasmania, Private Bag 79, Hobart, Tasmania, Australia, [email protected] ^b CODESUniversity of Tasmania, Private Bag 79, Hobart, Tasmania, Australia, [email protected] ^c CODESUniversity of Tasmania, Private Bag 79, Hobart, Tasmania, Australia, S. [email protected] ^d CODESUniversity of Tasmania, Private Bag 79, Hobart, Tasmania, Australia, [email protected] ^e CODESUniversity of Tasmania, Private Bag 79, Hobart, Tasmania, Australia, [email protected] ^f CODESUniversity of Tasmania, Private Bag 79, Hobart, Tasmania, Australia, [email protected] ^g CODESUniversity of Tasmania, Private Bag 79, Hobart, Tasmania, Australia, [email protected]
Publisher: Australian Society of Exploration Geophysicists
Source: ASEG Extended Abstracts, Volume 2006, Issue ASEG2006 - 18th Geophysical Conference, Dec 2006, p. 1 - 7
DOI: https://doi.org/10.1071/ASEG2006ab092
- Published online: 01 Dec 2006

Abstract

A major lithogeochemical study of the basin sediments surrounding the stratiform copper deposits of the Zambian Copper Belt has revealed extensive stratabound zones of both potassio and sodic alteration. The syn-ore potassio alteration is represented by enrichment of biotite and K-feldspar in the enclosing sediments, with whole rock K20 values varying from 3.5 to 10 wt%. The sodic alteration (albite-calcite), post-dates the copper mineralisation, and occurs in the Upper Roan siltstone-carbonate sequence overlying the potassio alteration zone. Na20 values vary from 1.5 to 6.3 wt%, corresponding to a maximum of 60 wt% albite in the altered rock.

A comprehensive study of carbon and oxygen isotopes of various carbonate types throughout the sediments of the Zambian Copper Belt has shown a systematic relationship to alteration and copper mineralisation that has significant application in mineral exploration. Mineralised and potassically altered zones show strong coupled depletion in both carbon and oxygen isotopes, with δ¹³C = -6 to –26 per mil and δ ¹⁸O = 6 to 20 per mil. The strongly negative δ ¹³C values of carbonate in the ore shale and potassio footwall elastics indicates the significant role of oxidation of organic carbon in the mineralising process. The fact that the relatively clean altered and mineralised footwall elastics also show this negative carbon isotope shift suggests that organic reaction products migrated out of the shale into the permeable footwall elastics prior to mixing with the ore fluid, leading to redox reactions causing coupled oxidation of organic matter and reduction of sulfate to H2S resulting in copper sulfide precipitation.

