Magmatic and geotectonic significance of Santa Elena Peninsula, Costa Rica

We present a new integrated interpretation of the geochemistry and geotectonic significance of the Santa Elena Peninsula, which is divided in three units: 1) an overthrust allocthonous unit of ultramafic and mafic rocks, the Santa Elena Nappe; 2) an autochthonous basaltic sedimentary suite, resting...

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Detalles Bibliográficos
Autores: Gazel, E., Denyer, P., Baumgartner, P. O.
Tipo de recurso: artículo
Fecha de publicación:2006
País:España
Institución:Universitat Autònoma de Barcelona
Repositorio:Dipòsit Digital de Documents de la UAB
Idioma:inglés
OAI Identifier:oai:ddd.uab.cat:86019
Acceso en línea:https://ddd.uab.cat/record/86019
https://dx.doi.org/urn:doi:10.1344/105.000000365
Access Level:acceso abierto
Palabra clave:Santa Elena Peninsula
Oceanic assemblages
Ultramafic Complex
Geochemistry
Accretionary complex
Descripción
Sumario:We present a new integrated interpretation of the geochemistry and geotectonic significance of the Santa Elena Peninsula, which is divided in three units: 1) an overthrust allocthonous unit of ultramafic and mafic rocks, the Santa Elena Nappe; 2) an autochthonous basaltic sedimentary suite, resting immediately below the overthrust, the Santa Rosa Accretionary Complex; and 3) Islas Murciélago pillow and massive basaltic flows. In the Santa Elena Nappe three petrological affinities have been recognized: 1) the ultramafic complex, that corresponds to depleted (MORB-like) mantle serpentinizated peridotites, with very low TiO2 and high Ni and Cr; 2) the pegmatitic gabbros, layered gabbros and plagiogranites and basaltic dikes with low TiO2 (< 0.89%) contents and high LREE depletions; and 3) the doleritic dykes with higher TiO2 (.