Geochemical characteristics of the Río Verde Complex,Central Hispaniola: Implications for the paleotectonic reconstruction of the Lower Cretaceous Caribbean island-arc |
| |
| Authors: | Javier Escuder-Viruete Andrés Pérez-Estaún Dominique Weis Richard Friedman |
| |
| Institution: | 1. Departamento de Ciencias de la Tierra, Universidad de Zaragoza, Pedro Cerbuna 12, 50009 Zaragoza, Spain;2. Departamento de Geografía y Ordenación del Territorio, Universidad de Zaragoza, Ciudad Escolar s/n, 44003 Teruel, Spain;3. Departamento de Geografía y Ordenación del Territorio, Universidad de Zaragoza, Pedro Cerbuna 12, 50009 Zaragoza, Spain;4. School of Earth Sciences, The University of Melbourne, VIC 3010, Melbourne, Australia;5. Laboratorio de Estratigrafía Biomolecular, Escuela Técnica Superior de Ingenieros de Minas, Ríos Rosas 21, 28003 Madrid, Spain;1. Beijing SHRIMP Center, Chinese Academy of Geological Sciences, 26 Baiwanzhuang Road, 100037 Beijing, China;2. Institut für Geowissenschaften, Johannes Gutenberg-Universität, Becherweg 21, D-55099 Mainz, Germany;3. Departamento de Geociencias, Universidad de los Andes, Cra 1 No 18A – 70, Bogota, Colombia;4. Research School of Earth Sciences, Australian National University, Canberra, ACT 2601, Australia;5. Departamento de Mineralogía y Petrología, Universidad de Granada, Fuentenueva s/n, 18071 Granada, Spain;6. Instituto Andaluz de Ciencias de la Tierra, CSIC-Universidad de Granada, 18100 Armilla, Granada. Spain;7. Department of Earth Sciences, The University of Hong Kong, Pokfulam Road, Hong Kong, China;8. Centro de Investigaciones del Petróleo (CEINPET), Washington No169 esq. a Churruca, 12000 Cerro, Ciudad de la Habana, Cuba;9. Science Facilities Department, Imaging and Analysis Center, Natural History Museum, Cromwell Road, London SW7 5BD, United Kingdom;1. Key Laboratory of Orogenic Belts and Crustal Evolution, Ministry of Education, School of Earth and Space Science, Peking University, Beijing 100871, China;2. Faculty of Science, Kochi University, Akebono-cho 2-5-1, Kochi 780-8520, Japan;3. School of Earth Sciences and Resources, China University of Geosciences Beijing, 29 Xueyuan Road, Beijing 100083, China;1. Departamento de Geología, Universidad de Pinar del Rio, Martí Final # 270, Pinar del Rio 2100, Cuba;2. Departamento de Mineralogía y Petrología, Universidad de Granada, Avda. Fuente Nueva sn, 18002 Granada, Spain;3. Instituto Andaluz de Ciencias de la Tierra, CSIC-Universidad de Granada, Granada, Spain;4. Department of Applied Geology, Curtin University, GPO Box U 1987, Perth, Western Australia 6845, Australia;5. Instituto de Geología y Paleontología, Carretera Vía Blanca y Línea de Ferrocarril, Havana, Cuba |
| |
| Abstract: | New geochronological, trace element and Sr–Nd isotope data for metabasalts, dolerites and amphibolites from the Río Verde Complex, Central Hispaniola, are integrated with existing geochemical data for mafic volcanic rocks and metamorphic derivatives from the Los Ranchos, Amina and Maimón Formations, giving new insights into magma petrogenesis and paleotectonic reconstruction of the Lower Cretaceous Caribbean island-arc–back arc system. U–Pb and 40Ar/39Ar age data show that the Río Verde Complex protoliths were in part coeval with volcanic rocks of the Los Ranchos Formation (Upper Aptian to Lower Albian). The geochemical data establish the existence of gradients in trace element parameters (Nb/Yb, Th/Yb, Zr/Yb, Zr/Ba, and normalized Ti, Sm, Y and Yb abundances) and Nd isotope compositions from throughout Hispaniola, which reflect differences in the degree of mantle wedge depletion and contributions from the subducting slab. The Río Verde Complex mafic rocks and some mafic sills and dykes intruding in the Loma Caribe Peridotite, have a transitional IAT to N-MORB geochemistry and a weak subduction-related signature, and are interpreted to form in a rifted arc or evolving back-arc basin setting. The Los Ranchos, Amina and Maimón Formations volcanic rocks have arc-like characteristics and represent magmatism in the volcanic front. Trace element and Nd isotope modeling reproduce observed data trends from arc to back-arc and suggest that the variations in several geochemical parameters observed in a SW direction across the Caribbean subduction system can be explained from the progressively lower subduction flux into a progressively less depleted mantle source. The low Nb contents and high (εNd)i values in both arc and back-arc mafic rocks imply, however, the absence of a significant Lower Cretaceous plume enriched component. In order to explain these observations, a model of proto-Caribbean oceanic lithosphere subducting to the SW at least in the 120–110 Ma interval, is proposed to cause the observed magmatic variations in the Lower Cretaceous Caribbean island-arc–back-arc system. In this context, arc rifting and initial sea-floor spreading to form the Río Verde Complex protoliths occurred in the back-arc setting of this primitive island-arc, built on the NE edge of the Caribbean plate. |
| |
| Keywords: | |
| 本文献已被 ScienceDirect 等数据库收录！ |
|
