Insights into Fe-Skarn mineralization processes through garnet geochemistry and geochronology in Tibes, Puerto Rico

dc.contributor.advisor Hudgins, Thomas R. Giovannetti Nazario, David A. College of Arts and Sciences - Sciences en_US
dc.contributor.committee Hughes, K. Stephen
dc.contributor.committee Bilenker, Laura D.
dc.contributor.department Department of Geology en_US
dc.contributor.representative Arroyo Caraballo, José R. 2022-12-21T16:28:20Z 2022-12-21T16:28:20Z 2022-12-12
dc.description.abstract The Tibes Skarn is a calcic-iron skarn in southern Puerto Rico containing abundant magnetite and garnet mineralization, the latter of which are significant geochemical tracers of magmatic-hydrothermal activity. These garnets are a grossular-andradite solid solution ranging from 70.85% grossular to 98.79% andradite. Constraints on the fluid chemistry of Tibes are reported, with rare earth element (REEs) concentrations showing light-REE depletion and heavy-REE enrichment, with varying Eu anomalies. These patterns, along with La(n)/Lu(n) < 1, are indicative of nearly neutral to slightly basic pH conditions in a magmatic-hydrothermal system. Concentrations of Zr supports this observation and are also suggestive of relatively high saline fluid conditions. Tibes garnet ages range from 60.28±0.56 Ma and 55.11±0.70 Ma, where the older age represents the timing of ore mineralization. Hence, the Tibes Skarn formed coevally with the Tibes diorite stock and culminated at a time coinciding with the Eocene collision between the NE Caribbean Plate and the Bahamas Platform. en_US
dc.description.abstract El Tibes Skarn es un skarn cálcico de hierro que contiene una abundancia de magnetita y granate, el último siendo un rastreador geoquímico importante de actividad magmática hidrotermal. Estos granates son “grandite”, una solución solida de grosularia y andradita con un rango de 70.85% grosularia y 98.79% andradita. Se reportan datos sobre la química de los fluidos que formaron Tibes, con análisis de elementos lantánidos mostrando patrones de disminución de lantánidos livianos y enriquecimiento de lantánidos pesados, con anomalías variadas de Eu. Estos patrones, con razones de La(n)/Lu(n) < 1, son indicativos de condiciones de pH casi neutrales a levemente básicas en un sistema magmático-hidrotermal. Las concentraciones de Zr apoyan esta observación y también son insinuantes de altas salinidades en los fluidos. Las edades de granates en Tibes tienen un rango de 60.28±0.56 Ma y 55.11±0.70 Ma, donde las edades mayores representa el tiempo de la mineralización de mena. Por lo tanto, el Tibes Skarn se formó al mismo tiempo que la diorita del Tibes stock y culminó en un tiempo coincidiendo con la colisión del Eoceno entre la Placa del Caribe y la plataforma de las Bahamas. en_US
dc.description.graduationSemester Fall en_US
dc.description.graduationYear 2022 en_US
dc.description.sponsorship Reseach was funded through the Geological Society of America's (GSA) Ian S.E. Carmichael Research Award and the Society of Economic Geology's (SEG) Hugh McKinstry Fund. en_US
dc.language.iso en en_US
dc.rights Attribution 4.0 International *
dc.rights.holder (c) 2022 David A. Giovannetti Nazario en_US
dc.rights.uri *
dc.subject Skarn en_US
dc.subject Garnet en_US
dc.subject Geochemistry en_US
dc.subject Geochornology en_US
dc.subject.lcsh Skarn - Puerto Rico
dc.subject.lcsh Garnet - Puerto Rico
dc.subject.lcsh Diorite - Puerto Rico
dc.subject.lcsh Analytical geochemistry
dc.title Insights into Fe-Skarn mineralization processes through garnet geochemistry and geochronology in Tibes, Puerto Rico en_US
dc.type Thesis en_US
dspace.entity.type Publication Geology en_US M.S. en_US
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