Evidence for a mafic connection to the roots of caldera-related epithermal vein mineralization in north Queensland
Baker, T., Johnson, D., Snook, P., Bishop, A., Richmond, J., and Woodman, P. (2009) Evidence for a mafic connection to the roots of caldera-related epithermal vein mineralization in north Queensland. In: Proceedings of the 10th Biennial Meeting of the the SGA 2009 (1), pp. 515-517. From: 10th Biennial Meeting of the SGA 2009, 17-20 August 2009, Townsville, QLD, Australia.
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North Queensland contains numerous, large Carboniferous to Permian caldera complexes that are associated with economically significant magmatichydrothermal mineralisation. The recently discovered Piccaninny Epithermal System (PES), 200km west of Cairns, occurs on the southeastern margin of the poorly exposed North Scardons Igneous Complex which is interpreted to be a large caldera (~300 km2). The roots of the epithermal system are exposed in the Proterozoic McDevitt Metamorphics and the veins are characterised by dominantly comb to locally banded crustiformcolloform quartz that host Ag-Pb-Zn-Au-As mineralisation. The vein array is spatially associated with basalt dykes that have exploited caldera-rim parallel NESW faults, and E-W and NW-SE structures. The PES lies on a gravity gradient defined by a gravity high related to the basalt dykes and buried mafic intrusions and gravity lows related to the caldera and felsic intrusions. A basaltic magma emplaced into the upper crust may have been responsible for crustal melting that produced felsic rocks associated with the caldera. Furthermore, the strong spatial and temporal association of basalt dykes and veins may also suggest a mafic source for metals and sulphur in the PES.
|Item Type:||Conference Item (Abstract / Summary)|
|Keywords:||North Queensland; caldera; basalt; epithermal deposits|
Conference theme "Smart Science for Exploration and Mining"
|Date Deposited:||10 Sep 2010 01:09|
|FoR Codes:||04 EARTH SCIENCES > 0403 Geology > 040307 Ore Deposit Petrology @ 100%|
|SEO Codes:||84 MINERAL RESOURCES (excl. Energy Resources) > 8401 Mineral Exploration > 840105 Precious (Noble) Metal Ore Exploration @ 100%|