Australian Zn-Pb-Ag Deposits: A basin system and fluid flow analysis - Economic Geology special volume

Paleoproterozoic rocks of northern Australia host one of the world's largest base metal repositories and are the world's most important zinc repository. The McArthur-Mount Isa-Cloncurry mineral belt contains several world-class Zn-Pb-Ag, U, Cu, and Cu-Au deposits (Ewers and Fergusson, 1980; Williams, 1998; Betts et al., 2003; Large et al., 2005; Fig. 1). The province has the potential to host additional base metal and uranium reserves. Advances in exploration techniques in the 1980s led to the discovery of several major new Zn and Cu-Au deposits, including Cannington, Century, Ernest Henry, and Osborne. However, recent exploration results have been disappointing and new exploration strategies are required if the region is to further its growth potential and if new resources are to be realized beneath shallow cover. Between 1975 to 1995 geoscientists from Geoscience Australia, the Geological Survey of Queensland, and the Northern Territory Geological Survey mapped the Paleoproterozoic outcrop belt of northern Australia at a scale of 1:100,000. Subsequently, researchers at Monash University undertook detailed studies of the deformation history of the Mount Isa block, placing the ore deposits within a tectonic context (e.g., O'Dea et al., 1997; Betts et al., 1998, 2003; Betts and Lister, 2002). Researchers at James Cook University carried out structural, metamorphic and mineralization studies across the Mount Isa block, with their principal focus concentrating on the deposits and their immediate environs (Bell et al., 1988; Broadbent et al., 1998; Williams, 1998). Between 1990 and 1998 a multidisciplinary research group based at CODES, University of Tasmania, completed studies aimed at better understanding the origin of the region's zinc deposits and their alteration halos in both the McArthur and Mount Isa regions (Cooke et al., 1998, 2000; Large et al., 1998, 2000, 2005; Garven et al., 2001; Yang et al., 2004). Each of the studies outlined above were based on lithostratigraphic concepts in which rock units were subdivided, mapped, and labeled, but the units defined are diachronous and cannot be used for reconstructions of basin shape and sediment architecture at the times of fluid migration. This requires an event-based chronostratigraphic framework.