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Lithological And Geochemical Responses To Abrupt Global And Regional Paleoenvironmental Changes During The Aptian In A Hemipelagic Setting Of The Eastern Iberian Peninsula: A Multi-Proxy Approach, Jander Socorro

FIU Electronic Theses and Dissertations

Intense episodes of environmental perturbations and regionally to globally distributed, oxygen-deprived marine facies characterize the Cretaceous sedimentary record. The Organyà Basin in the Spanish Pyrenees chronicles this period in expanded stratigraphic sequences that enabled high-resolution sampling and detailed analysis of disturbances poorly recorded in more lithologically condensed sections. Here, I present an integrated multi-proxy study aimed at understanding the Basin’s response to changing paleoenvironmental conditions during the early Aptian stage of the Cretaceous.

Results from the El Pui section indicate that large-scale (> 1‰), negative carbon isotope excursions (CIEs) that show no corresponding shifts in local sources of organic matter …

Identifying The Origins Of Volcanic Ash Deposits Using Their Chemical And Physical Compositions, Emmanuel Soto

FIU Electronic Theses and Dissertations

Recent ocean sediments collected offshore Chile by Ocean Drilling Program Leg 202 contained layers of volcanic ash of unknown origin. These deposits may have originated from sources in the Southern Volcanic Zone (SVZ) within the Andean Volcanic Belt to the east, or from explosive volcanoes in the southwestern Pacific transported by westerly prevailing winds. In this study, mineral and glass textures and compositions of Leg 202 ashes were evaluated to try to determine the sources of the ash layers. Ash fragments were imaged and analyzed for major elements using an SEM with X-Ray detector and for trace elements using LA-ICPMS. …

Hydrologic Controls Of Coastal Groundwater Discharge In Southern Taylor Slough, Everglades National Park, Florida, Edward Linden

FIU Electronic Theses and Dissertations

This project empirically determined the controls of groundwater discharge potential and surface water chemistry in southern Taylor Slough, Everglades National Park, Florida. Potential for groundwater discharge was calculated as the difference in equivalent freshwater stage between groundwater and surface water on a daily basis for two sites (upland and coastal) along southern Taylor Slough. Upstream water stages were shown to vary most similarly to the timing of groundwater discharge potential in coastal Taylor Slough. Surface water major ion chemistry did not apparently change as a result of groundwater discharge potential. Surface water major ion chemistry at the coastal site was …

Arc Crust-Magma Interaction In The Andean Southern Volcanic Zone From Thermobarometry, Mineral Composition, Radiogenic Isotope And Rare Earth Element Systematics Of The Azufre-Planchon-Peteroa Volcanic Complex, Chile, Sven P. Holbik

FIU Electronic Theses and Dissertations

The Andean Southern Volcanic Zone (SVZ) is a vast and complex continental arc that has been studied extensively to provide an understanding of arc-magma genesis, the origin and chemical evolution of the continental crust, and geochemical compositions of volcanic products. The present study focuses on distinguishing the magma/sub-arc crustal interaction of eruptive products from the Azufre-Planchon-Peteroa (APP 35°15’S) volcanic center and other major centers in the Central SVZ (CSVZ 37°S - 42°S), Transitional SVZ (TSVZ 34.3-37.0°S), and Northern SVZ (NSVZ 33°S - 34°30’S). New Hf and Nd isotopic and trace element data for SVZ centers are consistent with former studies …

A Geochemical Study Of Crustal Plutonic Rocks From The Southern Mariana Trench Forearc: Relationship To Volcanic Rocks Erupted During Subduction Initiation, Julie A. Johnson

FIU Electronic Theses and Dissertations

Two suites of intermediate-felsic plutonic rocks were recovered by dredges RD63 and RD64 (R/V KK81-06-26) from the northern wall of the Mariana trench near Guam, which is located in the southern part of the Izu-Bonin-Mariana (IBM) island arc system. The locations of the dredges are significant as the area contains volcanic rocks (forearc basalts and boninites) that have been pivotal in explaining processes that occur when one lithospheric plate initially begins to subduct beneath another. The plutonic rocks have been classified based on petrologic and geochemical analyses, which provides insight to their origin and evolution in context of the surrounding …

