Cardiff University | Prifysgol Caerdydd ORCA
Online Research @ Cardiff 
WelshClear Cookie - decide language by browser settings

Origin of the volcanic complexes of La Désirade, Lesser Antilles: implications for tectonic reconstruction of the Late Jurassic to Cretaceous Pacific-proto Caribbean margin

Neill, Iain, Gibbs, Jennifer A., Hastie, Alan R. and Kerr, Andrew Craig 2010. Origin of the volcanic complexes of La Désirade, Lesser Antilles: implications for tectonic reconstruction of the Late Jurassic to Cretaceous Pacific-proto Caribbean margin. Lithos 120 (3-4) , pp. 407-420. 10.1016/j.lithos.2010.08.026

Full text not available from this repository.

Abstract

La Désirade Island is located on the hanging wall of the present-day Lesser Antilles subduction zone and consists of a suite of Mesozoic igneous rocks capped by Neogene limestone. The basement suite contains Kimmeridgian to Tithonian (~153–145 Ma) mafic lava flows and pillow basalts overlain by felsic flows and breccias and intruded by a Mid-Berriasian (~144 Ma) trondhjemite pluton and intermediate to felsic dykes. The mafic rocks form a ~300 m thick sequence which trace element geochemistry reveals to contain, in stratigraphic order: (1) tholeiites with a very weak subduction signature; (2) calc-alkaline and tholeiitic arc rocks containing pelagic and terrigenous sediment slab-related components and (3) arc tholeiites with a minor subduction signature. The mantle wedge source was depleted and did not contain a significant plumerelated component. The overlying felsic rocks show similar trace element patterns and incompatible trace element ratios to the mafic units. Factors such as pelagic sedimentary deposition and re-working, low eruption rates and the presence of MORB-like and felsic rocks are best explained by an origin at a back-arc spreading ridge. This back-arc was most likely in the proto-Caribbean (Colombian Marginal) seaway and was related to east-dipping Andean/Cordilleran subduction. Other sites in the Greater Antilles and Central America older than the ~135 Ma westward acceleration of North America appear to corroborate a latest Jurassic–Early Cretaceous east-dipping arc system. The preservation of La Désirade in the fore-arc of the present Antilles arc is consistent with Mid-to-Late Cretaceous inception of west-dipping subduction along the former back-arc axis which had previously given rise to La Désirade.

Item Type: Article
Date Type: Publication
Status: Published
Schools: Earth and Ocean Sciences
Subjects: Q Science > QE Geology
Uncontrolled Keywords: La Désirade ; Caribbean ; Geochemistry ; Tectonics ; Subduction.
Publisher: Elsevier
ISSN: 0024-4937
Last Modified: 04 Jun 2017 02:08
URI: http://orca.cf.ac.uk/id/eprint/9559

Citation Data

Cited 24 times in Scopus. View in Scopus. Powered By Scopus® Data

Actions (repository staff only)

Edit Item Edit Item