Geochemistry Commons^™

Unusual Internal Structure Of Cm-Sized Coldwater Calcite: Weichselian Spars In Former Pools Of The Zinnbergschacht Cave (Franconian Alb/Se Germany), Detlev K. Richter, Rolf D. Neuser, Martin Harder, Hardy Schabdach, Denis Scholz

International Journal of Speleology

The investigation of the internal structure of calcite crystals is a new focus in speleothem science, especially in the range of crystallization temperatures close to 0°C. Recently found calcite spars from Zinnbergschacht Cave of the Franconian Alb (SE Germany) are ideal for multi-method investigation. The elongated calcites (up to 6 cm in length) with three to six lateral faces and basal triangular faces at the ends are observed in collapse-zones in the cave. ²³⁰Th/U-ages of 38.9 ka suggest formation during the periglacial Weichselian, between the Scandinavian and Alpine Glaciations. The δ¹⁸O and δ¹³C values of …

Iodine To Calcium Ratios In Marine Carbonates As An Indicator Of Oxygen Levels, Angela Stahl

Senior Honors Projects

ANGELA STAHL (Marine Biology)

Iodine to Calcium Ratios in Marine Carbonates as an Indicator of Oxygen Levels

Sponsor: Rebecca Robinson (Graduate School of Oceanography)

The Earth goes through natural cycles of warm and cool periods. In the past,

warmer oceans during interglacial periods have been shown to hold less oxygen

in their waters compared to cooler, glacial oceans. For this research, we are

studying an area in the Eastern Tropical Pacific where it is known to have

variable concentrations of dissolved oxygen in the waters due to the influence of

the climate. Oxygen is a vital component for most organisms …

Carbon Flux And Weathering Processes In Icelandic Glacial-Fed Rivers, Allison Quiroga

Masters Theses & Specialist Projects

An investigation into the carbon dynamics and weathering processes occurring in Icelandic glacial-fed streams was conducted during the spring to summer seasonal transition in June of 2017. Four major outlet rives were sampled from the glaciers of Gígjökull, Steinsholtsjökull, Sólheimajökull, and Falljökull. Markarfljót, the major river that Gígjökull, Steinsholtsjökull, and many other glaciers drain into, was also sampled. Longitudinal sampling occurred at all sites to capture downstream trends in the hydrogeochemistry and carbon dynamics. Distinct differences in geochemistry between glacier surface meltwater, sub-glacial waters, pro-glacial lake water, and post-mixed downstream samples were evident in the data. Glacier surface streams were …

Geochemical And Petrological Investigation Of The Prospective Ni-Cu-Pge Mineralization At The Echo Lake Intrusion In The Upper Peninsula Of Michigan, Usa, Alexander J. Koerber

Masters Theses

The Echo Lake Intrusion is located in Houghton and Ontonagon counties in the Upper Peninsula (UP) of Michigan. The intrusion is approximately 200 m below the surface and covers approximately 18 km2 in lateral extent. It is associated with the magmatic activities of a 1.1 Ga geologic event called the Midcontinent Rift. The rift is responsible for the formation of Ni-Cu ± PGE deposits in the Lake Superior Region. Based on its association with the Midcontinent Rift and a Cu and PGE enriched layer, the Echo Lake intrusion is identified as a prospect for an economic magmatic sulfide deposit.

The …

Production And Composition Of Pyrogenic Dissolved Organic Matter From A Logical Series Of Laboratory-Generated Chars, Kyle W. Bostick, Andrew R. Zimmerman, Andrew S. Wozniak, Siddhartha Mitra, Patrick G. Hatcher

Chemistry & Biochemistry Faculty Publications

Though pyrogenic carbon (pyC) has been assumed to be predominantly stable, degradation and transfers of pyC between various pools have been found to influence its cycling and longevity in the environment. Dissolution via leaching may be the main control on loss processes such as microbial or abiotic oxidation, mineral sorption, or export to aquatic systems. Yet, little is known about the controls on pyrogenic dissolved organic matter (pyDOM) generation or composition. Here, the yield and composition of pyDOM generated through batch leaching of a thermal series of oak and grass biochars, as well as several non-pyrogenic reference materials, was compared …

