https://ogma.newcastle.edu.au/vital/access/ /manager/Index en-au 5 Sulfur- and lead-isotope signatures of selected middle Silurian to Carboniferous mineral systems of the Lachlan Orogen, eastern New South Wales - implications for metallogenesis https://ogma.newcastle.edu.au/vital/access/ /manager/Repository/uon:7940 Wed 11 Apr 2018 16:21:02 AEST ]]> Sulfur isotope and fluid inclusion geochemistry of metamorphic Cu-Au vein deposits, central Cobar area, NSW, Australia https://ogma.newcastle.edu.au/vital/access/ /manager/Repository/uon:34678 34S values from 3.8 to 11.2‰ (average 7.9‰) is present. Sulfur is likely to have been derived from rock sulfur/sulfide in basin and basement rocks, but there may be an additional connate-derived component. Homogenisation temperatures (Th) for inclusion fluids trapped in quartz and minor calcite veins range from near 150°C to 397°C. Fluid inclusions are characterised by a low CO₂ content and low, but variable salinities (2.1–9.1 wt% NaCl equivalent). Generations of inclusion fluids correspond to six paragenetic stages of vein quartz deposition and recrystallisation at the Chesney mine. Primary fluid inclusions in the first two stages were subjected to re-equilibration resulting from increased confining pressure. Their Th range (151–317°C) is considered a minimum for the temperature of these fluids. Sulfide and gold deposition at Chesney appears to be related to fluids of moderately high Th (range 270–397°C) associated with the final paragenetic stage. Th for the ore-related fluids may be close to the solvus of the H₂O–NaCl–CO₂ system and hence near trapping temperatures. Late-stage entry of a hot, moderately saline ore-forming fluid is implicated as the origin of the Cu–Au mineralisation. However, comparison with geochemical data for the vein-style Zn–Pb–Ag deposits at Cobar demonstrates that differences in metal content for individual zones cannot be attributed to major differences in fluid temperature or salinity. Rather, these differences are probably due to variations in source-rock reservoirs and structural pathways along which the ore-forming fluids moved.]]> Thu 11 Apr 2019 15:08:51 AEST ]]> Yerranderie a Late Devonian silver-gold-lead intermediate sulfidation epithermal district, eastern Lachlan Orogen, New South Wales, Australia https://ogma.newcastle.edu.au/vital/access/ /manager/Repository/uon:3193 Sat 24 Mar 2018 07:21:55 AEDT ]]> Sulfur isotope distribution in Late Silurian volcanic-hosted massive sulfide deposits of the Hill End Trough, eastern Lachlan Fold Belt, New South Wales https://ogma.newcastle.edu.au/vital/access/ /manager/Repository/uon:3416 Sat 24 Mar 2018 07:21:38 AEDT ]]>