Open Access. Powered by Scholars. Published by Universities.®

Geology Commons™

Open Access. Powered by Scholars. Published by Universities.®

University of South Florida

Discipline
Keyword
Publication Year
Publication
Publication Type
File Type

Articles 301 - 330 of 491

Full-Text Articles in Geology

Gypsum-Carbonate Speleothems From Cueva De Las Espadas (Naica Mine, Mexico): Mineralogy And Palaeohydrogeological Implications, Fernando Gázquez, Jose Maria Calaforra, Paolo Forti, Fernando Rull, Jesús Martínez-Frías Jan 2012

Gypsum-Carbonate Speleothems From Cueva De Las Espadas (Naica Mine, Mexico): Mineralogy And Palaeohydrogeological Implications, Fernando Gázquez, Jose Maria Calaforra, Paolo Forti, Fernando Rull, Jesús Martínez-Frías

International Journal of Speleology

Some of the most outstanding hypogenic gypsum speleothems worldwide have been recently discovered in the Naica mines. The Cueva de las Espadas (Swords Cave), which lies at 120 m depth, hosts a rare type of speleothem called “espada” (“sword”). This study contributes to the understanding of the mineralogical composition of these singular speleothems, by means of their examination using micro-Raman spectroscopy, FT-IR spectroscopy and EDX microprobe. Our data revealed a complex mineralogy comprising a high-purity selenite core covered by several layers of calcite, aragonite and gypsum. Solid inclusions of polymetallic oxides (Mn-Pb-Zn) and graphite were also detected. The position of …


2d And 3d Imaging Of The Metamorphic Carbonates At Omalos Plateau/Polje, Crete, Greece By Employing Independent And Joint Inversion On Resistivity And Seismic Data, Hamdan Ali Hamdan Dr, Nikos Economou, Giorgos Kritikakis, Nikos Andronikidis, Emmanuil Manoutsoglou, Antonis Vafidis, Pangratis Pangratis, Georgina Apostolidou Jan 2012

2d And 3d Imaging Of The Metamorphic Carbonates At Omalos Plateau/Polje, Crete, Greece By Employing Independent And Joint Inversion On Resistivity And Seismic Data, Hamdan Ali Hamdan Dr, Nikos Economou, Giorgos Kritikakis, Nikos Andronikidis, Emmanuil Manoutsoglou, Antonis Vafidis, Pangratis Pangratis, Georgina Apostolidou

International Journal of Speleology

A geophysical survey carried out at Omalos plateau in Chania, Western Crete, Greece employed seismic as well as electrical tomography methods in order to image karstic structures and the metamorphic carbonates (Tripali unit and Plattenkalk group) which are covered by post-Mesozoic deposits (terra rossa, clays, sands and gravels). The geoelectrical sections image the metamorphic carbonates which exhibit a highly irregular relief. At the central part of the plateau the thickness of post-Mesozoic deposits (terra rossa, clays, sands and gravels) ranges from 40-130 m. A 3D resistivity image was generated by inverting resistivity data collected on a grid to the south …


Diagenesis Of A Drapery Speleothem From Castañar Cave: From Dissolution To Dolomitization, Andrea Martín-Pérez, Rebeca Martín-García, Ana M. Alonso-Zarza Jan 2012

Diagenesis Of A Drapery Speleothem From Castañar Cave: From Dissolution To Dolomitization, Andrea Martín-Pérez, Rebeca Martín-García, Ana M. Alonso-Zarza

International Journal of Speleology

A drapery speleothem (DRA-1) from Castañar Cave in Spain was subjected to a detailed petrographical study in order to identify its primary and diagenetic features. The drapery’s present day characteristics are the result of the combined effects of the primary and diagenetic processes that DRA-1 underwent. Its primary minerals are calcite, aragonite and huntite. Calcite is the main constituent of the speleothem, whereas aragonite forms as frostwork over the calcite. Huntite is the main mineral of moonmilk which covers the tips of aragonite. These primary minerals have undergone a set of diagenetic processes, which include: 1) partial dissolution or corrosion …


Provenance And Geological Significance Of Red Mud And Other Clastic Sediments Of The Mugnano Cave (Montagnola Senese, Italy), Francesco Iacoviello, Ivan Martini Jan 2012

