Quick Search:    advanced search

GSW Home   GeoRef Home   My GSW Alerts   Contact GSW   About GSW   Journals List   Help

This Article Figures Only Full Text Full Text (PDF) Alert me when this article is cited Alert me if a correction is posted Citation Map Services Email this article to a friend Similar articles in this journal Similar articles in Web of Science Alert me to new issues of the journal Download to citation manager Citing Articles Citing Articles via HighWire Citing Articles via Google Scholar Google Scholar Articles by Anderson, B. R. Articles by Nelson, D. R. Search for Related Content GeoRef GeoRef Citation

LEAD ISOTOPE EVOLUTION OF MINERAL DEPOSITS IN THE PROTEROZOIC THROSSELL GROUP, WESTERN AUSTRALIA

Bruce R. Anderson^,* and J. Bruce Gemmell

Centre for Ore Deposit Research, University of Tasmania, Hobart, Tasmania 7001, Australia

David R. Nelson

Geological Survey of Western Australia, 100 Plain Street, Perth, Western Australia

Corresponding author: email, bruce_anderson{at}moh.govt.nz

The Meso-Neoproterozoic Throssell Group of the Paterson orogen in Western Australia hosts the Nifty and Maroochydore sediment-hosted, replacement Cu deposits, as well as subeconomic Pb-Cu-Au veins at Goosewacker, carbonate-hosted Zn-Pb at Warrabarty, and pyritic massive sulfide at Grevillea. We report new Pb isotope data for the Nifty deposit and the Rainbow and Grevillea prospects. These data are combined with published and unpublished data to characterize the Pb isotope signatures of the deposits and prospects in the Throssell Group. In addition these data are integrated into a model for the sources of Pb in the mineralizing systems.

Lead isotope data from mineralized occurrences in the Throssell Group plot as a linear trend in ²⁰⁷Pb/²⁰⁴Pb-²⁰⁶Pb/²⁰⁴Pb space. Deposits and prospects are arranged, from least to most radiogenic, as Rainbow, Warrabarty, Nifty, Goosewacker, and Maroochydore, along the trend. Secondary isochron or mixing isochron models were previously proposed to interpret the Pb isotope trend for mineral deposits and prospects in the Throssell Group. Our investigation shows that the linear trend does not represent an isochron due to the syngenetic (pre-D₄) timing for mineralization at Warrabarty and Rainbow compared to an epigenetic (syn-D₄) timing for Maroochydore, Nifty, and Goosewacker. We propose a source-mixing model, with no time dependency, to explain the deposit Pb isotope linear trend where Pb from a primitive, mantle source (Pilbara Craton, µ = 9.88) is mixed with crustal Pb (Throssell Group sedimentary rock derived from the Rudall Complex, µ = 10.55). The position of deposits and prospects along the trend suggests that the Warrabarty and Rainbow prospects have more primitive Pb and that the Maroochydore deposit contains Pb from primarily a crustal source. The Nifty deposit, and the Goosewacker and Grevillea prospects, contain a mixture of both primitive and crustal Pb.

This article has been cited by other articles:

				S. E. Kesler and M. H. Reich Precambrian Mississippi Valley-type deposits: Relation to changes in composition of the hydrosphere and atmosphere Geological Society of America Memoirs, January 1, 2006; 198(0): 185 - 204. [Abstract] [Full Text] [PDF]