The OIB signature in Central America: old lithospheric and young asthenospheric mantle reservoirs.

Gazel, Esteban, Feigensohn, Mark, Carr, Michael J. and Hoernle, Kaj (2010) The OIB signature in Central America: old lithospheric and young asthenospheric mantle reservoirs. [Talk] In: 20. Annual Goldschmidt Conference: Earth, Energy and Environment. , 13.06.-19.06.2010, Knoxville, Tennessee, USA . Geochimica et Cosmochimica Acta. ; A322 .

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Abstract

Although most Central American magmas have a depleted MORB-source mantle (fluxed by subduction-derived fluids), magmas in southern Central America have isotopic and trace element compositions with a Galapagos affinity. How Galapagos-influenced signature was introduced into the Central American mantle is at the heart of conflicting theories [e.g. 1, 2, 3]. Our new data for Costa Rica suggest that this signature has a relatively recent origin (~6 Ma) [4, 5]. REE inverse modelling [6] results indicate that garnet is not present in the distal back-arc region. In contrast, adakites from Central America, as well as volcanic front lavas and alkaline lavas from central Costa Rica (Fig. 1) and Panama, require garnet in the source. Garnet-present sources (<6 Ma) close to the volcanic front in Costa Rica and Panama suggest that the Galapagos-related reservoir can be either asthenospheric or recycled (subducting Galapagos tracks). The garnet-free source (>12 Ma) in the distal back-arc suggests that there is another enriched reservoir stored in the lithosphere, predating any recent subduction-generated or asthenospheric flow

Document Type: Conference or Workshop Item (Talk)
Additional Information: DOI:10.1016/j.gca.2010.04.032
Keywords: Volcanology
Research affiliation: OceanRep > GEOMAR > FB4 Dynamics of the Ocean Floor > FB4-MUHS
Publisher: Elsevier
Date Deposited: 24 Nov 2010 14:25
Last Modified: 23 Feb 2012 05:27
URI: https://oceanrep.geomar.de/id/eprint/10138

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