Provenance And Geological Significance Of Red Mud And Other Clastic Sediments Of The Mugnano Cave (Montagnola Senese, Italy), Francesco Iacoviello, Ivan Martini

International Journal of Speleology

The Mugnano cave is characterized by a thick clastic sedimentary fill showing a great variability of sedimentary facies, ranging from clay to coarse-grained sand deposits. This paper deals with combined sedimentological and mineralogical (XRD and SEM) studies of these sediments and bedrock insoluble residues in order to understand the origin and geological significance of cave deposits, with particular attention to red mud sediments, often considered as the residue of host rock dissolution. Three different sedimentary facies were recognized: i) YS, yellow sand with occasionally shell fragments, testifying the arrival of sediments from the surrounding landscape; ii) RS, red laminated mud; …


Petrographic And Isotopic Evidence For Late-Stage Processes In Sulfuric Acid Caves Of The Guadalupe Mountains, New Mexico, Usa, Margaret V. Palmer, Arthur N. Palmer Jan 2012

Petrographic And Isotopic Evidence For Late-Stage Processes In Sulfuric Acid Caves Of The Guadalupe Mountains, New Mexico, Usa, Margaret V. Palmer, Arthur N. Palmer

International Journal of Speleology

Caves of the Guadalupe Mountains have experienced many modifications since their final phase of sulfuric acid speleogenesis several million years ago. Petrographic and geochemical data reveal details of the change from H2SO4 to CO2-dominated reactions. The H2SO4 dissolution front acquired a coating of replacement gypsum with local pockets of anhydrite and by-products of altered clay, including Fe-Mn oxides. Alteration of bedrock beneath the gypsum produced a white micritized rind with small negative shifts in δ13C and δ18O. Solution basins contain records of the earliest post-speleogenetic processes: corroded bedrock, …


Natural And Anthropogenic Influences On The Morphodynamics Of Sandy And Mixed Sand And Gravel Beaches, Tiffany Roberts Jan 2012

Natural And Anthropogenic Influences On The Morphodynamics Of Sandy And Mixed Sand And Gravel Beaches, Tiffany Roberts

USF Tampa Graduate Theses and Dissertations

Beaches and coastal environments are dynamic, constantly shaped and reshaped by natural processes and anthropogenic modifications. The morphodynamics and influence of natural and anthropogenic factors of two different coasts at various temporal and spatial scales are discussed.

To quantify the performance of several beach nourishment projects at annual temporal and kilometer spatial scales on three adjacent microtidal low-wave energy barrier islands in west-central Florida, a total of 5,200 beach and nearshore-profiles spaced at 300 m were surveyed monthly to bi-monthly from 2006-2010. Beach nourishment performance is most significantly influenced by the interruption of longshore sediment transport by complex tidal-inlet processes. …


Shelf-Scale Mapping Of Fish Distribution Using Active And Passive Acoustics, Carrie Christy Wall Jan 2012

Shelf-Scale Mapping Of Fish Distribution Using Active And Passive Acoustics, Carrie Christy Wall

USF Tampa Graduate Theses and Dissertations

Fish sound production has been associated with courtship and spawning behavior. Acoustic recordings of fish sounds can be used to identify distribution and behavior. Passive acoustic monitoring (PAM) can record large amounts of acoustic data in a specific area for days to years. These data can be collected in remote locations under potentially unsafe seas throughout a 24-hour period providing datasets unattainable using observer-based methods. However, the instruments must withstand the caustic ocean environment and be retrieved to obtain the recorded data. This can prove difficult due to the risk of PAMs being lost, stolen or damaged, especially in highly …


Something Is Askew In Florida's Water: Arguing For A Better Descriptive Statistic For Positively Skewed Water-Quality Data, Amie October West Jan 2012

Something Is Askew In Florida's Water: Arguing For A Better Descriptive Statistic For Positively Skewed Water-Quality Data, Amie October West

USF Tampa Graduate Theses and Dissertations

ABSTRACT

It may be of no surprise that water quality data is right-skewed, but what appears to be overlooked by some is that the arithmetic mean and standard deviation most often fail as measures of central tendency in skewed data. When using the arithmetic mean and arithmetic standard deviation with nutrient data, one standard deviation about the arithmetic mean can capture nearly all of the data and extend into negative values. Representing nutrient data this way can be misleading to viewers who are using the statistics, and making assumptions, to understand the characteristics of those waters. Through an in-depth statistical …


