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2015

Geochemistry

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Full-Text Articles in Physical Sciences and Mathematics

Enriched Continental Flood Basalts From Depleted Mantle Melts: Modeling The Lithospheric Contamination Of Karoo Lavas From Antarctica, Jussi S. Heinonen, Arto V. Luttinen, Wendy A. Bohrson Dec 2015

Enriched Continental Flood Basalts From Depleted Mantle Melts: Modeling The Lithospheric Contamination Of Karoo Lavas From Antarctica, Jussi S. Heinonen, Arto V. Luttinen, Wendy A. Bohrson

All Faculty Scholarship for the College of the Sciences

Continental flood basalts (CFBs) represent large-scale melting events in the Earth’s upper mantle and show considerable geochemical heterogeneity that is typically linked to substantial contribution from underlying continental lithosphere. Large-scale partial melting of the cold subcontinental lithospheric mantle and the large amounts of crustal contamination suggested by traditional binary mixing or assimilation-fractional crystallization models are difficult to reconcile with the thermal and compositional characteristics of continental lithosphere, however. The well-exposed CFBs of Vestfjella, western Dronning Maud Land, Antarctica, belong to the Jurassic Karoo large igneous province and provide a prime locality to quantify mass contributions of lithospheric and sublithospheric sources …


Recent Discoveries In The Ni-Cu-Pge Bearing Trill And Parkin Offset Dykes, Sudbury Impact Structure, Canada, Adam B. Coulter Dec 2015

Recent Discoveries In The Ni-Cu-Pge Bearing Trill And Parkin Offset Dykes, Sudbury Impact Structure, Canada, Adam B. Coulter

Electronic Thesis and Dissertation Repository

The Sudbury structure hosts world class Ni-Cu-PGE deposits that have been mined, explored and studied for over 130 years. The structure is widely recognized as the erosional remnant of a 1.85 Ga 200- to 250-km tectonically altered multi-ring impact basin located in central Ontario, Canada. The focus of this investigation is on the Trill and Parkin Offset dykes. This study provides updated regional scale geologic maps, detailed geologic maps of newly exposed sections, geochemistry, sulphide analysis and an analysis of the inclusion population and orientation within the dykes. We conclude, the dyke phases display remarkable geochemical homogeneity, the Ni-Cu-PGE mineralization …


Thermodynamic Modeling Of Aqueous Geochemistry Of Chlorine Salts: Application To Stability And Habitability Of Liquid Brines On Mars, Amira Elsenousy Dec 2015

Thermodynamic Modeling Of Aqueous Geochemistry Of Chlorine Salts: Application To Stability And Habitability Of Liquid Brines On Mars, Amira Elsenousy

Graduate Theses and Dissertations

The WCL (Wet Chemistry Lab) instrument on board the Mars’s Phoenix Lander has identified the soluble ionic composition of the soil at the landing site. Two important ions were detected at the landing site; perchlorates (ClO4-) with a concentration of ~ 2.4 wt% and chlorides (Cl-) with a concentration of 0.54 wt%. Between chloride and perchlorate ions three other oxidized ions exist and called chlorine ions: hypochlorite ClO - (ox. state +1), chlorite ClO2- (ox. state +3) and chlorate ClO3- (ox. state +5). These oxidized ions might be existed as intermediate species on the surface of Mars but remained undetected. …


Exploring, Exploiting And Evolving Diversity Of Aquatic Ecosystem Models: A Community Perspective, Annette B.G. Janssen, George B. Arhonditsis, Arthur Beusen, Karsten Bolding, Louise Bruce, Jorn Bruggeman, Raoul-Marie Couture, Andrea S. Downing, J. Alex Elliott, Marieke A. Frassl, Gideon Gal, Daan J. Gerla, Matthew R. Hipsey, Fenjuan Hu, Stephen C. Ives, Jan H. Janse, Erik Jeppesen, Klaus D. Jöhnk, David Kneis, Xiangzhen Kong, Jan J. Kuiper, Moritz K. Lehmann, Carsten Lemmen, Deniz Özkundakci, Thomas Petzoldt, Karsten Rinke, Barbara J. Robson, René Sachse, Sebastiaan A. Schep, Martin Schmid, Huub Scholten, Sven Teurlincx, Dennis Trolle, Tineke A. Troost, Anne A. Van Dam, Luuk P.A. Van Gerven, Mariska Weijerman, Scott A. Wells, Wolf M. Mooij Dec 2015

