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dc.contributor.advisorSnow, Jonathan E.
dc.creatorGiblin, Allegra Catherine Thibodaux 1979-
dc.date.accessioned2017-08-17T17:24:07Z
dc.date.available2017-08-17T17:24:07Z
dc.date.createdAugust 2015
dc.date.issued2015-08
dc.date.submittedAugust 2015
dc.identifier.urihttp://hdl.handle.net/10657/2025
dc.description.abstractThe Central American Land Bridge is the crucial connection between North and South America, and the Miocene closure of the Panama seaway led to a change in global oceanic circulation patterns. Modern Costa Rica is part of the island arc that formed over the western Caribbean subduction zone, and the Santa Elena peninsula is on the northwest coast of Costa Rica next to the Sandino forearc basin. This study focuses on the origin and provenance of the Paleocene deep water Rivas and Descartes turbidites that crop out on the northern part of the Santa Elena peninsula in northwestern Costa Rica. Understanding the sedimentary fill of the Sandino Basin that contributed to the closing of the seaway may lead to a better understanding of the Late Cretaceous-Paleogene arcs. Provenance studies of the Santa Elena Peninsula turbidite sandstone bodies constrain the history of the paleogeography and tectonics of the region. Petrographic analyses of rock thin sections constrain source areas; geochemical analysis of individual detrital heavy minerals from rock samples give indications of sediment sources and tectonic setting during deposition. This study is a provenance analysis based on (i) semi-quantitative energy-dispersive spectrometry analysis of heavy minerals, (ii) quantitative wavelength-dispersive spectrometry for major elements of detrital clinopyroxene and spinel grains, (iii) trace element analysis through laser ablation of single detrital clinopyroxene grains, and (iv) comparative analysis of the different potential source rocks to clearly identify the most likely sediment sources. The detrital spinel and clinopyroxene are possibly sourced from: mantle ophiolites, mid-ocean ridge gabbros, or volcanic arc tholeiitic basalts or calc-alkaline andesites. Spinel and clinopyroxne geochemistry suggests a possible peridotitic source, linked to mantle rocks that are now covered by Tertiary volcanic rocks or have completely eroded. The character of the crustal minerals indicates sources from mid-ocean ridge gabbros, and island arc tholeiites and andesites. This suggests that during the early history of the gateway uplift and seaway closure, sediment sources were dominated first by older ophiolites and gabbroic sources, then by volcanic inputs from the arc.
dc.format.mimetypeapplication/pdf
dc.language.isoeng
dc.subjectclinopyroxene
dc.subjectspinel
dc.subjectgeochemistry
dc.subjectmajor element
dc.subjecttrace element
dc.subjectmicroprobe
dc.subjectLA-ICP-MS
dc.subjectturbidite
dc.subjectCosta Rica
dc.subjectSanta Elena
dc.subjectRivas
dc.subjectDescartes
dc.subjectHFSE
dc.subjectPaleocene arc
dc.titlePaleocene Turbidite Deposition in the Central American Seaway (NW Costa Rica): Geochemical Analysis and Provenance of Detrital Spinel and Clinopyroxene
dc.date.updated2017-08-17T17:24:07Z
dc.type.genreThesis
thesis.degree.nameMaster of Science
thesis.degree.levelMasters
thesis.degree.disciplineGeology
thesis.degree.grantorUniversity of Houston
dc.contributor.committeeMemberGazel, Esteban
dc.contributor.committeeMemberSisson, Virginia
dc.contributor.committeeMemberSaylor, Joel E.
dc.creator.orcid0000-0003-4392-9920
dc.type.dcmitext
dc.format.digitalOriginborn digital
dc.description.departmentEarth and Atmospheric Sciences
thesis.degree.collegeCollege of Natural Sciences and Mathematics


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