Quasi 3-Dimensional Electrical Resistivity Mapping Of Air-Filled Karst Conduits And Policy Implications, Charles W. Mccrackin Oct 2011

Quasi 3-Dimensional Electrical Resistivity Mapping Of Air-Filled Karst Conduits And Policy Implications, Charles W. Mccrackin

USF Tampa Graduate Theses and Dissertations

This study assesses the capability and practical applications of quasi 3-Dimensional (3D) electrical resistivity surveying (ER) for mapping air-filled karst conduits. Vadose zone caves within the Brooksville Ridge of West Central Florida are relatively similar in architecture, with N-S elongation, and do not consist of an interconnected network of conduits. A high resolution quasi-3D ER survey was performed over two mapped cave systems on the Brooksville Ridge. The resultant survey verified the general effectiveness of quasi-3D ER in locating the two known near-surface cave features. Several other locations in the survey show similar or stronger resistivity anomalies trending in a …


Taxonomy And Geochemistry Of The Globigerinoides Ruber-Elongatus Plexus, With Paleontological Implications, Elizabeth Ann Brown Jul 2011

Taxonomy And Geochemistry Of The Globigerinoides Ruber-Elongatus Plexus, With Paleontological Implications, Elizabeth Ann Brown

USF Tampa Graduate Theses and Dissertations

The reliability of foraminifera as stratigraphic index fossils, and as isotopic proxies of marine environments, is based on the assumption that the fossil concepts represent uniform species, responding consistently to their ambient environments. Understanding sources of uncertainty is, therefore, critical. In this dissertation, I explore a potential bias in the application of planktonic foraminifera utilized extensively for Cenozoic paleo-reconstruction and, to a lesser extent, biostratigraphy: the Globigerinoides ruber-elongatus plexus (‘plexus’ meaning a complex network of interconnected members). Taxonomic revisions since 1826 have resulted in the merging of multiple Globigerinoides species names under one general designation (“Globigerinoides ruber”), the implications of …


Communications And 'Forestructures' At The Geological Intersection Of Caves And Subsurface Water Flow: Hermeneutics And Parochialism, Lee J. Florea, H. L. Vacher Jan 2011

Communications And 'Forestructures' At The Geological Intersection Of Caves And Subsurface Water Flow: Hermeneutics And Parochialism, Lee J. Florea, H. L. Vacher

Geology Faculty Publications

The direction of cave and karst science throughout its history has been partly determined by communication—or, more commonly, the lack of communication—between non-scientist cavers and non-caving physical geologists writing about karst. Within each community, advancement of ‘cave awareness’ occurred through a hermeneutic circle in which ‘forestructures’ guided progress. One result was regionalism of speleo-genetic theories developed within karst science because of the weight of evidence placed upon local or regional observations. Many speleogenetic theories of the mid-1900s suffer from this parochialism, failing to take into account findings from karst of different geologic settings. During the past half-century, the accumulated worldwide …


Proceedings Of The 2011 International Conference On Karst Hydrogeology And Ecosystems, Jason Samuel Polk, Leslie A. North Jan 2011

Proceedings Of The 2011 International Conference On Karst Hydrogeology And Ecosystems, Jason Samuel Polk, Leslie A. North

Environmental Sustainability Books

Jointly sponsored by the Hoffman Environmental Research Institute, the National Cave & Karst Research Institute, and the International Association of Hydrogeologists, the 2011 International Conference on Karst Hydrogeology and Ecosystems was held at Western Kentucky University in Bowling Green, Kentucy on 8-10 June 2011. Topics include karst geomorphology, engineering and modeling, isotope geochemistry, and cultural and educational aspects of karst environments.