Exploring, Exploiting And Evolving Diversity Of Aquatic Ecosystem Models: A Community Perspective, Annette B.G. Janssen, George B. Arhonditsis, Arthur Beusen, Karsten Bolding, Louise Bruce, Jorn Bruggeman, Raoul-Marie Couture, Andrea S. Downing, J. Alex Elliott, Marieke A. Frassl, Gideon Gal, Daan J. Gerla, Matthew R. Hipsey, Fenjuan Hu, Stephen C. Ives, Jan H. Janse, Erik Jeppesen, Klaus D. Jöhnk, David Kneis, Xiangzhen Kong, Jan J. Kuiper, Moritz K. Lehmann, Carsten Lemmen, Deniz Özkundakci, Thomas Petzoldt, Karsten Rinke, Barbara J. Robson, René Sachse, Sebastiaan A. Schep, Martin Schmid, Huub Scholten, Sven Teurlincx, Dennis Trolle, Tineke A. Troost, Anne A. Van Dam, Luuk P.A. Van Gerven, Mariska Weijerman, Scott A. Wells, Wolf M. Mooij

Civil and Environmental Engineering Faculty Publications and Presentations

Here, we present a community perspective on how to explore, exploit and evolve the diversity in aquatic ecosystem models. These models play an important role in understanding the functioning of aquatic ecosystems, filling in observation gaps and developing effective strategies for water quality management. In this spirit, numerous models have been developed since the 1970s. We set off to explore model diversity by making an inventory among 42 aquatic ecosystem modellers, by categorizing the resulting set of models and by analysing them for diversity. We then focus on how to exploit model diversity by comparing and combining different aspects of …


Predictive Modeling Of Terrestrial Radiation Exposure From Geologic Materials, Daniel A. Haber Dec 2015

Predictive Modeling Of Terrestrial Radiation Exposure From Geologic Materials, Daniel A. Haber

UNLV Theses, Dissertations, Professional Papers, and Capstones

Aerial gamma ray surveys are an important tool for national security, scientific, and industrial interests in determining locations of both anthropogenic and natural sources of radioactivity. There is a relationship between radioactivity and geology and in the past this relationship has been used to predict geology from an aerial survey. The purpose of this project

is to develop a method to predict the radiologic exposure rate of the geologic materials in an area by creating a model using geologic data, images from the Advanced Spaceborne Thermal Emission and Reflection Radiometer (ASTER), geochemical data, and pre-existing low spatial resolution aerial surveys …


8000 Years Of Environmental Evolution Of Barrier–Lagoon Systems Emplaced In Coastal Embayments (Nw Iberia), Rita González-Villanueva, Marta Pérez-Arlucea, Susana Costas, Roberto Bao, Xose L. Otero, Ronald J. Goble Nov 2015

8000 Years Of Environmental Evolution Of Barrier–Lagoon Systems Emplaced In Coastal Embayments (Nw Iberia), Rita González-Villanueva, Marta Pérez-Arlucea, Susana Costas, Roberto Bao, Xose L. Otero, Ronald J. Goble

Department of Earth and Atmospheric Sciences: Faculty Publications

The rocky and indented coast of NW Iberia is characterized by the presence of highly valuable and vulnerable, small and shallow barrier– lagoon systems structurally controlled. The case study was selected to analyse barrier–lagoon evolution based on detailed sedimentary architecture, chronology, geochemical and biological proxies. The main objective is to test the hypothesis of structural control and the significance at regional scale of any highenergy event recorded. This work is also aimed at identifying general patterns and conceptualizing the formation and evolution of this type of coastal systems. The results allowed us to establish a conceptual model of Holocene evolution …


Hornbrook Formation, Oregon And California: A Sedimentary Record Of The Late Cretaceous Sierran Magmatic Flare-Up Event, Kathleen D. Surpless Nov 2015

Hornbrook Formation, Oregon And California: A Sedimentary Record Of The Late Cretaceous Sierran Magmatic Flare-Up Event, Kathleen D. Surpless

Geosciences Faculty Research

Early Late Cretaceous time was characterized by a major magmatic flare-up event in the Sierra Nevada batholith and early phases of magmatism in the Idaho batholith, but the sedimentary record of this voluminous magmatism in the U.S. Cordillera is considerably less conspicuous. New detrital zircon U-Pb ages from the Hornbrook Formation in southern Oregon and northern California reveal a significant and sustained influx of 100–85 Ma detrital zircons into the broader Hornbrook region beginning ca. 90 Ma. Detrital zircon ages and hafnium isotopic compositions, combined with whole-rock geochemistry, suggest that sediment was largely derived from the Sierra Nevada, requiring uplift …