Geochemical Modeling Of Primary Morb Magmas: Implications For Parental Melting Regimes In Melt Lenses Along-Axis Of The Hess Deep Rift, Stephanie Michelle Drumm

USF Tampa Graduate Theses and Dissertations

The Hess Deep Rift in the East Pacific Rise is a mid-ocean ridge spreading center that produces melts which exhibit geochemical characteristics of evolved MORB. Using basaltic glass samples collected from multiple dive cruises that explored Hess Deep geology, volatile and chemical data were collected at USF using FTIR and EMPA, respectively. In addition, a data suite of samples of glass from Hess Deep were compiled from the EarthChem database. The intention was to use the data suite and models to compare the Hess Deep regime to analog models for mid-ocean ridge crystallization regimes and tectonic structures. The USF and …

Signal Propagation, Provenance, And Climate Records In The Indus Submarine Canyon Since The Last Deglacial, Yuting Li

LSU Doctoral Dissertations

The Monsoon is one of the most powerful climatic phenomena on Earth and controls environments in South Asia. Erosion and weathering patterns are influenced by monsoon variations and can be reconstructed through marine sediment records. However, such reconstruction is based on the assumption that such sediments are representative of the onshore basins from which they are sourced. Debate continues regarding the degree to which storage and recycling homogenize short-term variations in sediment compositions. The Indus Submarine Canyon links the river mouth and the deep-water fan of the Indus drainage system. Determining how sediment fluxes through this canyon is important if …

Landscapes From The Waves—Marine Terraces Of California, Marjorie Schulz, Corey Lawrence, Daniel R. Muhs, Carol Prentice, Sam Flanagan

United States Geological Survey: Publications

M any coastlines around the world have stair-step landforms, known as marine terraces. Marine terraces make up a large part of coastal California’s landscape—from San Diego to Crescent City. Find out how these landscapes form, why marine terraces are of interest to scientists, and where you can explore these landscapes.

Marine terraces result from the interaction of two geologic processes: uplift of the land surface and the natural rise and fall of sea level over hundreds of thousands of years. As sea level rises, waves move underwater sediment—sand and gravel—back and forth against bedrock, acting like sandpaper to hone bedrock …

Nutrient Export From A Proximal Intermittent Stream Draining Eku Meadowbrook Farm, Madison County, Kentucky, James Scott Winter, Walter S. Borowski, Jonathan M. Malzone

EKU Faculty and Staff Scholarship

Agricultural activities contribute significant amounts of nutrients that contaminate surface and subsurface water. Eastern Kentucky University (EKU) Meadowbrook Farm (Madison County, Kentucky) seeks to decrease its export of nutrients to Muddy Creek using sequestration techniques. The first step in the overall process is to determine nutrient export at present, before sequestration efforts take place. Here we estimate the export of phosphate, nitrate, and ammonium during Tropical Storm Cindy (July 22 to 24, 2017) from a proximal, intermittent stream, named the BRC. This stream drains a representative portion the Farm, receiving water from a dairy complex, pasture, and cropland.

To estimate …

Characterization Of Groundwater And Surface Water Geochemistry In An Agricultural Setting At Eku Meadowbrook Farm, Madison County, Kentucky, Reid E. Buskirk, Walter S. Borowski, Jonathan M. Malzone

EKU Faculty and Staff Scholarship

Agricultural activities often contaminate watersheds with excess nutrients leading to poor water quality and eutrophication. Eastern Kentucky University (EKU) Meadowbrook Farm raises crops and livestock, which contribute dissolved nutrients to the neighboring Muddy Creek watershed. Consequently, the Farm is developing methods to sequester phosphorous and limit nutrient contamination.