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References

Annels, A.E., 1989, Ore genesis in the Zambian Copperbelt, with particular reference to the northern sector of the Chambishi Basin: Geological Association of Canada Special Paper, vol. 36, p. 427-452.
Cunningham, M.J., 1986, Copper-cobalt mineralization in the northern portion of the Chambishi Basin, Zambia, unpublished PhD research report, University College, Cardiff.
Darnley, A. G., 1960, Petrology of some Rhodesian Copperbelt Orebodies and associated rocks: Trans. Inst. Min. Metall., v. 69, p. 137-173.
Derry, L.A., Kaufman, A.J., and Jacobsen, S.B., 1992, Sedimentary cycling in the Late Proterozoic: Evidence from stable and radiogenic isotopes: Geochem. Cosmochim. Acta, 56, p. 173-198.
Frimmel, H.E., Foiling, P.G., and Eriksson, P.G., 2002, Neoproterozoic tectonic and climatic evolution recorded in the Gariep Belt, Namibia and South Africa: Basin Research, vol. 14, p. 55-67.
Herrmann, W., and Berry, R. F., 2002, MINSQ ’ a least squares spreadsheet method for calculating mineral proportions from whole rock major element analyses: Geochemistry; Exploration, Environment, Analysis, v.2, p.361-368.
Hitzman, M.W., and Beaty, D.W., 1996, The Irish Zn-Pb-(Ba) Orefield, in Sangster, D.F., ed., Carbonate-Hosted Lead-Zinc Deposits: Society of Economic Geologists Special Publication 4, p. 112-143.
Jacobsen, S.B., and Kaufman, A.J., 1999, The Sr, C and O isotopie evolution of Neoproterozoic seawater: Chem. Geology, 161, p. 37-57.
Land, L.S., 1983, The application of stable isotopes to studies of the origin of dolomite and to problems of diagenesis of clastic sediments: Society of Economic Palaeontologists and Mineralogists Short Course 10, p. 4, 1-4:22.
Large, R. R., McGoldrick, P. J., Bull, S. W., Scott, R., and Selley, D., (this volume), Lithogeochemistry and Alteration Halos to Stratiform Copper Mineralisation in the Chambishi Basin, Zambian Copper Belt: AMIRA PS444, Final Report, October, 2003.
Large, R.R., Bull, S.W., and Winefield, P.P., 2001, Carbon and Oxygen Isotope Halo in Carbonates Related to the McArthur River (HYC) Zn-Pb-Ag Deposit, North Australia: Implications for Sedimentation, Ore Genesis, and Mineral Exploration: Economic Geology, v. 96, p. 1567-1593.
McCrea, L.M., 1958, The isotope chemistry of carbonatates and a paleotemperature scale: Journal of Chemistry Physics, v. 18, p. 849-857.
Moine, B., Guilloux, L., and Audeoud, D., 1986, Major element geochemistry of the host rocks in some sediment-hosted copper deposits; in Friedrich, G. H. (ed.) Geology and Metallogeny of Copper Deposits, Springer-Verlag, Berlin, 1986, p. 443-60.
Ohmoto, H., and Rye, R.O., 1979, Isotopes of Sulfur and Carbon, in Barnes, H.L., ed., Geochemistry of Hydrothermal Order Deposits – third edition: New York, Wiley, p. 509-567.
Ohmoto, H., and Goldhaber, M.B., 1997, Sulfur and carbon isotopes, in Barnes, H.L., ed., Geochemistry of Hydrothermal Order Deposits – third edition: New York, Wiley, p. 517-612.
Rollinson, H., 1993, Using Geochemical Data: Evaluation, Presentation and Interpretation: Longman, Essex, 352pp.
Schwarcz, H.P., Clayton, R.N., and Mayeda, T., 1970, Oxygen isotopie studies of calcareous and pelitic metamorphic rocks, New England: Geological Society of America Bulletin, vol. 81, no. 8, p. 2299-2315.
Sweeney, M. A., and Binda, P. L., 1989, The role of diagenesis in the formation of the Konkola Cu-Co orebody of the Zambian Copper Belt: Geological Association of Canada Special Paper, vol. 36, p. 499-518.
Taylor, B.E., 1987, Stable isotope geochemistry of ore-forming fluids, in Keyser, T.K., ed., Short Course in Stable Isotope Geochemistry of Low Temperature Fluids: Mineral Association Canada., v. 13, p. 337-445.
Valley, J.W., 1986, Stable isotope geochemistry of metamorphic rocks, in Valley, J.W., Taylor, H.P., and O’neil, J.R, eds., Stable Isotopes in High Temperature Geological Processes: Mineral Association of America Reviews in Mineralogy, v. 16, p. 445-490.
Viezer, J., 1983, Chemical diagenesis of carbonates: theory and application of trace element technique: Society of Economic Palaeontologists and Mineralogist Short Course 10, p. 3-1-3-100.
Wilson, N. S. F., Zentilli, M., Spiro, B., 2003, A sulfur, carbon, oxygen and strontium isotope study of the volcanic-hosted El Soldado manto-type copper deposit, Chile: the essential role of bacteria and petroleum: Economic Geology, v. 98, p. 163-174.

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Article Type: Research Article

Keyword(s): Carbon Isotopes; Lithogeochemistry; Stratiform Copper; Zambian Copper Belt.

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oa Lithogeochemistry, C-O isotopes and Stratabound Alteration Halos to Stratiform Copper Mineralisation, Zambian Copperbelt

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