The geochemistry and petrogenesis of Carnley Volcano, Auckland Islands, SW Pacific

• Main Authors: Gamble, John A., Adams, Chris J., Morris, Paul A., Wysoczanski, Richard J., Handler, Monica, Timm, Christian
• Format: Dataset
• Language: unknown
• Published: Taylor & Francis 2018
• Subjects: Physiology; FOS Biological sciences; Biotechnology; Evolutionary Biology; Geology; FOS Earth and related environmental sciences; 39999 Chemical Sciences not elsewhere classified; FOS Chemical sciences; Ecology; 20199 Astronomical and Space Sciences not elsewhere classified; FOS Physical sciences; Marine Biology; Inorganic Chemistry; 110309 Infectious Diseases; FOS Health sciences; Byrd; Marie Byrd Land; Pacific; Ross Sea; Antarc*; Antarctica; Auckland Islands; Ocean Island
• Online Access: https://dx.doi.org/10.6084/m9.figshare.7108760.v1; https://tandf.figshare.com/articles/The_geochemistry_and_petrogenesis_of_Carnley_Volcano_Auckland_Islands_SW_Pacific/7108760/1

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 206 Pb/ 204 Pb (18.9–22.5), 87 Sr/ 86 Sr = ∼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.