A Sedimentary Record Of Regional Land-Use And Climate Change In The Manatee River, Manatee County, Florida, Patrick Schwing Jan 2011

A Sedimentary Record Of Regional Land-Use And Climate Change In The Manatee River, Manatee County, Florida, Patrick Schwing

USF Tampa Graduate Theses and Dissertations

The Manatee River Watershed (Manatee County, FL) has experienced heavy anthropogenic development over the last 100 years and was relatively pristine previous to this development. The population growth within the watershed has surpassed the national trends and has doubled in the last 30 years. The heavy anthropogenic development has led to depletion in natural resources, nutrient loading, coastal erosion, and increased pollution. This study constructs records of sedimentological processes to compare the pre-development records to the past 100 years of anthropogenic development. The first portion of this study identifies specific changes in sedimentation attributed to anthropogenic activity in the Manatee …


Late Cretaceous Faunal Dynamics In The Western Interior Seaway: The Record From The Red Bird Section, Eastern Wyoming, Joshua Stephen Slattery Jan 2011

Late Cretaceous Faunal Dynamics In The Western Interior Seaway: The Record From The Red Bird Section, Eastern Wyoming, Joshua Stephen Slattery

USF Tampa Graduate Theses and Dissertations

Studies examining bioevents (e.g., mass extinctions, faunal turnovers, diversification events) usually only scrutinize a short interval prior to such events, however, understanding their actual paleobiological implications requires a thorough understanding of the background conditions. The objective of this study is to document the background biodiversity dynamics in a single lithofacies of the Upper Cretaceous Pierre Shale that was deposited in an offshore setting of the Western Interior Seaway (WIS) and to place these changes into an environmental context. To assess the background biodiversity dynamics, the concretionary faunas of the Baculites eliasi through B. clinolobatus biozones of the Pierre Shale in …


Modeling Direct Runoff Hydrographs With The Surge Function, Denis Voytenko Jan 2011

Modeling Direct Runoff Hydrographs With The Surge Function, Denis Voytenko

USF Tampa Graduate Theses and Dissertations

A surge function is a mathematical function of the form f(x)=axpe-bx. We simplify the surge function by holding p constant at 1 and investigate the simplified form as a potential model to represent the full peak of a stream discharge hydrograph. The previously studied Weibull and gamma distributions are included for comparison. We develop an analysis algorithm which produces the best-fit parameters for every peak for each model function, and we process the data with a MATLAB script that uses spectral analysis to filter year-long, 15-minute, stream-discharge data sets. The filtering is necessary to locate the …


Alternative Statistical Methods For Analyzing Geological Phenomena: Bridging The Gap Between Scientific Disciplines, Joseph Frank Van Gaalen Jan 2011

Alternative Statistical Methods For Analyzing Geological Phenomena: Bridging The Gap Between Scientific Disciplines, Joseph Frank Van Gaalen

USF Tampa Graduate Theses and Dissertations

When we consider the nature of the scientific community in conjunction with a sense of typical economic circumstances we find that there are two distinct paths for development. One path involves hypothesis testing and evolution of strategies that are linked with iterations in equipment advances. A second, more complicated scenario, can involve external influences whether economic, political, or otherwise, such as the government closure of NASA's space program in 2011 which will no doubt influence research in associated fields. The following chapters are an account of examples of two statistical techniques and the importance of both on the two relatively …


Estimating Groundwater Discharge In The Oligohaline Ecotone Of The Everglades Using Temperature As A Tracer And Variable-Density Groundwater Models, Victora Spence Jan 2011

Estimating Groundwater Discharge In The Oligohaline Ecotone Of The Everglades Using Temperature As A Tracer And Variable-Density Groundwater Models, Victora Spence

USF Tampa Graduate Theses and Dissertations

Recent research suggests that brackish, marine-derived groundwater up-wells in the oligohaline ecotone of the coastal Everglades, bringing with it phosphorus to an otherwise phosphorus-poor environment. The purpose of this study is to estimate the rates and timing of the groundwater discharge by using variable-density groundwater models constructed, calibrated, and validated with field measurements of hydraulic head and surface and subsurface temperature. Modeled groundwater discharge rates ranged from 5.4E-04 mm/day in August to -1.3E-03 mm/day in June for Shark Slough and 4.8E-01 mm/day in June to -1.4E-01 mm/day in January for Taylor Slough, where positive values imply groundwater discharge and negative …


Secondary Halite Deposits In The Iranian Salt Karst: General Description And Origin, Michal Filippi, Jiří Bruthans, Lukáš Palatinus, Mohammad Zare, Naser Asadi Jan 2011

Secondary Halite Deposits In The Iranian Salt Karst: General Description And Origin, Michal Filippi, Jiří Bruthans, Lukáš Palatinus, Mohammad Zare, Naser Asadi

International Journal of Speleology

This paper summaries 12 years of documentation of secondary halite deposits in the Iranian salt karst.

