The geochemistry and petrogenesis of Carnley Volcano, Auckland Islands, SW Pacific
Gamble, John A.; Adams, Chris J.; Morris, Paul A.; Wysoczanski, Richard J.; Handler, Monica; Timm, Christian
Date:
2018-09-19
Copyright:
© 2018, Informa UK Limited, trading as Taylor & Francis Group. This is an Accepted Manuscript of an article published by Taylor & Francis in New Zealand Journal of Geology and Geophysics on 19 September, 2018, available online: http://www.tandfonline.com/10.1080/00288306.2018.1505642
Full text restriction information:
Access to this article is restricted until 12 months after publication by request of the publisher.
Restriction lift date:
2019-09-19
Citation:
Gamble, J. A., Adams, C. J., Morris, P. A., Wysoczanski, R. J., Handler, M. and Timm, C. (2018) 'The geochemistry and petrogenesis of Carnley Volcano, Auckland Islands, SW Pacific', New Zealand Journal of Geology and Geophysics, 61(4), pp. 480-497. doi:10.1080/00288306.2018.1505642
Abstract:
Intraplate volcanism across Zealandia, South Eastern Australia, the Ross Sea Embayment and Marie Byrd Land in Antarctica define a magmatic province characterised by basalts with elevated 206Pb/204Pb (18.9–22.5), 87Sr/86Sr = ∼0.7035, Light Rare Earth enrichment [(Ce/Yb)n > 10], and convex-up mantle normalised incompatible multi-element patterns, peaking at Nb-Ta, with negative K and Pb anomalies. Trace element abundances and ratios (e.g. Zr/Nb, Y/Zr) resemble Ocean Island Basalts (OIB), distinct from Mid-Ocean Ridge Basalt (MORB), suggesting derivation from OIB-like reservoirs. Our preferred scenario envisages partial melting across the garnet-spinel stability fields involving asthenospheric and lithospheric mantle components. Melts accumulate in a column where the deep (asthenospheric) source is PM and the shallower source a melange of PM and subcontinental lithospheric mantle (DMM+1) enriched by carbonatite. Evolution of primary and near-primary magmas is controlled by olivine + clinopyroxene fractionation. Trachybasalts, trachytes and rhyolites show isotopic evidence for interaction with continental crust.
Show full item record