Interannual And Subdecadal Variability In The Nutrient Geochemistry Of The Cariaco Basin, Mary I. Scranton, Gordon T. Taylor, Robert Thunell, Claudia R. Benitez-Nelson, Frank Muller-Karger, Kent Fanning, Laura Lorenzoni, Enrique Montes, Ramon Varela, Yrene Astor Oct 2015

Interannual And Subdecadal Variability In The Nutrient Geochemistry Of The Cariaco Basin, Mary I. Scranton, Gordon T. Taylor, Robert Thunell, Claudia R. Benitez-Nelson, Frank Muller-Karger, Kent Fanning, Laura Lorenzoni, Enrique Montes, Ramon Varela, Yrene Astor

Faculty Publications

The CARIACO Ocean Time Series program has made monthly measurements of oxygen, nutrients, and carbon system parameters (∑CO2, alkalinity, pH) in the Cariaco Basin since 1996. At the same time, sediment traps have collected settling particles at four to five depths ranging from 150 to 1,200 m. The depth of the transition from oxic to anoxic conditions has fluctuated dramatically over the time series due to changes in the occurrence of Caribbean water intrusions into the deep basin. Nutrient concentrations in the deep basin have increased steadily with time in a proportion reflective of the elemental ratios in the settling …


Geochemical Evidence For An Eolian Sand Dam Across The North And South Platte Rivers In Nebraska, Daniel R. Muhs, James B. Swinehart, David B. Loope, Josh Been, Shannon A. Mahan, Charles A. Bush Aug 2015

Geochemical Evidence For An Eolian Sand Dam Across The North And South Platte Rivers In Nebraska, Daniel R. Muhs, James B. Swinehart, David B. Loope, Josh Been, Shannon A. Mahan, Charles A. Bush

David B. Loope

Geochemical and geomorphic data from dune fields in southwestern Nebraska provide new evidence that the Nebraska Sand Hills once migrated across the North and South Platte rivers and dammed the largest tributary system to the Missouri River. The Lincoln County and Imperial dune fields, which lie downwind of the South Platte River, have compositions intermediate between the Nebraska Sand Hills (quartz-rich) and northeastern Colorado dunes (K-feldspar-rich). The most likely explanation for the intermediate composition is that the Lincoln County and Imperial dunes are derived in part from the Nebraska Sand Hills and in part from the South Platte River. The …


Examination Of Banded Iron Formation Through Petrographic, Geochemical And Iron Isotope Analyses, Melissa Margaret Hage Aug 2015

Examination Of Banded Iron Formation Through Petrographic, Geochemical And Iron Isotope Analyses, Melissa Margaret Hage

Doctoral Dissertations

Banded iron formation (BIF) has the potential to preserve geochemical signatures critical to interpretation of early Earth because: (1) it is found within the Precambrian when fundamental changes in Earth’s physical, biological and chemical evolution occurred, and (2) it may preserve a record of the depositional environment. Rare earth elements (REE) are useful for investigating BIF because they have characteristic features. One goal of this study was to evaluate the calculation of certain REE ratios to determine if the calculation affected the interpretation. It was concluded that the method for calculating certain ratios may affect the interpretation of redox conditions …


Metal Mobilization In Groundwater, Bauxite, Ar, Steven Alexander Hamlin Jul 2015

Metal Mobilization In Groundwater, Bauxite, Ar, Steven Alexander Hamlin

Graduate Theses and Dissertations

The Wilcox Aquifer of Bauxite, AR contains bauxite ore deposits that may contribute heavy metals to groundwater. Twenty-four wells were sampled for aluminum, iron, manganese, zinc, lead, barium, nitrate, sulfate, sodium, alkalinity, calcium, magnesium, chloride, pH, total organic carbon, and total dissolved solids. A Wilcoxon Rank-Sum compared the similarity of the three geographic areas covered in the study. All parameters for wells in Bauxite and Sardis failed to reject the null hypothesis, signifying that wells all occupy the Saline Formation. 2/3rds of the parameters from BFI261 and the Bauxite region did not agree, suggesting the two areas do not occupy …