A variety of secondary halite deposits was distinguished and classified into several groups, on the basis of the site and mechanism of their origin. Deposits formed: i) via crystallization in/on streams and pools, ii) from dripping, splashing and aerosol water, iii) from evaporation of seepage and capillary water, and iv) other types of deposits. The following examples of halite forms were distinguished in each of the above mentioned group: i) euhedral crystals, floating rafts (raft cones), thin brine surface crusts and films; ii) straw …


Mineralogy Of Iza Cave (Rodnei Mountains, N. Romania), Tudor Tămaş, Ferenc Kristály, Lucian Barbu-Tudoran Jan 2011

Mineralogy Of Iza Cave (Rodnei Mountains, N. Romania), Tudor Tămaş, Ferenc Kristály, Lucian Barbu-Tudoran

International Journal of Speleology

The secondary minerals from Iza Cave result from the interactions of karst water and/or cave atmosphere over a variety of sedimentary and metamorphic rocks. The cave passages expose at various extents Eocene limestones and conglomerates, Oligocene black shales, Upper Precambrian micaschists, marble and dolomitic marble and associated ore deposits.

Twelve secondary minerals identified in the cave (carbonates, sulfates, phosphates, oxides and hydroxides, and silicates) are presented in this study. Calcite, aragonite, gypsum, brushite and hydroxylapatite are the components of common speleothems in the limestone, dolomite and conglomerate areas of the cave. Ankerite crusts are related to areas with pyrite mineralization …


The First Cave Occurrence Of Orpiment (As₂S₃) From The Sulfuric Acid Caves Of Aghia Paraskevi (Kassandra Peninsula, N. Greece), Georgios Lazaridis, Vasilios Melfos, Lambrini Papadopoulou Jan 2011

The First Cave Occurrence Of Orpiment (As₂S₃) From The Sulfuric Acid Caves Of Aghia Paraskevi (Kassandra Peninsula, N. Greece), Georgios Lazaridis, Vasilios Melfos, Lambrini Papadopoulou

International Journal of Speleology

Orpiment, tamarugite and pickeringite occur in close association above the surface of thermal water cave pools in the active sulfuric acid caves of Aghia Paraskevi on the Kassandra peninsula, northern Greece. Gypsum also occurs as small interstitial crystals or encrustations. Orpiment is of high significance since it has not previously been reported as a cave mineral. In addition, tamarugite and pickeringite rarely occur in karst caves. Water from a borehole and a spring is of Na-Cl type and contains traces of CO2 and H2S. The B/Cl ratios indicate seawater participation with a possible mixing with geothermal water …


Trace Element And Stable Isotope Data From A Flowstone In A Natural Cave Of The Mining District Of Sw Sardinia (Italy): Evidence For Zn²⁺-Induced Aragonite Precipitation In Comparatively Wet Climatic Conditions, Guglielmo Angelo Caddeo, Jo De Waele, Franco Frau, Loren Bruce Railsback Jan 2011

Trace Element And Stable Isotope Data From A Flowstone In A Natural Cave Of The Mining District Of Sw Sardinia (Italy): Evidence For Zn²⁺-Induced Aragonite Precipitation In Comparatively Wet Climatic Conditions, Guglielmo Angelo Caddeo, Jo De Waele, Franco Frau, Loren Bruce Railsback

International Journal of Speleology

A speleothem from Crovassa Azzurra, a mine cave in SW Sardinia (Italy), has been analysed for mineralogy, minor and trace elements and stable isotopes. It is composed of layers of primary calcite and aragonite, with a region of secondary calcite. The primary carbonate is strikingly rich in Zn and Pb, presumably as the result of transport in solution from overlying Pb-Zn deposits. Immediately below the transition between calcite and aragonite, concentrations of Zn, Cd and P increase. At the transition between aragonite and Pb-rich aragonite, concentrations of Pb and P increase. Stable isotopes indicate an evolution toward more humid periods …


Minerals And Speleothems Of The József-Hegy Cave (Budapest, Hungary), Szabolcs Leél-Őssy, Gyöngyvér Szanyi, Gergely Surányi Jan 2011

