Ophiolite hosted chromitite formed by supra-subduction zone peridotite –plume interaction
| Autor: | Javier Escuder-Viruete, José María González-Jiménez, Francisco Longo, Joaquín A. Proenza, Antonio García-Casco, Vanessa Colás, Thomas Aiglsperger, Júlia Farré-de-Pablo |
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| Přispěvatelé: | Ministerio de Economía y Competitividad (España), Ministerio de Ciencia, Innovación y Universidades (España), Consejo Nacional de Ciencia y Tecnología (México) |
| Rok vydání: | 2020 |
| Předmět: |
Peridotite
Basalt Plume 010504 meteorology & atmospheric sciences Large igneous province lcsh:QE1-996.5 Dominican Republic Geochemistry Ophiolite 010502 geochemistry & geophysics Back-arc basin 01 natural sciences Mantle plume Mantle (geology) lcsh:Geology Chromitite General Earth and Planetary Sciences Chromite Mantle Geology 0105 earth and related environmental sciences |
| Zdroj: | Digital.CSIC. Repositorio Institucional del CSIC instname Digibug: Repositorio Institucional de la Universidad de Granada Universidad de Granada (UGR) Digibug. Repositorio Institucional de la Universidad de Granada Geoscience Frontiers, Vol 11, Iss 6, Pp 2083-2102 (2020) |
| ISSN: | 1674-9871 |
| Popis: | Chromitite bodies hosted in peridotites typical of suboceanic mantle (s.l. ophiolitic) are found in the northern and central part of the Loma Caribe peridotite, in the Cordillera Central of the Dominican Republic. These chromitites are massive pods of small size (less than a few meters across) and veins that intrude both dunite and harzburgite. Compositionally, they are high-Cr chromitites [Cr# ¼ Cr/(Cr þ Al) atomic ratio ¼ 0.71–0.83] singularly enriched in TiO2 (up to 1.25 wt.%), Fe2O3 (2.77–9.16 wt.%) as well as some trace elements (Ga, V, Co, Mn, and Zn) and PGE (up to 4548 ppb in whole-rock). This geochemical signature is unknown for chromitites hosted in oceanic upper mantle but akin to those chromites crystallized from mantle plume derived melts. Noteworthy, the melt estimated to be in equilibrium with such chromite from the Loma Caribe chromitites is similar to basalts derived from different source regions of a heterogeneous Caribbean mantle plume. This mantle plume is responsible for the formation of the Caribbean Large Igneous Province (CLIP). Dolerite dykes with back-arc basin basalt (BABB) and enriched mid-ocean ridge basalt (E-MORB) affinities commonly intrude the Loma Caribe peridotite, and are interpreted as evidence of the impact that the Caribbean plume had in the off-axis magmatism of the back-arc basin, developed after the Caribbean island-arc extension in the Late Cretaceous. We propose a model in which chromitites were formed in the shallow portion of the back-arc mantle as a result of the metasomatic reaction between the supra-subduction zone (SSZ) peridotites and upwelling plume-related melts. European Union (EU) Spanish Ministerio de Economia y Competitividad (MINECO) CGL2015-65824 Ministerio de Glenda, Innovation y Universidades (MICINN) RTI2018-099157-A-100 Ramon y Cajal Fellowship (MICINN) RYC-2015-17596 MINECO BES-2016-076887 Mexican research programs Glenda Basica - Consejo Nacional de CiencM y Tecnologia (CONACYT) from Mexico Al -S14574 Programa de Apoyo a Proyectos de Investigation e Innovation tecnologica - UNAM IA-101419 University of Barcelona University of Granada, Spain |
| Databáze: | OpenAIRE |
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