Hydrologic Controls Of Coastal Groundwater Discharge In Southern Taylor Slough, Everglades National Park, Florida, Edward Linden Jul 2015

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 …


Solving The Woolly Mammoth Conundrum: Amino Acid 15n-Enrichment Suggests A Distinct Forage Or Habitat, Rachel Schwartz-Narbonne, Fred J. Longstaffe, Jessica Z. Metcalfe, Grant Zazula Jun 2015

Solving The Woolly Mammoth Conundrum: Amino Acid 15n-Enrichment Suggests A Distinct Forage Or Habitat, Rachel Schwartz-Narbonne, Fred J. Longstaffe, Jessica Z. Metcalfe, Grant Zazula

Earth Sciences Publications

Understanding woolly mammoth ecology is key to understanding Pleistocene community dynamics and evaluating the roles of human hunting and climate change in late Quaternary megafaunal extinctions. Previous isotopic studies of mammoths’ diet and physiology have been hampered by the ‘mammoth conundrum’: woolly mammoths have anomalously high collagen δ15N values, which are more similar to coeval carnivores than herbivores, and which could imply a distinct diet and (or) habitat, or a physiological adaptation. We analyzed individual amino acids from collagen of adult woolly mammoths and coeval species, and discovered greater  15N enrichment in source amino acids of woolly …


Nwa 8614: The Least Heated Winonaite, Karla Farley, Alexander M. Ruzicka, Katherine Armstrong May 2015

Nwa 8614: The Least Heated Winonaite, Karla Farley, Alexander M. Ruzicka, Katherine Armstrong

Student Research Symposium

Northwest Africa 8614 is classified as a winonaite on the basis of oxygen isotope ratios, mineralogy, and highly reduced chemistry. Unlike other winonaites, it contains numerous and readily apparent chondrules. Here we discuss various features of NWA 8614 and the possible significance of the meteorite.

Petrological and chemical analyses were performed using optical microscopy with a DM2500 Leica petrographic microscope and a Zeiss Sigma VP-FEG scanning electron microscope (SEM) with a high-efficiency energy dispersive spectrometer (EDS). Oxygen isotopes were analyzed by Karen Ziegler at the University of New Mexico on acid-washed samples to remove terrestrial weathering products.

Owing to the …


Geochemical Analysis Of Surface Materials Surrounding The Bautsch-Gray Mine Superfund Site Near Galena, Illinois, Ryan Plath May 2015

Geochemical Analysis Of Surface Materials Surrounding The Bautsch-Gray Mine Superfund Site Near Galena, Illinois, Ryan Plath

Geology: Student Scholarship & Creative Works

The Bautsch-Gray zinc and lead mine, near Galena, IL, was in operation from the early 1900s until closing in 1975. The mine’s tailings pile has documented elevated lead and zinc concentrations in the surface materials surrounding the site. Numerous floods have caused contaminated sediment to migrate off the mine tailings pile, across Blackjack Road and into an outwash basin, and towards Smallpox Creek. Since this site was designated an EPA priority list Superfund site in 2010, the EPA has conducted numerous remediation efforts. This study attempts to develop a better understanding of the contamination within the soils of the outwash …


Sequence Stratigraphy, Depositional Environments And Geochemistry Of The Middle Cambrian Bloomington Formation In Northern Utah, Christopher Ryan Jensen May 2015

Sequence Stratigraphy, Depositional Environments And Geochemistry Of The Middle Cambrian Bloomington Formation In Northern Utah, Christopher Ryan Jensen

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

The Bloomington Formation (~425 m thick) is a latest Middle Cambrian (~506.5-505 Ma.), mixed warm water, carbonate and shale unit on the Cordilleran passive margin in northern Utah and southern Idaho. The Hodges Shale and Calls Fort Shale Members are shale dominated and the Middle Limestone Member is a thick carbonate. Fossil diversity and abundance is surprisingly low for a Middle Cambrian carbonate/shale formation. Present, however, are 10-50 cm thrombolite mud mounds, associated with Girvanella oncoliths. These mud mounds represent shallow water carbonates that experienced a small flooding event that gives the mud mounds time and proper conditions to build …


Paleoredox Geochemistry And Bioturbation Levels Of The Exceptionally Preserved Early Cambrian Indian Springs Biota, Poleta Formation, Nevada, Usa, Jonah Meron Novek May 2015

