georefid:2000-041271SEDIS Publication Catalogue

ana.macario@awi.de

http://sedis.iodp.org/pub-catalogue/informationpointOfContact2011-06-23T00:00:00Zhttp://sedis.iodp.org/pub-catalogue/index.php?id=2000-0412711999-01-01publicationgeorefid:2000-041271Lapierre, HenrietteUniversite Joseph Fourier, Grenoble, FranceauthorDupuis, VincentUniversite de Montpellier II, FranceauthorMercier de Lepinay, BernardUniversite de Savoie, FranceauthorBosch, DelphineUniversite de Bretagne Occidentale, FranceauthorMonie, PatrickUniversite de Lausanne, SwitzerlandauthorTardy, MarcUniversite Paul Sabatier, FranceauthorMaury, Rene C.authorHernandez, JeanauthorPolve, MireilleauthorYeghicheyan, DelphineauthorCotten, JosephauthorUniversity of Chicago Press, Chicago, IL, United StatespublisherdocumentHardcopyJournal of Geology107 (2)193-207Four 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 + or - 1.3 Ma and 86.7 + or - 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 Galapagos 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 epsilon Nd 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.completedIsotope geochemistryIgneous and metamorphic petrologyabsolute agealkaline earth metalsamphibolitesankaramiteAntillesAr/ArbasaniteCaribbean PlateauCaribbean regionCretaceouscrustdatesDominican RepublicDuarte ComplexEl Aguacate Dominican RepublicenrichmentgeochemistryGreater AntillesHispaniolaigneous rocksisotope ratiosisotopesJanico Dominican RepublicJuncalito Dominican RepublicJurassicLa Vega Dominican Republicleadlithogeochemistrymajor elementsMesozoicmetaigneous rocksmetalsmetamorphic rocksmetasomatic rocksNd-144/Nd-143neodymiumoceanic crustPb-206/Pb-204Pb-207/Pb-204Pb-208/Pb-204picriteradioactive isotopesrare earthsserpentiniteSr-87/Sr-86stable isotopesstrontiumtrace elementsultramafic compositionUpper CretaceousUpper Jurassicvolcanic rocksWest IndiesEnglishgeoscientificInformation-70.0805-70.080018.360018.3700