eCite Digital Repository

Geology and mineralogical zonation of the Olympic Dam Iron Oxide Cu-U-Au-Ag deposit, South Australia

Citation

Ehrig, K and McPhie, J and Kamenetsky, VS, Geology and mineralogical zonation of the Olympic Dam Iron Oxide Cu-U-Au-Ag deposit, South Australia, Geology and Genesis of Major Copper Deposits and Districts of the World: A Tribute to Richard H. Sillitoe, Society of Economic Geologists, Inc., Hedenquist, J.W., Harris, M., Camus, F. (ed), Littleton, CO, pp. 237-267. ISBN 978-1-934969-45-8 (2012) [Research Book Chapter]

Copyright Statement

Copyright 2012 Society of Economic Geologists, Inc.

Official URL: http://www.segweb.org/

Abstract

Olympic Dam is a supergiant Fe oxide Cu-U-Au-Ag deposit that is also strongly enriched in a wide range of elements, including F, S, C, As, Ba, Bi, Cd, Co, Cr, Fe, In, Mo, Nb, Ni, P, Pb, Sb, Se, Sn, Sr, Te, V, W, Y, Zn, and rare earth elements (REE). The deposit contains more than 90 minerals. Mineralization was associated with intense, texturally destructive hematite and sericite alteration and brecciation of the primary host rock units, including Roxby Downs Granite, bedded clastic facies rocks, and mafic-ultramafic dikes. Based on comprehensive geological, geochemical, and mineralogical data sets collected during a deposit-scale resource delineation and sterilization drilling program (2003C2008), compiled with historical geological data and interpretations, we quantify geochemical and mineralogical associations and distribution patterns.

The granite-derived elements (Al, Be, Ca, Hf, K, Li, Mg, Mn, Na, Rb, Si, Th, Ti, and Zr) are negatively correlated with Fe, whereas the hydrothermal elements (Ag, As, Au, Ba, Bi, Cd, Co, CO2, Cr, Cu, F, Fe, In, Mo, Nb, Ni, P, Pb, S, Sb, Se, Sn, Sr, Te, U, V, W, Y, Zn, and REE) are positively correlated; the ore and gangue minerals are also correlated with Fe abundance. There is a strong spatial association of Cu, U3O8, Au, and Ag. From the periphery inward and upward from depth toward the deposit center, the most significant zones are as follows: (1) reduced Fe oxide alteration (magnetite-apatite-siderite-chlorite-quartz) oxidized Fe oxide alteration (hematite-sericite-fluorite) hematite-quartz-barite alteration, (2) siderite fluorite barite, (3) sphalerite galena pyrite chalcopyrite bornite chalcocite nonsulfide, and (4) distal or paragenetically early (?) base metal-poor (Mo-W-Sn-As-Sb) base metal-rich (Cu-Pb-Zn) minerals sulfide-barren hematite-quartz-barite breccia in the deposit center. Spatially isolated remnants of advanced argillic alteration (sericite + quartz Al-OH) have been defined for the first time. Progressive Fe oxide addition to, and sericite replacement of the primary host rocks produced distinctive, albeit complex, hydrothermally altered and mineralized zones in the Olympic Dam deposit.

Item Details

Item Type:Research Book Chapter
Research Division:Earth Sciences
Research Group:Geochemistry
Research Field:Exploration Geochemistry
Objective Division:Mineral Resources (excl. Energy Resources)
Objective Group:Other Mineral Resources (excl. Energy Resources)
Objective Field:Mineral Resources (excl. Energy Resources) not elsewhere classified
Author:McPhie, J (Professor Jocelyn McPhie)
Author:Kamenetsky, VS (Professor Vadim Kamenetsky)
ID Code:86528
Year Published:2012
Deposited By:Centre for Ore Deposit Research - CODES CoE
Deposited On:2013-09-20
Last Modified:2017-11-02
Downloads:5 View Download Statistics

Repository Staff Only: item control page