Paleoredox Geochemistry And Bioturbation Levels Of The Exceptionally Preserved Early Cambrian Indian Springs Biota, Poleta Formation, Nevada, Usa, Jonah Meron Novek

Theses and Dissertations

The early Cambrian Indian Springs biota, western Nevada, USA exhibits Burgess Shale-type (BST) preservation of a diverse array of animal phyla, including the earliest definitive echinoderms. It therefore provides an important window on animal life during the Cambrian radiation. The objective of this study is to analyze the trace metal paleoredox geochemistry and bioturbation levels of this BST deposit in order to characterize the paleoenvironmental conditions in which these animals lived and their fossils were preserved. A total of 28 rock samples were collected from outcrops at three previously reported intervals of exceptional preservation at the Indian Springs locality, as …


Modeling Background Radiation Using Geochemical Data, Kara Marsac May 2015

Modeling Background Radiation Using Geochemical Data, Kara Marsac

UNLV Theses, Dissertations, Professional Papers, and Capstones

Aerial gamma ray surveys have many applications in geology and science in general, such as locating mining prospects, defining radioactive plumes, and detecting nuclear weapons. Unfortunately there is currently no simple way to separate the natural gamma radiation of soil and rocks from that of contaminants such as radioactive plumes. This project used geochemical data (uranium, potassium and thorium concentrations) collected from national databases, private companies, and the NURE (National Uranium Resource Evaluation) Survey, to create forward models of exposure rates measured by aerial gamma ray surveys. We developed these techniques using an area in north central Arizona known as …


Effects Of Physical Characteristics Of Urban Storm Sewersheds On Water Quality In Bloomington, Il, Alicia Terese O'Hare Apr 2015

Effects Of Physical Characteristics Of Urban Storm Sewersheds On Water Quality In Bloomington, Il, Alicia Terese O'Hare

Theses and Dissertations

Increasing urbanization has consequences for surface water quality. Stormwater is a large component of urban water degradation that is poorly understood. Precipitation is quickly transported via underground pipes, from the land to the stream without following water's natural flow path. Studies have correlated detention ponds with improved water quality and impervious surface cover with degraded water quality. However, other physical characteristics within a storm sewer shed including the presence of sump pumps, area and pipe miles may also affect the stormwater quality. We chose 18 storm sewer systems in Bloomington, IL. We measured pH, temperature, conductivity, dissolved oxygen, chloride, nitrate, …


Hydroclimatic Shifts In Northeast Thailand During The Last Two Millennia — The Record Of Lake Pa Kho, Sakonvan Chawchai, Akkaneewut Chabangborn, Sherilyn C. Fritz, Minna Väliranta, Carl-Magnus Mörth, Maarten Blaauw, Paul J. Reimer, Paul J. Kusic, Ludvig Löwemark, Barbara Wohlfarth Mar 2015

Hydroclimatic Shifts In Northeast Thailand During The Last Two Millennia — The Record Of Lake Pa Kho, Sakonvan Chawchai, Akkaneewut Chabangborn, Sherilyn C. Fritz, Minna Väliranta, Carl-Magnus Mörth, Maarten Blaauw, Paul J. Reimer, Paul J. Kusic, Ludvig Löwemark, Barbara Wohlfarth

Department of Earth and Atmospheric Sciences: Faculty Publications

The Southeast Asian mainland is located in the central path of the Asian summer monsoon, a region where paleoclimatic data are still sparse. Here we present a multi-proxy (TOC, C/N, δ13C, biogenic silica, and XRF elemental data) study of a 1.5 m sediment/peat sequence from Lake Pa Kho, northeast Thailand, which is supported by 20 AMS 14C ages. Hydroclimatic reconstructions for Pa Kho suggest a strengthened summer monsoon between BC 170–AD 370, AD 800–960, and after AD 1450; and a weakening of the summer monsoon between AD 370–800, and AD 1300–1450. Increased run-off and a higher nutrient supply after AD …


Geochemistry Of Travertine Deposits In The Eastern Anatolia District: An Example Of The Karakoçan-Yoğunağaç (Elazığ) And Mazgirt-Dedebağ (Tunceli) Travertines, Turkey, Leyla Kalender, Özlem Özteki̇n Okan, Murat İnceöz, Bahatti̇n Çeti̇ndağ, Vesi̇le Yildirim Jan 2015

