Serpentinites and serpentinites within a fossil subduction channel : La Corea mélange, eastern Cuba
Blanco-Quintero, Idael Francisco (Universidad de Granada. Departamento de Mineralogía y Petrología)
Proenza, J. A. (Universitat de Barcelona. Departament de Cristal·lografia, Mineralogia i Dipòsits Minerals)
García-Casco, A. (Instituto Andaluz de Ciencias de la Tierra)
Tauler, E. (Universitat de Barcelona. Departament de Cristal·lografia, Mineralogia i Dipòsits Minerals)
Galí, S. (Universitat de Barcelona. Departament de Cristal·lografia, Mineralogia i Dipòsits Minerals)

Date:	2011
Abstract:	A variety of metaultramafic (serpentinite) rocks in La Corea mélange, Sierra de Cristal, eastern Cuba, show differences in chemical, textural and mineralogical characteristics demonstrating a variety of protoliths. The mélange originated during the Cretaceous as part of the subduction channel associated with the Caribbean island arc. This mélange contains high pressure blocks in a serpentinite matrix and occurs at the base of the large tabular Mayarí-Cristal ophiolite. Two principal groups of serpentinites have been identified in the mélange: a) antigorite serpentinite, mainly composed of antigorite and b) antigorite-lizardite serpentinite, composed of mixtures of antigorite and lizardite and bearing distinctive porphyroblasts of diopsidic clinopyroxene. Antigorite serpentinites are closely related to tectonic blocks of amphibolite (representing subducted MORB) and constitute deep fragments of the serpentinitic subduction channel formed during hydration of the mantle wedge. The composition of the antigorite-lizardite serpentinites and the presence of clinopyroxene porphyroblasts in this type of rock suggest that abyssal lherzolite protoliths transformed into serpentinite before and during incorporation (as tectonic blocks) in the shallow part of the subduction channel. Although the studied rocks have different origin, mineralogical compositions and textures, they display similar PGE compositions, suggesting that these elements experienced no significant redistribution during metamorphism. Both types of serpentinites were exposed together in the La Corea mélange during the Late Cretaceous, during obduction of the overriding Mayarí-Baracoa ophiolitic belt that led to exhumation of the subduction channel (mélange).
Rights:	Aquest document està subjecte a una llicència d'ús Creative Commons. Es permet la reproducció total o parcial, la distribució, la comunicació pública de l'obra i la creació d'obres derivades, fins i tot amb finalitats comercials, sempre i quan aquestes es distribueixin sota la mateixa llicència que regula l'obra original i es reconegui l'autoria de l'obra original.
Language:	Anglès
Document:	Article ; recerca ; Versió publicada
Subject:	Serpentinite ; Subduction Channel ; La Corea Mélange ; Cuba ; Caribbean
Published in:	Geologica acta, Vol. 9, Núm. 3-4 (setembre-desembre 2011) , p. 389-405, ISSN 1696-5728

Adreça alternativa: https://raco.cat/index.php/GeologicaActa/article/view/247928
Adreça alternativa: https://revistes.ub.edu/index.php/GEOACTA/article/view/105.000001662
DOI: 10.1344/105.000001662

17 p, 6.8 MB

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