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Gem-corundum megacrysts from east Australian basalt fields: trace elements, oxygen isotopes and origins


Sutherland, FL and Zaw, K and Meffre, SJM and Giuliani, G and Fallick, AE and Graham, IT and Webb, GB, Gem-corundum megacrysts from east Australian basalt fields: trace elements, oxygen isotopes and origins, Australian Journal of Earth Sciences, 56, (6) pp. 1003-1022. ISSN 0812-0099 (2009) [Refereed Article]

DOI: doi:10.1080/08120090903112109


Gem corundum, a minor but persistent megacryst in east Australian basalt fields, is mined from some placer concentrations. Laser ablation, inductively coupled plasma mass spectrometry analyses and O isotope determinations on a colour range of corundum from different fields, show that chromophore (Fe, Cr, Ti, V) and genetic indicator (Ga, Mg, 18O) values can distinguish corundum sources (magmatic, metamorphic and metasomatic) before basalt incorporation. They also characterise corundum groups from different fields. This identified two metamorphic groups, one carrying ruby at Barrington Tops, and a magmatic group distinct from those from other gem fields (lower Fe, northeast Tasmania; higher Fe, Yarrowitch). Ruby-bearing groups show clear provincial characteristics and include lower temperature spinel-facies groups (Barrington, Yarrowitch) and higher temperature garnet-facies groups (Cudgegong-Macquarie River). High Mg/Fe and Ni values in the latter approach those for corundum in diamond, and are a possible diamond indicator. The corundum derived from diverse fold-belt and felsic sources in underlying lithosphere forms a dataset for comparing corundum from other basalt fields.

Item Details

Item Type:Refereed Article
Keywords:gem corundum, Australia, La-ICPMS, oxygen isotopes
Research Division:Earth Sciences
Research Group:Geochemistry
Research Field:Geochemistry not elsewhere classified
Objective Division:Mineral Resources (Excl. Energy Resources)
Objective Group:Mineral exploration
Objective Field:Mineral exploration not elsewhere classified
UTAS Author:Zaw, K (Professor Khin Zaw)
UTAS Author:Meffre, SJM (Professor Sebastien Meffre)
ID Code:62035
Year Published:2009
Web of Science® Times Cited:58
Deposited By:Centre for Ore Deposit Research - CODES CoE
Deposited On:2010-03-09
Last Modified:2010-04-14

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