Sulfur isotope data are available for 18 low-sulfide orogenic gold systems hosted by the Lachlan Orogen in eastern New South Wales including those in the northern Hill End Trough (Hargraves, Hill End, Napoleon Reefs, Sofala-Wattle Flat, Stuart Town, Windeyer) and adjacent areas (Bodangora, Lucknow, Springfield), the Gilmore Fault Zone (Adelong, Sebastopol) and those in the Parkes district (Calarie, London-Victoria, Wyoming One-Myall United). Other systems for which data are available include Mongarlowe, Murrumbateman, McMahons Reef and Yalgogrin._x000D_
The d34S data for many of the larger deposits including Adelong, Bodangora, Calarie, Hargraves, Hill End London-Victoria, Lucknow, Sebastopol, Sofala-Wattle Flat, Stuart Town and Windeyer (Group 1) are all very similar and have average d34S values close to zero per mil. Near 0 d34S signatures imply that sulfur was sourced from a magmatic reservoir. Furthermore, the large Wyoming One deposit has d34S values significantly below 0 with the data implying that sulfur was sourced from a fractionated magmatic reservoir._x000D_
Group 2 deposits include those at Mongarlowe, Murrumbateman, Napoleon Reefs, McMahons Reef and Springfield . These deposits have average d34S values significantly above 0. With the exception of Springfield where sulfur was probably sourced from the Hill End Trough, Group 2 deposits are an order of magnitude smaller than Group 1 deposits._x000D_
The results suggest that many of the larger orogenic-related gold deposits hosted by the Lachlan Orogen in eastern New South Wales derived sulfur and gold as a result of leaching and recycling from a magmatic reservoir. Alternatively, there may have been direct mantle-derived input; however, this is considered unlikely on geological grounds._x000D_
AnEXTENDED ABSTRACTis available for download. A full-length paper was notprepared for this presentation.