Minerals And Speleothems Of The József-Hegy Cave (Budapest, Hungary), Szabolcs Leél-Őssy, Gyöngyvér Szanyi, Gergely Surányi

International Journal of Speleology

With the discovery of the József-hegy Cave, a cave of hydrothermal origin with an abundance of minerals unknown so far in Hungary came to light. Diversity and the frequency of the occurrence of crystals make this cave similar to the Lechuguilla Cave, even if the dimensions of the mineral precipitations and the passages do not compare in scale. The variety and mass of carbonates and sulphates are surprising. This paper describes the minerals and speleothems of the József-hegy Cave, their occurrence and genesis, including determined ages. The 41 U/Th measurements suggest that speleothems begun to develop in the upper level …


High-Resolution Event Stratigraphy Of Mm-Scale Laminated Sediments From Coastal Salt Ponds: St. John, Us Virgin Islands, Rebekka Amie Larson Jan 2011

High-Resolution Event Stratigraphy Of Mm-Scale Laminated Sediments From Coastal Salt Ponds: St. John, Us Virgin Islands, Rebekka Amie Larson

USF Tampa Graduate Theses and Dissertations

A multi-proxy approach is utilized on mm- to cm-scale laminated sediment records in coastal salt ponds on St. John, U.S. Virgin Islands to characterize the sediments, identify their sources and depositional processes/events (heavy rainfall, tropical cyclones, tsunamis). Historical records are combined with high-resolution geochronology (short-lived radioisotopes, 210Pb, 137Cs, 7Be) and scanning elemental techniques (XRF and LA-ICP-MS) to link depositional events to how they are manifested in the sedimentary record. Volcanic rocks are the terrigenous sediment source and the sedimentary signature of terrigenous sediment in the geologic record consists of higher amounts of Al, Fe, Ti, Co, and …


The Search For The Missing Mantles Of Differentiated Asteroids: Evidence From Taxonomic A-Class Asteroids And Olivine-Dominated Achondrite Meteorites, Michael Peter Lucas Jan 2011

The Search For The Missing Mantles Of Differentiated Asteroids: Evidence From Taxonomic A-Class Asteroids And Olivine-Dominated Achondrite Meteorites, Michael Peter Lucas

USF Tampa Graduate Theses and Dissertations

The apparent rarity of taxonomic A-class asteroids poses a significant paradox for understanding asteroid differentiation and the dynamical evolution of the early solar system. Based on results from asteroid taxonomic surveys, and on the abundances and mineralogy of different achondrite meteorites, it appears that olivine-dominated mantle remnants are missing from both the asteroid population and in meteorite collections. Several scenarios to explain this paradox have been proposed: (1) olivine mantle material has been stripped away by collisions and only remains as small fragments (< ~5 km), (2) A-class asteroids are abundant but have been altered in some way masking their presence, or (3) differentiated asteroids did not form thick olivine-rich mantles.

We have approached these questions through the collection of taxonomic and observational data on known A-class …


Impacts Of Artificial Reefs On Surrounding Ecosystems, Sarine Manoukian Jan 2011

Impacts Of Artificial Reefs On Surrounding Ecosystems, Sarine Manoukian

USF Tampa Graduate Theses and Dissertations

Artificial reefs are becoming a popular biological and management component in shallow water environments characterized by soft seabed, representing both important marine habitats and tools to manage coastal fisheries and resources. An artificial reef in the marine environment acts as an open system with exchange of material and energy, altering the physical and biological characteristics of the surrounding area. Reef stability will depend on the balance of scour, settlement, and burial resulting from ocean conditions over time. Because of the unstable nature of sediments, they require a detailed and systematic investigation.

