The Origin of HIMU in the SW Pacific: Evidence from Intraplate Volcanism in Southern New Zealand and Subantarctic Islands

• Main Authors: K. S. Panter, J. Blusztajn, S. R. Hart, P. R. Kyle, R. Esser, W. C. Mcintosh
• Other Authors: The Pennsylvania State University CiteSeerX Archives
• Format: Text
• Language: English
• Published: 2005
• Subjects: West Antarc; West Antarctica; Pacific; New Zealand; Campbell Island; Antarc*; Antarctica
• Online Access: http://citeseerx.ist.psu.edu/viewdoc/summary?doi=10.1.1.598.3679; http://petrology.oxfordjournals.org/content/47/9/1673.full.pdf

This paper presents field, geochemical and isotopic (Sr, Nd, Pb) results on basalts from the Antipodes, Campbell and Chatham Islands, New Zealand. New 40Ar/39Ar age determinations along with previous K–Ar dates reveal three major episodes of volcanic activity on Chatham Island (85–82, 41–35, 5 Ma). Chatham and Antipodes samples comprise basanite, alkali and transitional basalts that have HIMU-like isotopic (206Pb/204Pb> 203–208, 87Sr/86Sr <07033, 143Nd/144Nd>05128) and trace element affinities (Ce/Pb 28–36, Nb/U 34–66, Ba/Nb 4–7). The geochemistry of transitional to Q-normative samples from Campbell Island is explained by interaction with continental crust. The volcanism is part of a long-lived (100Myr), low-volume, diffuse alkaline magmatic province that includes deposits on the North and South Islands of New Zealand as well as portions of West Antarctica and SE Australia. All of