Crustal-scale controls on zinc-lead-silver deposits of the North Australian Zinc Belt: evidence from lead isotope geochemistry and surface wave tomography

Abstract

The North Australian Zinc Belt is the largest Zn-Pb province in the world, containing three of the ten largest individual deposits known. Despite this pedigree, exploration in this province over the last two decades has not been particularly successful, yielding only one significant deposit (Teena). One of the most important aspects of exploration is to choose regions or provinces that have greatest potential for discovery. New results from the North Australian Zinc Belt highlight previously unused datasets that may assist area selection and targeting at the craton- to district-scale.

Lead isotope mapping in the North Australian Zinc Belt using analyses of mineralized material has identified a gradient in mu (U-238/Pb-204) that coincides closely with many major deposits. Similarly, the locations of these deposits also coincide with gradient in the depth of the lithosphere-asthenosphere boundary as determined from surface wave tomography. The change from thicker to thinner lithosphere is interpreted to localize prospective basins for Zn-Pb and Cu-Co mineralization, a change that is also thought to control the gradient in lead isotope data. Keywords