1. Late Jurassic Oceanic Crust and Upper Cretaceous Caribbean Plateau Picritic Basalts Exposed in the Duarte Igneous Complex, Hispaniola
- Author
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Patrick Monié, Marc Tardy, D. Yeghicheyan, Jean Hernandez, Vincent Dupuis, J. Cotten, Mireille Polvé, René C. Maury, Henriette Lapierre, Delphine Bosch, B. Mercier de Lépinay, Institut Dolomieu (géologie), Université Joseph Fourier - Grenoble 1 (UJF)-Centre National de la Recherche Scientifique (CNRS), Géoazur (GEOAZUR 6526), Institut de Recherche pour le Développement (IRD)-Université Pierre et Marie Curie - Paris 6 (UPMC)-Université Nice Sophia Antipolis (1965 - 2019) (UNS), COMUE Université Côte d'Azur (2015-2019) (COMUE UCA)-COMUE Université Côte d'Azur (2015-2019) (COMUE UCA)-Institut national des sciences de l'Univers (INSU - CNRS)-Observatoire de la Côte d'Azur, COMUE Université Côte d'Azur (2015-2019) (COMUE UCA)-Université Côte d'Azur (UCA)-Université Côte d'Azur (UCA)-Centre National de la Recherche Scientifique (CNRS), Université Montpellier 2 - Sciences et Techniques (UM2), Université Savoie Mont Blanc (USMB [Université de Savoie] [Université de Chambéry]), Domaines Océaniques (LDO), Institut national des sciences de l'Univers (INSU - CNRS)-Université de Brest (UBO)-Observatoire des Sciences de l'Univers-Institut d'écologie et environnement-Centre National de la Recherche Scientifique (CNRS), UNIL-BFSH2 Université de Lausanne, Université de Lausanne = University of Lausanne (UNIL), Laboratoire de Géochimie, Université Toulouse - Jean Jaurès (UT2J), Université de Toulouse (UT)-Université de Toulouse (UT)-Université Toulouse III - Paul Sabatier (UT3), and Université de Toulouse (UT)
- Subjects
Basalt ,Geochemistry ,Geology ,Oceanic plateau ,engineering.material ,Picrite basalt ,Igneous rock ,[SDU.STU.GC]Sciences of the Universe [physics]/Earth Sciences/Geochemistry ,Oceanic crust ,Ribbon ,engineering ,Amphibole ,Hornblende - Abstract
International audience; Four distinct rock units have been recognized near El Aguacate, in the Janico–Juncalito–La Vega area of the Duarte complex (Dominican Republic): (1) serpentinites crosscut by numerous diabasic dikes, (2) basalts interbedded with Late Jurassic ribbon cherts, (3) picrites and ankaramites relatively enriched in incompatible trace elements, and (4) amphibolites and gneissic amphibolites chemically similar to Oceanic Plateau Basalts. Similar Ar-Ar ages of late magmatic amphibole from a picrite, and hornblende from an amphibolite ( (86.1 ± 1.3 Ma and 86.7 ± 1.6 Ma respectively), suggest that the Duarte picrites are contemporaneous with the Deep Sea Drilling Program Leg 15 and Ocean Drilling Program Leg 126 basalts drilled from the Caribbean oceanic plateau. These basalts are associated with sediments containing Late Cretaceous faunas. Sr, Nd, and Pb data show that enriched picrites and amphibolites are isotopically similar to mafic lavas from previously described Caribbean plateau and Gala´pagos hotspot basalts. Major element, trace element, and lead isotopic features of Late Jurassic basalts and diabases are consistent with those of normal oceanic crust basalt. However, these basalts differ from typical N-MORB because they have lower eNd ratios that plot within the range of Ocean Island Basalts. These rocks appear to represent remnants of the Caribbean Jurassic oceanic crust formed from an oceanic ridge possibly close to a hotspot. Later, they were tectonically juxtaposed with Late Cretaceous slices of the Caribbean-Colombian plateau.
- Published
- 1999
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