Before phosphorous sequestration methods can be tested, Farm surface water and groundwater geochemistry must be better understood to determine hydrological pathways for nutrients. We use naturally-occurring dissolved cations, pH, oxidation-reduction potential (ORP), specific conductivity (SC), dissolved oxygen (DO%), total hardness, and alkalinity as chemical tracers to parse the contribution of dissolved ions …

Global Seawater Redox Trends During The Late Devonian Mass Extinction Detected Using U Isotopes Of Marine Carbonates, David Allen White

Earth and Planetary Sciences ETDs

The Late Devonian extinction ranks as one of the ‘big five’ Phanerozoic extinctions affecting up to 80% of marine species and occurred during five distinct pulses spanning /or widespread marine anoxia. We test the marine anoxia hypothesis by analyzing uranium isotopes (δ²³⁸U) across a ~7 My interval of well-dated Upper Devonian marine carbonates from the Devil’s Gate Limestone in Nevada, USA.

The measured δ²³⁸U curve shows no co-variation with local anoxic facies, water-depth dependent facies changes, redox-sensitive metals, TOC, or diagnostic elemental ratios indicating the δ²³⁸U curve was not controlled by local depositional or …

Effects Of Elevated Co2, Increased Nitrogen Deposition, And Plant Diversity On Aboveground Litter And Root Decomposition, Xiaoan Zuo, Johannes Knops

School of Biological Sciences: Faculty Publications

Global change-induced litter decomposition strongly affects the carbon (C) and nitrogen (N) dynamics in grassland ecosystems. However, few studies show the interactive effects of global change factors on litter and root decomposition. We conducted a four-year grassland field experiment to examine the quality and decomposition of litter and root in a three-factorial experiment with elevated CO₂, increased N deposition, and plant species richness. We found that elevated CO₂ decreased the litter N content and root lignin content. N addition increased the root N content and decreased the litter lignin content. Increasing plant richness decreased the N and …

Nitrogen Isotopes Suggest A Change In Nitrogen Dynamics Between The Late Pleistocene And Modern Time In Yukon, Canada, Farnoush Tahmasebi, Fred J. Longstaffe, Grant Zazula

Earth Sciences Publications

A magnificent repository of Late Pleistocene terrestrial megafauna fossils is contained in ice-rich loess deposits of Alaska and Yukon, collectively eastern Beringia. The stable carbon (δ¹³C) and nitrogen (δ¹⁵N) isotope compositions of bone collagen from these fossils are routinely used to determine paleodiet and reconstruct the paleoecosystem. This approach requires consideration of changes in C- and N-isotope dynamics over time and their effects on the terrestrial vegetation isotopic baseline. To test for such changes between the Late Pleistocene and modern time, we compared δ¹³C and δ¹⁵N for vegetation and bone …

An Overview Of Anorthosite-Bearing Layered Intrusions In The Archaean Craton Of Southern West Greenland And The Superior Province Of Canada: Implications For Archaean Tectonics And The Origin Of Megacrystic Plagioclase, Ali Polat, Fred J. Longstaffe, Robert Frei

Earth Sciences Publications

Anorthosite-bearing layered intrusions are unique to the Archaean rock record and are abundant in the Archaean craton of southern West Greenland and the Superior Province of Canada. These layered intrusions consist mainly of ultramafic rocks, gabbros, leucogabbros and anorthosites, and typically contain high-Ca (>An₇₀) megacrystic (2–30 cm in diameter) plagioclase in anorthosite and leucogabbro units. They are spatially and temporally associated with basalt-dominated greenstone belts and are intruded by syn-to post-tectonic granitoid rocks. The layered intrusions, greenstone belts and granitoids all share the geochemical characteristics of Phanerozoic subduction zone magmas, suggesting that they formed mainly in a …

Petrogenetic And Geodynamic Origin Of The Neoarchean Doré Lake Complex, Abitibi Subprovince, Superior Province, Canada, Ali Polat, Robert Frei, Fred J. Longstaffe, Ryan Woods

Earth Sciences Publications

The Neoarchean (ca. 2728 Ma) anorthosite-bearing Doré Lake Complex in the northeastern Abitibi subprovince, Quebec, was emplaced into an association of intra-oceanic tholeiitic basalts and gabbros known as the Obatogamau Formation. The Obatogamau Formation constitutes the lower part of the Roy Group, which is composed of two cycles of tholeiitic-to-calc-alkaline volcanic and volcaniclastic rocks, siliciclastic and chemical sedimentary rocks, and layered mafic-to-ultramafic sills. In this study, we report major and trace element results, and Nd, Sr, Pb and O isotope data for anorthosites, leucogabbros, gabbros and mafic dykes from the Doré Lake Complex and spatially associated basalts and gabbros of …

