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Cretaceous fore-arc basalts from the Tonga arc: geochemistry and implications for the tectonic history of the SW Pacific

Citation

Falloon, TJ and Meffre, S and Crawford, AJ and Hoernle, K and Hauff, F and Bloomer, SH and Wright, DJ, Cretaceous fore-arc basalts from the Tonga arc: geochemistry and implications for the tectonic history of the SW Pacific, Tectonophysics, 630 pp. 21-32. ISSN 0040-1951 (2014) [Refereed Article]

Copyright Statement

Copyright 2014 Elsevier

DOI: doi:10.1016/j.tecto.2014.05.007

Abstract

The Tonga fore-arc preserves a complex history of subduction initiation, back-arc basin formation and arc volcanism which has extended from the Cretaceous to the present. In this paper, we discuss the geochemistry of a Cretaceous basalt/dolerite/gabbro suite recovered in two dredges from the Tonga fore-arc at ~19S. The geochemistry of the Tonga fore-arc suite is unlike that of the uniformly depleted MORB basalts of the subducting Pacific Plate and therefore is unlikely to be accreted from Pacific Cretaceous crust. The ~102Ma age obtained for one Tongan fore-arc dolerite is contemporaneous with a major phase of Cretaceous subduction-related volcanism, recorded both in detrital zircon age populations and associated volcanics from New Caledonia and New Zealand. We believe that the Tonga fore-arc basalts are a remnant of a hypothesized, once extensive Cretaceous back-arc basin, called the East New Caledonia Basin, which we propose to have existed from ~102 to 50Ma. The allochthonous Poya Terrane of New Caledonia is geochemically very similar to the Tonga fore-arc basalts and represents a younger (~8455Ma) remnant of the same basin. Subduction-related Cretaceous volcanics from the SW Pacific, representing both arc and back-arc settings, all appear to have similar Zr/Nb values, suggesting a common mantle component in their petrogenesis. The Tonga fore-arc basalts are also similar to fore-arc basalts recovered from the Izu-Bonin-Mariana fore-arc, but unlike these basalts they are not associated with subduction initiation.

Item Details

Item Type:Refereed Article
Keywords:Tonga, forearc basalts, SW Pacific tectonics, Cretaceous, babb
Research Division:Earth Sciences
Research Group:Geochemistry
Research Field:Inorganic Geochemistry
Objective Division:Expanding Knowledge
Objective Group:Expanding Knowledge
Objective Field:Expanding Knowledge in the Earth Sciences
Author:Falloon, TJ (Dr Trevor Falloon)
Author:Meffre, S (Dr Sebastien Meffre)
Author:Crawford, AJ (Professor Anthony Crawford)
ID Code:96729
Year Published:2014
Web of Science® Times Cited:6
Deposited By:Earth Sciences
Deposited On:2014-11-18
Last Modified:2017-11-02
Downloads:0

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