Base metal exploration of the mount read volcanics, Western Tasmania: PT. II. lead isotope signatures and genetic implications.

Lead isotope measurements of 13 deposits and prospects from western Tasmania have been undertaken to establish a framework for the use of the lead isotope technique in exploration and to gain an understanding of the processes of ore formation. Lead isotope signatures for the Cambrian volcanogenic deposits (Mount Lyell, Rosebery, Hercules, Que River, Hellyer) differ by more than 1 percent from those characterizing the post-Cambrian mineralization, thought to be related to Devonian-Carboniferous ganitoids and/or Tabberabberan metamorphism (e. g. , Renison Bell, Queen Hill, Spray mine, Farrell lodes). The differences in lead isotope signatures allow discrimination of the two contrasting styles of mineralization in both surface material and drill core; the isotopic signatures have been utilized in an exploration program at Elliott Bay which is described in companion papers.