Trace-element geochemistry of transform-fault serpentinite in high-pressure subduction mélanges (eastern Cuba): implications for subduction initiation
| Autor: | George E. Harlow, Joaquín A. Proenza, Concepción Lázaro, Cristina Villanova-de-Benavent, K. Núñez Cambra, Idael Francisco Blanco-Quintero, Antonio García-Casco, Juan Cárdenas-Párraga |
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| Rok vydání: | 2017 |
| Předmět: | |
| Zdroj: | International Geology Review. 59:2041-2064 |
| ISSN: | 1938-2839 0020-6814 |
| Popis: | The Sierra del Convento and La Corea melanges (eastern Cuba) are vestiges of a Cretaceous subduction channel in the Caribbean realm. Both melanges contain blocks of oceanic crust and serpentinite subducted to high pressure within a serpentinite matrix. The bulk composition of serpentinite indicates spinel-harzburgite and -herzolite protoliths. The samples preserve fertile protolith signatures that suggest low melting degrees. High concentration of immobile elements Zr, Th, Nb, and REE contents (from ~0.1 to ~2 CI-chondrite) point to early melt–rock interaction processes before serpentinization took place. Major- and trace-element compositions suggest an oceanic fracture-zone–transform-fault setting. A mild negative Eu anomaly in most samples indicates low-temperature fluid–rock interaction as a likely consequence of seawater infiltration during oceanic serpentinization. A second, more important, serpentinization stage is related to enrichment in U, Pb, Cs, Ba, and Sr due to the infiltration of sla... |
| Databáze: | OpenAIRE |
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