Timing of shoshonitic magmatism and gold mineralization, Sheahan‐Grants and Glendale, New South Wales

Abstract
Isotopic 40Ar/39Ar, K‐Ar and U‐Pb dating of magmatic minerals from shoshonitic rocks in the Sheahan‐Grants/Glendale area, Lachlan Fold Belt, New South Wales, indicates a continuum of magmatic events in the area from approximately 480 to 430 Ma ago. The 40Ar/39Ar dating of hydrothermal sericite from the Glendale monzonite‐hosted gold deposit illustrates that mineralization was essentially contemporaneous with host magmatism at about 440 Ma, and that the Sheahan‐Grants skarn gold deposit may have formed at approximately the same time. The age of mineralization in these two systems is similar to that of other gold (and copper) deposits in the Lachlan Fold Belt.