Petrology And Geochemistry Of The Tasse Mantle Xenoliths Of The Canadian Cordillera: A Record Of Archean To Quaternary Mantle Growth, Metasomatism, Removal, And Melting, Ali Polat, Robert Frei, Fred J. Longstaffe, Derek J. Thorkelson, Eyal Friedman

Earth Sciences Publications

Mantle xenoliths hosted by the Quaternary Tasse alkaline basalts in the Canadian Cordillera, southeastern British Columbia, are mostly spinel lherzolite originating from subcontinental lithospheric mantle. The xenoliths contain abundant feldspar veins, melt pockets and spongy clinopyroxene, recording extensive alkaline metasomatism and partial melting. Feldspar occurs as veins and interstitial crystal in melt pockets. Melt pockets occur mainly at triple junctions, along grain boundaries, and consist mainly of olivine, cpx, opx and spinel surrounded by interstitial feldspar. The Nd, Sr and Pb isotopic compositions of the xenoliths indicate that their sources are characterized by variable mixtures of depleted MORB mantle and …

The Pothole Hydrology-Linked Systems Simulator (Phyliss)—Development And Application Of A Systems Model For Prairie-Pothole Wetlands, Owen P. Mckenna, David M. Mushet, Eric J. Scherff, Kyle I. Mclean, Christopher T. Mills

United States Geological Survey: Publications

The North American Prairie Pothole Region covers about 770,000 square kilometers of the United States and Canada (including parts of 5 States and 3 provinces: North Dakota, South Dakota, Montana, Minnesota, Iowa, Saskatchewan, Manitoba, and Alberta). The Laurentide Ice Sheet shaped the landscape of the region about 12,000 to 14,000 years ago. The retreat of the ice sheet left behind low-permeability glacial till and a landscape dotted with millions of depressions known today as prairie potholes. The wetlands that subsequently formed in these depressions, prairie-pothole wetlands, provide critical migratory-bird habitat and support dynamic aquatic communities. Extensive grasslands and productive agricultural …

Appendix 1. Testing The Influence Of Management Regime And Year On Vegetation Structure Variables On Two Grass Types On Federal Lands Managed Under An Adaptive-Management Framework By The U.S. Fish And Wildlife Service In North Dakota, South Dakota, Minnesota, And Montana, 2011–13, J.J Gannon, T.L. Shaffer, C.T. Moore

United States Geological Survey: Publications

Generalized linear mixed model (assuming a beta distribution with a logit link) testing the influence of management regime and year on mean bare-ground cover (percent) on two grass types on Federal lands managed under an adaptive-management framework by the U.S. Fish and Wildlife Service (Gannon and others, 2013) in North Dakota, South Dakota, Minnesota, and Montana, 2011–13.

Environmental Forensics Study Of Crude Oil And Petroleum Product Spills In Coastal And Oilfield Settings: Combined Insights From Conventional Gc-Ms, Thermodesorption-Gc-Ms And Pyrolysis-Gc-Ms, Michael A. Kruge, José Luis Gallego, Azucena Lara-Gonzalo, Noemi Esquinas

Department of Earth and Environmental Studies Faculty Scholarship and Creative Works

A representative set of five oil spill samples from four different regions displayed different product characteristics and different levels of weathering. Three of them were taken along shorelines affected by marine oil spill events, viz., Aboño and Prestige (Spain) and Deepwater Horizon (USA) and the other two were taken at inland oil spill sites (Angola and Kuwait). A multi-faceted environmental forensics approach revealed key molecular features. In addition to the conventional GC/MS analysis of saturated and aromatic fractions, the polar fractions also were analyzed, revealing a complex series of linear alkanones in those oil samples particularly enriched in aliphatics. Thermodesorption-GC-MS …

Trace Element And Isotopic Fingerprinting Of Olivine Phenocrysts As Recorders Of Magmatic Processes In The Golden Trout Volcanic Field, Kern Plateau, Ca, Mark E. Szymanski