Geochemistry Of Travertine Deposits In The Eastern Anatolia District: An Example Of The Karakoçan-Yoğunağaç (Elazığ) And Mazgirt-Dedebağ (Tunceli) Travertines, Turkey, Leyla Kalender, Özlem Özteki̇n Okan, Murat İnceöz, Bahatti̇n Çeti̇ndağ, Vesi̇le Yildirim

Turkish Journal of Earth Sciences

The Karakoçan-Yoğunağaç (Elazığ) and Mazgirt-Dedebağ (Tunceli) travertines, which are related to thermal springs, are situated on the right-lateral strike-slip Karakoçan Fault Zone (KFZ) and left-lateral strike-slip Pamuklu Fault Zone (PFZ) in eastern Anatolia. The surface area of the travertines varies from m2 to km2. Morphologically, the travertines are classified as ridge, banded, and terrace types due to deposition in different ways, in the releasing/restraining bends of the KFZ and PFZ and on the segments of faults. The banded travertines were dated by U-series, and an age of 160,000 ± 76 years was determined in only one sample from the Mazgirt-Dedebağ …


Petrography And Geochemistry Of The Kamlial Formation, Southwestern Kohat Plateau, Pakistan: Implications For Paleoclimate Of The Western Himalayas, Kafayat Ullah, Mohammad Arif, Muhammad Tahir Shah Jan 2015

Petrography And Geochemistry Of The Kamlial Formation, Southwestern Kohat Plateau, Pakistan: Implications For Paleoclimate Of The Western Himalayas, Kafayat Ullah, Mohammad Arif, Muhammad Tahir Shah

Turkish Journal of Earth Sciences

The Middle to Late Miocene Kamlial Formation that largely consists of sandstone and interbedded clay/mudstone sequences is exposed in the southwestern part of the Kohat plateau, which constitutes the westernmost extension of the Himalayan Foreland Basin. Whereas the sandstone is gray to brownish gray, fine- to medium-grained, and mostly thick-bedded, the interbedded clay/mudstone sequence is brownish gray to maroon red and occurs as continuous beds as well as lenses. Some mudstone/clay beds are bioturbated and seem to be pedogenic surfaces. Results of geochemical investigation of fresh (unaltered) representative sandstone and mudstone samples from three different sections of the formation in …


Rare Earth Element Geochemistry Of The Upper Permian Limestone: The Kanigorgeh Mining District, Nw Iran, Ali Abedini, Ali Asghar Calagari Jan 2015

Rare Earth Element Geochemistry Of The Upper Permian Limestone: The Kanigorgeh Mining District, Nw Iran, Ali Abedini, Ali Asghar Calagari

Turkish Journal of Earth Sciences

The limestone of the Ruteh Formation of Upper Permian age in the Kanigorgeh district (northeast of Bukan, NW Iran) contains several layers and lenses of bauxitic ores. Mineralogical data show that this limestone consists of calcite and quartz as major and plagioclase, kaolinite, and hematite as minor mineral phases. Geochemical analyses reveal that the proportions of ?REEs (La-Lu) in this limestone vary from 35.28 to 160.78 ppm. The values of Eu and Ce anomalies (normalized to PAAS) of the limestone have ranges of 1.11-1.68 and 0.89-1.16, respectively. The high values of ?REEs; low values of Y/Ho; strong and positive correlations …


Rare Earth Element Patterns In Conodont Apatite From The Upper Ordovician: Testing Enrichment Sources And Possible Oceanographic Changes, Cody Christian Schulte Jan 2015

Rare Earth Element Patterns In Conodont Apatite From The Upper Ordovician: Testing Enrichment Sources And Possible Oceanographic Changes, Cody Christian Schulte

LSU Master's Theses

The Mohawkian series of the Middle Late Ordovician was a time of great lithological and faunal changes that coincide with a positive ä13C excursion known as the Guttenberg Isotopic Carbon Excursion (GICE). Two prevailing hypotheses have been proposed to explain the cause of these changes. The “cold-water” hypothesis suggests that global cooling caused the tropical belt to shrink and cold water to invade the epicontinental sea while the “tectonic-forcing” hypothesis suggests that increased weathering rates led to basinal deepening, resulting in cooler oceanic waters invading the midcontinent sea. This study tests if regional tectonics caused by the Taconic Orogeny led …


Tracing Sediment In The Subsurface Using Beryllium-7: Green River Basin, Ky, Caroline Adams Broderick Jan 2015

Tracing Sediment In The Subsurface Using Beryllium-7: Green River Basin, Ky, Caroline Adams Broderick

