title: Subduction of the oceanic Hikurangi Plateau and its impact on the Kermadec arc.
abstract: Large igneous province subduction is a rare process on Earth. A modern example is the subduction of the oceanic Hikurangi Plateau beneath the southern Kermadec arc, offshore New Zealand. This segment of the arc has the largest total lava volume erupted and the highest volcano density of the entire Kermadec arc. Here we show that Kermadec arc lavas south of ~32°S have elevated Pb and Sr and low Nd isotope ratios, which argues, together with increasing seafloor depth, forearc retreat and crustal thinning, for initial Hikurangi Plateau-Kermadec arc collision ~250 km north of its present position. The combined data set indicates that a much larger portion of the Hikurangi Plateau (the missing Ontong Java Nui piece) than previously believed has already been subducted. Oblique plate convergence caused southward migration of the thickened and buoyant oceanic plateau crust, creating a buoyant 'Hikurangi' mélange beneath the Moho that interacts with ascending arc melts.
authors.affiliation: GNS Science, PO Box 30-368, Lower Hutt 5040, New Zealand.
authors.forename: Christian
authors.initials: C
authors.lastname: Timm
authors.affiliation: GNS Science, PO Box 30-368, Lower Hutt 5040, New Zealand.
authors.forename: Bryan
authors.initials: B
authors.lastname: Davy
authors.affiliation: Geozentrum Nordbayern, Universität Erlangen-Nürnberg, Schlossgarten 5, 91054 Erlangen, Germany.
authors.forename: Karsten
authors.initials: K
authors.lastname: Haase
authors.affiliation: GEOMAR Helmholtz Centre for Ocean Research, FB4, Wischhofstrasse 1-3, 24148 Kiel, Germany.
authors.forename: Kaj A
authors.initials: KA
authors.lastname: Hoernle
authors.affiliation: GNS Science, PO Box 30-368, Lower Hutt 5040, New Zealand.
authors.forename: Ian J
authors.initials: IJ
authors.lastname: Graham
authors.affiliation: GNS Science, PO Box 30-368, Lower Hutt 5040, New Zealand.
authors.forename: Cornel E J
authors.initials: CE
authors.lastname: de Ronde
authors.affiliation: School of Earth Sciences, University of Melbourne, Parkville, Victoria 3010, Australia.
authors.forename: Jon
authors.initials: J
authors.lastname: Woodhead
authors.affiliation: Department of Earth Sciences, University of Oxford, Oxford OX1 3AN, UK.
authors.forename: Dan
authors.initials: D
authors.lastname: Bassett
authors.affiliation: GEOMAR Helmholtz Centre for Ocean Research, FB4, Wischhofstrasse 1-3, 24148 Kiel, Germany.
authors.forename: Folkmar
authors.initials: F
authors.lastname: Hauff
authors.affiliation: GNS Science, Private Bag 1930, Dunedin 9054, New Zealand.
authors.forename: Nick
authors.initials: N
authors.lastname: Mortimer
authors.affiliation: GNS Science, PO Box 30-368, Lower Hutt 5040, New Zealand.
authors.forename: Hannu C
authors.initials: HC
authors.lastname: Seebeck
authors.affiliation: National Institute of Water and Atmospheric Research, Private Bag 14901, Wellington 6241, New Zealand.
authors.forename: Richard J
authors.initials: RJ
authors.lastname: Wysoczanski
authors.affiliation: GNS Science, PO Box 30-368, Lower Hutt 5040, New Zealand.
authors.forename: Fabio
authors.initials: F
authors.lastname: Caratori-Tontini
authors.affiliation: School of Geography, Environment and Earth Sciences, Victoria University of Wellington, PO Box 600, Wellington 6140, New Zealand.
authors.forename: John A
authors.initials: JA
authors.lastname: Gamble