Lower Aptian Comparative Stratigraphy Of The Basco-Cantabrian Region (Spain) And Eastern Cordillera (Colombia): Implications For Local Factors In The Depositional Record Of Oceanic Anoxic Event 1a (Oae-1a), Tatiana Gaona Narvaez

FIU Electronic Theses and Dissertations

An important episode of carbon sequestration, Oceanic Anoxic Event 1a (OAE-1a), characterizes the Lower Aptian worldwide, and is mostly known from deeper-water settings. The present work of two Lower Aptian deposits, Madotz (N Spain) and Curití Quarry (Colombia), is a multiproxy study that includes fossil assemblages, microfacies, X-ray diffraction bulk and clay mineralogy, elemental analyses (major, minor, trace elements), Rock-Eval pyrolysis, biomarkers, inorganic and organic carbon content, and stable carbon isotopes. The results provide baseline evidence of the local and global controlling environmental factors influencing OAE-1a in shallow-water settings. The data also improve our general understanding of the conditions under …

U-Th-Ba Elemental Fractionation During Partial Melting Of Crustal Xenoliths And Its Implications For U-Series Disequilibria In Continental Arc Rocks, Raul Brens Jr.

FIU Electronic Theses and Dissertations

Understanding U-series isotopic disequilibria of partially melted crust is integral for determining the effect that crustal assimilation has on the U-series signature of magmas. In this work, U, Th and Ba (as a proxy for Ra) elemental abundances were gathered on the quenched glass in partially melted crustal xenoliths of granitic composition using microbeam techniques. The crustal xenoliths, which are found in basaltic lava, from Mirador Volcano in Chile, are old, and can be assumed to be at secular equilibrium, whereas melting occurred during eruption of Mirador in 1979. A comparison of the ratios Ba/Th and U/Th in the partial …

Paleoenvironmental Implications Of The Indidura Formation (Cenomanian/Turonian), Northeastern Mexico: A High Resolution Stratigraphic Study, Fabian Duque-Botero

FIU Electronic Theses and Dissertations

High-resolution lithostratigraphic data from rock sequences known as the Indidura Formation near Parras de La Fuente, Coahuila, NE Mexico, led to achieve a significant improvement of our knowledge of that Formation. The results of this study indicate for the first time that the sequence at Parras de La Fuente developed from the deposition of calcareous cyanobacterial microspheroids that accumulated under perennial blooms during the Late Cenomanian through the Middle Turonian. Multi-proxy analyses included sedimentological, petrographical, scanning electron microscopy, stable isotope, trace element geochemistry, and paleontological data. The combined results allowed the correlation of δ13C and anomalies in Mo, V, and …

Petrology And Geochemistry Of Some High Pressure Rocks From Northern Part Of Rio San Juan Complex, Dominican Republic, Khandaker I. Anam

FIU Electronic Theses and Dissertations

The Rio San Juan Complex is an important occurrence of high pressure/low temperature rocks in the circum-Caribbean region which contains both coherent blueschist units and two varieties of melange in the same area. The melanges contain a diverse assemblage of blocks of various sizes, different degrees of metamorphism, and mineral assemblages. Some high pressure blocks show two stages of metamorphism. The earliest stage is characterized by high pressure-low temperature conditions and the second stage is characterized by high pressure-lower temperature conditions. The geochemistry of thirteen samples from the Rio San Juan Complex has been studied and data have been compared …

An Experimental Petrologic And Geochemical Study Of Deccan Trap Basalts : Part I, Deccan Traps From Tamia, Central India ; Part Ii, Crystallization Relationships Of Deccan Basalts At 6.35 Kbars, Tobi Helene Cohen

FIU Electronic Theses and Dissertations

New major, minor, and trace element data for the Chakhla- Delakari sill and three nearby lava flows in the proximal area of Tamia are presented. Based on abundances of trace elements, it is inferred that the sill was the feeder of the two uppermost lava flows which tapped magmas from a LREE-, Rb-enriched source. The oldest (lowermost) flow shows greater affinity with the western Deccan lavas. The association of the feeder sill with a large network of parallel trending sills and dikes, and the elongate Satpura Dome, is taken to infer that a major locus of eruption of the Deccan …