LSU Master's Theses

As water flows through areas of limestone, karst inevitably develops, creating sinking streams and sinkholes that transport alumino-silicate particles from the surface into the subsurface. Sediment budget studies on short term scales through karst are rare. Thus, a feasibility study using beryllium-7 (7Be), which attaches to soil particles and can be used as a short-term (2-3 month) tracer of the movement of fine-grained sediment in karst was investigated. Sediment samples were collected from a karstic catchment within Green River basin, Kentucky, both on the surface and in the subsurface along a cave stream. Samples were collected prior to and immediately …


The Champlain Sea/Lake Champlain Transition Recorded In The Northeast Arm Of Lake Champlain, Usa-Canada, Ashliegh Theresa Belrose Jan 2015

The Champlain Sea/Lake Champlain Transition Recorded In The Northeast Arm Of Lake Champlain, Usa-Canada, Ashliegh Theresa Belrose

Graduate College Dissertations and Theses

Sediment accumulated on a lakebed archives information about past climate and changes in the regional environment. Previous studies (Burgess, 2007; Koff, 2011; Palmer, 2012) in the Northeast Arm of Lake Champlain, specifically Missisquoi Bay and Saint Albans Bay, showed a period (~9,400 - 8,600 yBP) of elevated organic matter deposition in both bays, indicating a productive event that pre-dated any possible anthropogenic influence. However, the record was abruptly cut off and any documentation representing the span of time leading up to this event was not found. The elevated organic matter levels were explained as being the result of a warm, …


Augite In Komatiitic Basalts: A Study Of The Mobility Of Trace Elements During Rock Alteration, Alesha C. Morabito Jan 2015

Augite In Komatiitic Basalts: A Study Of The Mobility Of Trace Elements During Rock Alteration, Alesha C. Morabito

LSU Master's Theses

Komatiitic basalts are ultramafic rocks formed from volcanic liquids containing less than 18 wt.% magnesium oxide that can be linked, spatially, geochemically and texturally to komatiites. Archean komatiites and komatiitic basalts are critical to models of early Earth’s mantle evolution. Major and trace elements in these rocks are poorly preserved due to early sub-seafloor alteration with superimposed regional metamorphism: in particular the alkali, alkaline earths, and other elements with low valence numbers. Current analytical methods focus on analyzing whole rock, fresh olivines and melt inclusions to evaluate elemental concentrations and for petrogenetic studies. Although these methods establish elemental concentrations, REE, …


Interpretation Of Geochemical Signatures From Modern Carbonate Springs To The Rock Record, Benjamin Maas Jan 2015

Interpretation Of Geochemical Signatures From Modern Carbonate Springs To The Rock Record, Benjamin Maas

LSU Doctoral Dissertations

Despite the importance of carbonate aquifers as reservoirs of oil, of water, and of carbon dioxide, questions remain about the diagenetic processes that enhance porosity and permeability. Some of the questions are: 1) what are the water-rock interactions that control the geochemistry of spring waters; 2) are the geochemical signatures of saline-fresh water mixing zones preserved in the carbonate rock record; and 3) how much carbon dioxide outgases along spring runs? To address these questions, two field sites, one in Oklahoma (the site of an active saline-fresh water mixing zone) and the other in Colorado, the location of a former …


Accelerated Degradation Of Chlorinated Solvents By Copper-Modified Nanoscale Zero Valent Iron (Cu-Nzvi) Stabilized With Carboxymethyl Cellulose, Andrew Franze Jan 2015

Accelerated Degradation Of Chlorinated Solvents By Copper-Modified Nanoscale Zero Valent Iron (Cu-Nzvi) Stabilized With Carboxymethyl Cellulose, Andrew Franze

Browse all Theses and Dissertations

Nanoscale zero valent iron (nZVI) is a remediation technology that can be used to treat chlorinated hydrocarbons (CHCs) in contaminated aquifers. Nanoparticles remain mobile in water and can be transported with groundwater flow to contaminated zones. However, due to magnetic and van der Waals forces, unstabilized nZVI agglomerates. Carboxymethylcellulose (CMC) was used as a polyelectrolyte stabilizer in this study. nZVI serves as an electron donor and can dechlorinate CHCs. nZVI reactivity with CHCs can be enhanced by addition of a secondary metal catalyst. This study evaluates the potential of copper amended nZVI (Cu-nZVI) to degrade select CHCs. The objective of …