3D geological modeling of the Trujillo block: insights for crustal escape models of the Venezuelan Andes

dc.contributor.authorDhont, D.
dc.contributor.authorMonod, B.
dc.contributor.authorHervouët, Y.
dc.contributor.authorBacké, G.
dc.contributor.authorKlarica, S.
dc.contributor.authorChoy, J.
dc.date.issued2012
dc.description.abstractThe Venezuelan Andes form a N50°E-trending mountain belt extending from the Colombian border in the SW to the Caribbean Sea in the NE. The belt began to rise since the Middle Miocene in response to the E-W collision between the Maracaibo block to the NW and the Guyana shield belonging to South America to the SE. This oblique collision led to strain partitioning with (1) shortening along opposite-vergent thrust fronts, (2) right-lateral slip along the Boconó fault crossing the belt more or less along-strike and (3) crustal escape of the Trujillo block moving towards the NE in between the Boconó fault and the N-S-striking left-lateral Valera fault. The geology of the Venezuelan Andes is well described at the surface, but its structure at depth remains hypothetic. We investigated the deep geometry of the Mérida Andes by a 3D model newly developed from geological and geophysical data. The 3D fault model is restricted to the crust and is mainly based on the surface data of outcropping fault traces. The final model reveals the orogenic float concept where the mountain belt is decoupled from its underlying lithosphere over a horizontal décollement located either at the upper/lower crust boundary. The reconstruction of the Boconó and Valera faults results in a 3D shape of the Trujillo block, which floats over a mid-crustal décollement horizon emerging at the Boconó-Valera triple junction. Motion of the Trujillo block is accompanied by a widespread extension towards the NE accommodated by normal faults with listric geometries such as for the Motatan, Momboy and Tuñame faults. Extension is explained by the gravitational spreading of the upper crust during the escape process. © 2012 Elsevier Ltd.
dc.description.statementofresponsibilityDamien Dhont, Bernard Monod, Yves Hervouët, Guillaume Backé, Stéphanie Klarica, José E. Choy
dc.identifier.citationJournal of South American Earth Sciences, 2012; 39:245-251
dc.identifier.doi10.1016/j.jsames.2012.04.003
dc.identifier.issn0895-9811
dc.identifier.urihttp://hdl.handle.net/2440/105578
dc.language.isoen
dc.publisherElsevier
dc.rights© 2012 Elsevier Ltd. All rights reserved.
dc.source.urihttps://doi.org/10.1016/j.jsames.2012.04.003
dc.subjectVenezuela; 3D model; orogenic float; tectonic escape
dc.title3D geological modeling of the Trujillo block: insights for crustal escape models of the Venezuelan Andes
dc.typeJournal article
pubs.publication-statusPublished

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