Cal Poly Humboldt theses and projects

Quaternary mafic volcanism in the western Basin and Range and in the southeastern Sierra Nevada is largely controlled by extensional stresses that promote magma generation through decompression melting of the lithospheric and asthenospheric mantle. Where volcanism occurs in the Sierra Nevada, like at the Golden Trout Volcanic Field GTVF), the eruption rate, number of vents, and eruption volume is an order of magnitude less than at neighboring Basin and Range volcanic fields such as the Big Pine Volcanic Field (BPVF). To determine the factors that cause these differences in adjacent and contemporaneous volcanic fields, I sampled rocks from both fields …

Stable Bromine Isotope Signature Of Bromoform From Enzymatic And Abiotic Formation Pathways And Its Application In Identifying Sources Of Environmental Bromoform In The Damariscotta River, Chengyang Wang

Honors Theses

Bromoform is a major source of atmospheric bromine. Most bromoform is produced by marine organisms including macroalgae and phytoplankton, using the enzyme bromoperoxidase (BPO). Bromoform can also be a byproduct of industrial processes such as water disinfection. Identifying sources of environmental bromoform is still a challenge. A novel technique of using quadrupole mass spectrometry coupled to a gas chromatography (GCqMS) was developed and optimized for Br isotope analyses. The study shows that GCqMS in single ion monitoring (SIM) mode can measure 81Br with precision of around ±0.7‰ (60pmol bromoform injected). This study aims to investigate stable Br isotopes of bromoform …

Evidence For Ephemeral Middle Eocene To Early Oligocene Greenland Glacial Ice And Pan-Arctic Sea Ice, Aradhna Tripati, Dennis Darby

OES Faculty Publications

Earth's modern climate is defined by the presence of ice at both poles, but that ice is now disappearing. Therefore understanding the origin and causes of polar ice stability is more critical than ever. Here we provide novel geochemical data that constrain past dynamics of glacial ice on Greenland and Arctic sea ice. Based on accurate source determinations of individual ice-rafted Fe-oxide grains, we find evidence for episodic glaciation of distinct source regions on Greenland as far-ranging as ~68°N and ~80°N synchronous with ice-rafting from circum-Arctic sources, beginning in the middle Eocene. Glacial intervals broadly coincide with reduced CO_{2 …}

Giant Plagioclase In The Steens Basalt, Se Oregon: Cumulate Entrainment Revealed By Textural And In Situ Chemical Analysis, Conner H. Toth

All Master's Theses

Many of the lava flows comprising the Steens Basalt in SE Oregon, the oldest and most mafic formation of the Columbia River Basalt Group (CRBG), contain exceptionally large (up to 5 cm) and abundant (up to 40 modal %) plagioclase crystals. This thesis presents a model for giant plagioclase formation in a complex system that integrates petrographic and in situ plagioclase compositional analyses with whole-rock data and computational modeling to explain systematic textural and chemical differences between plagioclase of the lower and upper Steens Basalt sub-sections. Lower Steens plagioclase are typically more chemically homogenous than upper Steens plagioclase and exhibit …

The Origin Of Dark Mats At The Sunrise Ridge Borrow Pit Site (45pi408) Mount Rainier National Park, Washington, Sean Stcherbinine

All Master's Theses

The Sunrise Ridge Borrow Pit Site is a precontact archaeological site located in the upland forest soils of Mount Rainier National Park. Site stratigraphy is complicated, consisting of tephra deposits from mostly known origins that are intercalated with dark sediments of unknown origin, referred to here as dark mats. Precontact occupation has been split previously into two components based on the ambiguous depositional history of the dark mats, notably their unknown parent material, depositional environment, and relationship with adjacent tephra strata. Stratigraphic samples from excavation units, features, and one off-site excavation unit was used to investigate these data gaps. Grain …

Assessing The Impact Of The Conservation Reserve Program On Honey Bee Health, Otto, C.R.V., O'Dell, S., Bryant, R.B., Euliss, N.H., Bush

