A genetic link between silicic slab components and calc-alkaline arc volcanism in central Mexico


Por: Straub S.M., Zellmer G.F., Gómez-Tuena A., Espinasa-Pereñ A. R., Martin-Del Pozzo A.L., Stuart F.M., Langmuir C.H.

Publicada: 1 ene 2014
Resumen:
A fundamental question in the formation of orogenic andesites is whether their high melt SiO2 reflects the recycling of silicic melts from the subducted slab or the processing of basaltic mantle melts in the overlying crust. The latter model is widely favoured, because most arc magmas lack the 'garnet' signature of partial slab melts. Here we present new trace element data from Holocene high-Mg# >64-72 calc-alkaline basalts to andesites (50-62 wt% SiO2) from the central Mexican Volcanic Belt that crystallize high-Ni olivines with the high 3He/4He = 7-8 of the upper mantle. These magmas have been proposed to be partial melts from 'reaction pyroxenites', which formed by hybridization of mantle peridotite (c. 82-85%) and heavy rare earth elementdepleted silicic slab melt (>15-18%). Forward and inverse models suggest that the absence of a garnet signature in these melts reflects the efficient buffering of the heavy rare earth elements (Ho to Lu) in the subarc mantle. In contrast, all elements more incompatible than H-excepting TiO2-are more or less strongly controlled by the silicic slab flux that also directly contributes to the silicic arc magma formation. Our study emphasizes the strong link between slab recycling and the genesis of orogenic andesites. © The Geological Society of London 2014.

Filiaciones:
Straub S.M.:
 Lamont Doherty Earth Observatory, Columbia University, 61 Route 9W, Palisades NY 10964, United States

Zellmer G.F.:
 Institute of Earth Sciences, Academia Sinica, 128 Academia Road,Sec. 2, Nankang, Taipei 11529,, Taiwan

 Institute of Agriculture and Environment, Massey University, Palmerston North 4442, New Zealand

Gómez-Tuena A.:
 Centro de Geociencias, Universidad Nacional Autónoma de México, Querétaro 76230, Mexico

Espinasa-Pereñ A. R.:
 Centro Nacional de Prevención de Desastres, Secretarla de Gobernación, Av. Delfln Madrigal 665, Col. Pedregal de Santo Domingo, C.P. 04360 Delegacion Coyoacan, Mexico D.F., Mexico

Martin-Del Pozzo A.L.:
 Instituto de Geofisica, Universidad Nacional Autonoma de Mexico, Ciudad Universitaria, Mexico, D.F. 04510, Mexico

Stuart F.M.:
 Isotope Geosciences Unit, Scottish Universities Research and Reactor Centre, East Kilbride G75 0QF, United Kingdom

Langmuir C.H.:
 Department of Earth and Planetary Sciences, Harvard University, 20 Oxford Street, Cambridge, MA 02137, United States
ISSN: 03058719
Editorial
Geological Society of London, UNIT 7, BRASSMILL ENTERPRISE CTR, BRASSMILL LANE, BATH BA1 3JN, AVON, ENGLAND, Reino Unido
Tipo de documento: Article
Volumen: 385 Número: 1
Páginas: 31-64
WOS Id: 000342894900004