Geological and Atmospheric Sciences
Journal or Book Title
Application of Indicator Mineral Methods to Exploration
27th International Applied Geochemistry Symposium
April 20-24, 2015
Although the presence of indicator minerals has long been used as a guide in the exploration for various ore deposits on a regional scale (e.g. Spry 2000; McClenaghan 2005), the composition of these minerals has also helped to target sulphide mineralisation on a more local scale. Using major element compositions, an increase in the Mg/(Mg+Fe) ratio of ferromagnesian silicates, including garnet, biotite, tourmaline, chlorite, staurolite, cordierite, and amphibole, has been used to indicate proximity to metamorphosed ore deposits in low- to highgrade metamorphic terranes (e.g. Nesbitt 1986; Bryndzia & Scott 1987). More recently, trace element studies using various techniques (e.g. electron microprobe, laser ablation-inductively coupled plasma-mass spectrometry (LA-ICP-MS), protoninduced X-ray emission (PIXE)) have allowed the provenance of minerals and their composition in various ore deposits to be determined. Such techniques facilitate the measurement of many elements at concentrations as low as parts per billion (e.g. Jackson, 1992). Trace element studies of minerals spatially related to metallic mineral deposits include titanite in porphyry Cu deposits (Xu et al. 2014), magnetite in porphyry Cu-Mo, orogenic Au, skarn, iron oxide-copper-gold (IOCG), volcanogenic massive sulphide (VMS), and Ni-Cu-platinum-group element deposits (e.g. Dupuis & Beaudoin 2011; Nadoll et al. 2012, 2014), maghemite and hematite in IOCG deposits (e.g. Schmidt Mumm et al. 2012), garnet in skarn (e.g. Gaspar et al. 2008) and Broken Hill-type (BHT) deposits (Spry et al. 2007), and chromite (e.g. Pagé & Barnes 2009), and ilmenite (e.g. Dare et al. 2012) in magmatic sulphide deposits. Nine minerals (feldspar, calcite, garnet, pyroxene, amphibole, allanite, epidote- group minerals, titanite, and apatite) were analyzed by Ismail et al. (2014) in a study of the Hillside IOCG deposit, South Australia.
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Spry, Paul G.; O’Brien, J. J.; Frank, K. S.; Teale, G. S.; Koenig, A.; Jansson, N.; Allen, R.; and Raat, H., "Trace element compositions of silicates and oxides as exploration guides to metamorphosed massive sulphide deposits: examples from Broken Hill, Australia, and Stollberg, Sweden" (2015). Geological and Atmospheric Sciences Conference Presentations, Posters and Proceedings. 10.