Acoustic systems like high-frequency multibeam sonar are efficient tools …


Seasonal Changes In The Sinking Particulate Flux And In The Nitrogen Cycle Within The Euphotic And Twilight Zones Of The Cariaco Basin, Venezuela, Enrique Montes-Herrera Jan 2011

Seasonal Changes In The Sinking Particulate Flux And In The Nitrogen Cycle Within The Euphotic And Twilight Zones Of The Cariaco Basin, Venezuela, Enrique Montes-Herrera

USF Tampa Graduate Theses and Dissertations

This study explored the effects of seasonal variability on the geochemistry of sinking pthesiss and on the nitrogen cycle of the Cariaco Basin. Pthesis fluxes were measured at the base of the euphotic zone (the depth of 1% of photosynthetically active radiation - PAR) with drifting sediment traps during months of upwelling and non-upwelling regimes from March 2007 to November 2009. Flux estimates were analyzed in the context of seasonal variations in sea surface temperature, primary productivity, and chlorophyll a concentrations using data generated by the CARIACO Time-series Program as well as satellite data. Additionally, nine years (1996-2000 and 2004-2007) …


Stable Isotope Studies Of Paleoenvironment And Paleoclimate From Afar, Ethiopia, Zelalem K. Bedaso Jan 2011

Stable Isotope Studies Of Paleoenvironment And Paleoclimate From Afar, Ethiopia, Zelalem K. Bedaso

USF Tampa Graduate Theses and Dissertations

The sedimentary deposits of the Hadar Formation at Dikika and the Mount Galili Formation at Galili preserve a wealth of paleoenvironmental and paleoclimatic records spanning the last 5.29 Ma. Stable carbon and oxygen isotopic compositions of herbivore tooth enamel were analyzed for more than 600 specimens of 15 different taxa from 10 stratigraphic intervals. The application of carbon and oxygen isotopes here aims principally at reconstructing shifts in the relative abundance of C4 grasses, and its implications for climate indicators including temperature, aridity, and seasonality. The full range of δ13Cenamel values throughout the Plio-Pleistocene signifies a …


First Year Sedimentological Characteristics And Morphological Evolution Of An Artificial Berm At Fort Myers Beach, Florida, Katherine Brutsche Jan 2011

First Year Sedimentological Characteristics And Morphological Evolution Of An Artificial Berm At Fort Myers Beach, Florida, Katherine Brutsche

USF Tampa Graduate Theses and Dissertations

Dredging is often conducted to maintain authorized depths in coastal navigation channels. Placement of dredged sediment in the form of nearshore berms is becoming an increasingly popular option for disposal. Compared to direct beach placement, nearshore berms have fewer environmental impacts such as shore birds and turtle nesting, and have more lenient sediment compatibility restrictions. Understanding the potential morphological and sedimentological evolution is crucial to the design of a nearshore berm. Furthermore, the artificial perturbation generated by the berm installation provides a unique opportunity to understand the equilibrium process of coastal morphodynamics.

Matanzas Pass and Bowditch Point, located on the …


Initial Ablation Of The Laurentide Ice Sheet Based On Gulf Of Mexico Sediments, Elizabeth A. Brown Jan 2011

Initial Ablation Of The Laurentide Ice Sheet Based On Gulf Of Mexico Sediments, Elizabeth A. Brown

USF Tampa Graduate Theses and Dissertations

The objective of this project is to reconstruct a picture of initial Laurentide Ice Sheet retreat at the end of the Last Glacial Maximum (LGM) using geochemical proxies in Gulf of Mexico sediments, and place the reconstruction into global perspective. The project asks two questions. (1) Can a time frame be established for initial retreat of the Laurentide Ice Sheet? (2) If so, how does the timing compare to that of other large ice sheets and mountain glaciers in both hemispheres?

Sediment core MD02-2550 from the anoxic Orca Basin offers excellent preservation and a high sediment accumulation rate. Twelve accelerator …


Geochemical Systematics Among Amphibolitic Rocks In The Central Blue Ridge Province Of Southwestern North Carolina, Nathan Collins Jan 2011

Geochemical Systematics Among Amphibolitic Rocks In The Central Blue Ridge Province Of Southwestern North Carolina, Nathan Collins

USF Tampa Graduate Theses and Dissertations

The Central Blue Ridge sub-province of the southern Appalachian Mountains preserves an unique and complex geologic history. The Cartoogechaye terrane is the westernmost terrane of the Central Blue Ridge sub-province, and is characterized by extensive olistostromal sequences, including mafic-ultramafic massifs, isolated mafic units, and block-in-matrix structures of varying scales. This study investigates the genetic and tectonic relationships, and regional chemical and metamorphic trends of the amphibolitic rocks entrained within units of the Cartoogechaye and nearby terranes, toward constraining the origins of these regional sequences, and examining the rationale for the current Blue Ridge terrane designations.

A distinct compositional variation exists …