40Ar/39Ar geochronology of the Tara intrusion-related base metal deposit: implications for metallogenesis in the central Lachlan Orogen
Dating of eight muscovite grains from a quartz–muscovite–sulfide vein from the Tara intrusion-related base metal system 20 km east-northeast of Hillston, New South Wales, yielded indistinguishable 40Ar/39Ar age results with a weighted mean age of 420 ± 2 Ma. The deposit is hosted by a metamorphosed turbidite sequence that includes medium- to thin-bedded quartz sandstone, shale, siltstone and mudstone. A Late Silurian age for the mineralisation at Tara extends the spatial distribution of intrusion-related mineral systems of similar age within the Central Subprovince of the Lachlan Orogen. Tara formed at approximately the same time as the Mineral Hill (Ag–Pb–Zn and Cu–Au) and Holbrook (Mo) intrusion-related mineral systems and the initial magmatic event associated with the Ardlethan tin deposit. The recognition that Tara is part of a widespread Late Silurian metallogenic and thermal event increases the prospectivity of the Cargelligo 1:250 000 map sheet area.
| Download |
|---|
