dc.contributor.advisor	Avé Lallemant, Hans G.	en_US
dc.creator	Ostos Rosales, Marino	en_US
dc.date.accessioned	2009-06-04T00:34:50Z	en_US
dc.date.available	2009-06-04T00:34:50Z	en_US
dc.date.issued	1990	en_US
dc.description.abstract	Northern Venezuela consists of seven east-west trending tectonostratigraphic belts which are from north to south: Dutch and Venezuelan islands (DVI), Venezuelan platform, Cordillera de la Costa-Margarita terrane (CCMT), Cordillera de la Costa belt (CCB), Caucagua-El Tinaco belt (CTB), Paracotos belt (PB), and Villa de Cura belt (VCB). Geochemical, metamorphic, and structural data were collected in several transects through these belts. Major- and trace-element abundances in mafic and felsic rocks were determined to find the tectonic affinity of these rocks. The Precambrian basement of the CCB appears to consist of within-plate granites. The Paleozoic basement of the CTB consists of MORB's, Andean-type tholeiites, and arc granites. The mafic rocks of Mesozoic age have variable affinities: the DVI, CCMT, and VCB are underlain by MORB's, but part of the VCB has volcanic arc affinity. All felsic rocks of Mesozoic age in the DVI and CCMT are arc granites. Several periods of metamorphism have occurred in Venezuela in Precambrian and Paleozoic time. An important metamorphic event occurred in the Cretaceous. The CCMT and VCB underwent high P/low T metamorphism and subsequently low to intermediate P/T metamorphism. These events may be related to subduction and subsequent uplift, respectively. The CCB underwent an intermediate P/T metamorphism, because it probably has never been buried as deeply. The PB underwent very low-grade metamorphism possibly related to the obduction of ophiolitic thrust sheets. Four generations of folds and three generations of faults were recognized. The first two phases of folding occurred probably in the Permian and the last two during a Late Cretaceous-Tertiary orogeny. Kinematic indicators suggest that the entire system underwent dextral shear parallel to the belts during the Late Cretaceous-Tertiary. Based on the available geologic data, a plate tectonic model is proposed. In the model the east-west trending belts of northern South America are allochthonous and deformed as a result of collision of a microcontinent (Sebastopol block) with northwestern South America. The belts were initially coupled to the overriding South American plate, but because of the large obliquity of plate convergence were transported easterly since the Late Cretaceous.	en_US
dc.format.extent	459 p.	en_US
dc.format.mimetype	application/pdf	en_US
dc.identifier.callno	Thesis Geol. 1990 OstosRosales	en_US
dc.identifier.citation	Ostos Rosales, Marino. "Tectonic evolution of the south-central Caribbean based on geochemical data." (1990) Diss., Rice University. <a href="https://hdl.handle.net/1911/16380">https://hdl.handle.net/1911/16380</a>.	en_US
dc.identifier.uri	https://hdl.handle.net/1911/16380	en_US
dc.language.iso	eng	en_US
dc.rights	Copyright is held by the author, unless otherwise indicated. Permission to reuse, publish, or reproduce the work beyond the bounds of fair use or other exemptions to copyright law must be obtained from the copyright holder.	en_US
dc.subject	Geophysics	en_US
dc.title	Tectonic evolution of the south-central Caribbean based on geochemical data	en_US
dc.type	Thesis	en_US
dc.type.genre	maps	en_US
dc.type.material	Text	en_US
thesis.degree.department	Earth Science	en_US
thesis.degree.discipline	Natural Sciences	en_US
thesis.degree.grantor	Rice University	en_US
thesis.degree.level	Doctoral	en_US
thesis.degree.name	Doctor of Philosophy	en_US

Tectonic evolution of the south-central Caribbean based on geochemical data

Files

Original bundle

Collections