Título
Geochemistry and Geochronology of the Guajira Eclogites, northern Colombia: evidence of a metamorphosed primitive Cretaceous Caribbean Island-arc
Autor
Marion Weber
Colaborador
Agustin Cardona (Colaborador)
Victor A Valencia (Colaborador)
Uwe Altenberger (Colaborador)
MARGARITA LOPEZ MARTINEZ (Colaborador)
Marin (Colaborador)
Sebastián (Colaborador)
Judy Marcela Zapata Henao (Colaborador)
Elena Perdomo (Colaborador)
Nivel de Acceso
Acceso Abierto
Identificador alterno
doi: http://dx.doi.org/10.1344/105.000001740
Materias
Resumen o descripción
"The chemical composition of eclogites, found as boulders in a Tertiary conglomerate from the Guajira Peninsula, Colombia suggests that these rocks are mainly metamorphosed basaltic andesites. They are depleted in LILE elements compared to MORB, have a negative Nb-anomaly and flat to enriched REE patterns, suggesting that their protoliths evolved in a subduction related tectonic setting. They show island-arc affinities and are similar to primitive islandarc rocks described in the Caribbean. The geochemical characteristics are comparable to low-grade greenschists from the nearby Etpana Terrane, which are interpreted as part of a Cretaceous intra-oceanic arc. These data support evidence that the eclogites and the Etpana terrane rocks formed from the same volcano-sedimentary sequence. Part of this sequence was accreted onto the margin and another was incorporated into the subduction channel and metamorphosed at eclogite facies conditions. 40Ar-39Ar ages of 79.2±1.1Ma and 82.2±2.5Ma determined on white micas, separated from two eclogite samples, are interpreted to be related to the cooling of the main metamorphic event. The formation of a common volcano-sedimentary protolith and subsequent metamorphism of these units record the ongoing Late Cretaceous continental subduction of the South American margin within the Caribbean intra-oceanic arc subduction zone. This gave way to an arc-continent collision between the Caribbean and the South American plates, where this sequence was exhumed after the Campanian."
Editor
Universitat de Barcelona
Fecha de publicación
2011
Tipo de publicación
Artículo
Versión de la publicación
Versión publicada
Recurso de información
Formato
application/pdf
Fuente
Geologica Acta, Vol. 9, Págs. 425-443
Idioma
Inglés
Sugerencia de citación
Weber,M.B.,Cardona Molina,A.,Valencia,V.A.,Altenberger,U.,López Martínez,M.,Tobón,M.,Zapata Henao,S.,Zapata,G.,Concha,A.E.2011.Geochemistry and Geochronology of the Guajira Eclogites, northern Colombia: evidence of a metamorphosed primitive Cretaceous Caribbean Island-arc.Geologica Acta,9,425-443.doi:10.1344/105.000001740
Repositorio Orígen
Repositorio Institucional CICESE
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