United States Geological Survey: Publications

Insect pollinators are critically important for maintaining U.S. food production and ecosystem health. The upper Midwest is home to more than 40 percent of all U.S. honey bee colonies and is considered by many beekeepers to be America’s last beekeeping refuge. Beekeepers come to this region because their honey bees require high-quality grassland and bee-friendly agricultural crops to make honey and to improve bee health. Agricultural grassland, such as those enrolled in the Conservation Reserve Program (CRP), support flowers that provide bees with the pollen and nectar they need. In 2014, the U.S. Department of Agriculture (USDA) and the U.S. …

Adaptive Management In Native Grasslands Managed By The U.S. Fish And Wildlife Service—Implications For Grassland Birds, Lawrence D. Igl, Welsey E. Newton, Todd A. Grant, Cami S. Dixon

United States Geological Survey: Publications

Burning and grazing are natural processes in native prairies that also serve as important tools in grassland management to conserve plant diversity, to limit encroachment of woody and invasive plants, and to maintain or improve prairies. Native prairies managed by the U.S. Fish and Wildlife Service (FWS) in the Prairie Pothole Region of the northern Great Plains have been extensively invaded by nonnative, cool-season species of grasses. These invasions were believed to reflect a common management history of long-term rest and little or no defoliation by natural processes (burning and grazing). To address the challenges associated with these invasive species, …

Geostatistical And Geospatial Distribution Of Multiple Metallic Elements In Agricultural Regions Of The Mid-Continental Usa, Najwah Alssaeidi Ahmed Almesleh

Open Access Theses & Dissertations

Regional geochemical mapping constitute the chemistry of the surface of the earth in a large scale and relatively low sample density. It is widely accepted scientific activity and man uses some cases to identify contamination. In the present study, data present in national geochemical survey database was used to investigate the chemical loading loading of the agricultural soil. In the mid-continent region of the United States. Several traditional parameters were used mainly the enrichment factor (EF), and geoaccumulation index (I geo). Total chemical influence (TCI) maps were used to guide sampling. In addition, regional trace element chemistry of bedrock was …

Stratigraphy And Organic Geochemistry Reveal Patterns Of Late Quaternary Paleo-Productivity At Mono Lake, California, Bailee Nicole Hodelka

Theses and Dissertations--Earth and Environmental Sciences

Mono Lake (CA) is a hydrologically closed lacustrine basin well-known for its paleo-shorelines, which record fluctuations in water level for the last deglacial and late Holocene. Mono Lake is a sentinel of California’s water supply, situated in the rain shadow of the Sierra Nevada, a mountain range whose snowpack is a vital source of freshwater for urban and agricultural districts to the west and south. Recent droughts, floods, and wildfires show that California is threatened by climate change, but how these changes impact and get recorded by Mono Lake sediments remains poorly known. Here, we use a new radiocarbon-dated deepwater …

A Multi-Indicator Approach To Understanding The Diagenesis Of Carbonates In Pennsylvanian Mudrocks Of The Midland Basin, Alex J. Reis

Theses and Dissertations--Earth and Environmental Sciences

The Late Pennsylvanian was a time of frequent, rapid glacioeustatic sea-level changes. These changes were recorded in the Wolfcamp D Formation of the Midland Basin as a series of cyclothems similar to those studied in the Midcontinent region (e.g., Algeo and Heckel, 2008). This study focuses on identifying the mechanisms and controls on carbonate deposition and diagenesis through the Upper Pennsylvanian Wolfcamp D Formation and evaluating the potential for these layers to be stratigraphically significant. A stepwise progression of diagenetic processes was identified through the use of δ¹³C_carb and δ¹⁸O_carb, bulk geochemical and …

Abandoned Mine Land Impacts On Tributaries In The Upper Yakima River Watershed, Eastern Cascades, Washington, Scott Kugel

All Master's Theses

Effluent from abandoned mine lands (AMLs) in several drainages in Washington’s Eastern Cascades flows into the Yakima River. Similar sites in Idaho and Colorado are known producers of heavy metals and acid mine drainage. I determined the effects of nine AMLs on water quality in four tributaries to the Yakima River. Archival work was conducted to determine sites that were mined and contained a mill. Each site was characterized by physical features. Water and sediment samples were collected above, at, and below each AML. Samples were analyzed for pH and heavy metal content, and evaluated to determine if the AMLs …