Journal article

Geochronological constraints on the Tropicana gold deposit and Albany-Fraser orogen, Western Australia

MG Doyle, IR Fletcher, J Foster, RR Large, R Mathur, NJ McNaughton, S Meffre, JR Muhling, D Phillips, B Rasmussen

Economic Geology | Published : 2015

Abstract

Gold mineralization at the Tropicana mine occurs within the Plumridge terrane along the eastern margin of the Archean Yilgarn craton in the Albany-Fraser orogen, Western Australia. Mineralization is hosted in a favorable syenitic lithofacies of the Tropicana Gneiss with a minimum igneous age of 2638 ± 4 Ma (2σ) and which was metamorphosed to mid-amphibolite to lower granulite facies in the period ca. 2638 to 2520 Ma. The Tropicana Gneiss was exhumed to crustal levels equivalent to greenschist-facies conditions by the time of economic gold mineralization. The major gold-bearing pyrite-biotite-sericite mineralization formed in association with shear zones during northeast-southwest compression..

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University of Melbourne Researchers

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Funding Acknowledgements

This research was funded by Tropicana Joint Venture partners, Anglogold Ashanti Ltd., and Independence Group NL. AngloGold Ashanti and Independence Group are thanked for permission to publish the outputs of the research. SHRIMP and SEM facilities in Perth are supported by the John de Laeter Centre, a university-government consortium, and the Australian Research Council. The assistance of Stan Szczepanski, with the <SUP>40</SUP>Ar/<SUP>39</SUP>Ar analyses conducted at the University of Melbourne, is acknowledged, as are comments by Fred Jourdan. Matthew Grant is thanked for preparing biotite samples for analysis. MGD acknowledges the kind support provided by the Economic Geology Research Unit, James Cook University, through an adjunct appointment. Jochen Kolb and John Miller are thanked for helpful reviews which improved the paper.