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dc.contributor.advisorRamírez-Martínez, Wilson R.
dc.contributor.authorMorales-Collazo, Jose A.
dc.date.accessioned2017-08-28T19:53:29Z
dc.date.available2017-08-28T19:53:29Z
dc.date.issued2015
dc.identifier.urihttps://hdl.handle.net/20.500.11801/53
dc.description.abstractTemperatures during the Holocene are driven by seasonal changes in insolation; however, a better understanding of insolation mechanisms and how it affects tropical climate is still necessary. This study presents annual growth rates seasonally resolved oxygen and carbon isotopic and Sr/Ca trace elemental variations from five fossils Montastraea sp. corals from Cañada Honda Enriquillo Valley, Dominican Republic. U/Th dates obtained from fossil corals in M1 facies indicate earlymid Holocene dates ranging from 8.0-8.9 ka B.P. The aragonite skeleton composition was confirmed by X-ray diffraction. Growth rates in Montastraea sp. corals, with a record of 30-80 years, collected at this site, range from 2.07 ± 0.14 to 3.55 ± 0.37 mm/yr (n=5). High sedimentation rates in the reef were estimated to range from 1.53 ± 0.18 to 2.48 ± 0.45 mm/yr (n=8). δ 18O measurements range from -0.69 to -2.41 (n=430) values that are heavier relative to modern corals from the tropics by ~2‰. Sr/Ca measurements range from 9.07 to 9.70 mmol/mol (n=430), values higher than modern corals from the tropics. Both proxies suggest colder environments during this time period. Calculated SST for each variable suggest temperature variations of 6°-7°C values never reported by any proxy from the Early Holocene, but may be explained by periods of freshwater influx. A low correlation index (R) estimated (0.26-0.85) suggests that both paleothermomethers are reacting to different variables.
dc.description.abstractLas temperaturas durante el Holocene son impulsadas por cambios estacionales en insolación, sin embargo, un mejor entendimiento de los mecanismos de insolación y como estos afectan el clima en los trópicos es aun necesario. Este estudio presenta tasas de crecimientos anual resuelto estacionalmente por variaciones isotópicas de oxígeno y carbono, y elementos traza Sr/Ca en cinco corales fósiles de la especie Montastraea sp. en Cañada Honda, Valle Enriquillo, Republica Dominicana. Dataciones de U/Th obtenidas de corales fósiles en facies M-1 indican edades del Holoceno temprano-tardío que oscilan entre 8.0-8.9 kya A.P. La composición del esqueleto aragonítico fueron confirmados en un análisis de XRD. La tasa de crecimiento en corales Monstrastraea sp., en un récord de 30-80 años, colectados en esta zona, varían entre 2.07 ± 0.14 to 3.55 ± 0.37 mm/yr (n=5). Las altas tasas de sedimentación en el arrecife fueron estimadas y varían entre 1.53 ± 0.18 to 2.48 ± 0.45 mm/yr (n=8). Medidas de δ 18O varían entre -0.69 to -2.41 (n=430), valores pesados relativo a corales modernos en el trópico por ~2‰. Medidas de Sr/Ca varían entre 9.07 to 9.62 mmol/mol (n=430) , valores más altos, que corales modernos en el trópico. Las TSM calculadas para cada variable sugieren variaciones en temperatura de 6°-7°C. Valores como estos no han sido reportados por ningún proxy durante el Holoceno temprano. El bajo índice de correlación (R) estimado (0.02-0.85) sugiere que ambos paleotermometros estan reaccionando a diferentes variables.
dc.description.sponsorshipExxon Mobil-UPRM Diversity Awarden_US
dc.language.isoenen_US
dc.subjectCoral mineralogyen_US
dc.subjectMontastraea sp.en_US
dc.subjectEarly-mid Holoceneen_US
dc.subject.lcshOcean temperature--Dominican Republic--Enriquillo Valley--Canada Hondaen_US
dc.subject.lcshGeology, Stratigraphic--Holoceneen_US
dc.subject.lcshOcean temperature--Caribbean Areaen_US
dc.titleReconstructing sea surface temperatures in the Caribbean during the early-mid Holocene from a reef exposure in Cañada Honda, Enriquillo Valley, Dominican Republicen_US
dc.typeThesisen_US
dc.rights.licenseAll rights reserveden_US
dc.rights.holder(c) 2015 Jose A. Morales Collazoen_US
dc.contributor.committeeRomán Velázquez, Félix R.
dc.contributor.committeeWinter, Amos
dc.contributor.committeeSantos Mercado, Hernán
dc.contributor.representativeMorell Rodríguez, Julio M.
thesis.degree.levelM.S.en_US
thesis.degree.disciplineGeologyen_US
dc.contributor.collegeCollege of Arts and Sciences - Sciencesen_US
dc.contributor.departmentDepartment of Geologyen_US
dc.description.graduationSemesterSpringen_US
dc.description.graduationYear2015en_US


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