Geochemistry Commons^™

Using Bromide Tracer To Measure Uranium Diffusivity In Ground Water Sediments, Francis Michael Tee, Morris E. Jones, Megan K. Dustin, Sharon Bone, John Bargar

STAR Program Research Presentations

More than 129 million liters of groundwater are contaminated with uranium at Old Rifle, Colorado – a former uranium-processing site that operated until 1958. The original Department of Energy (DOE) strategy for remediation, involving natural flushing of U from the groundwater through mixing with surface water, has not proven successful. Thin pockets of silt-, clay-, and organic-rich sediments referred to as naturally reduced zones (NRZs) act both as sinks and sources of U to the aquifer, contribute to plume persistence, and appear to be diffusion limited controlled.

To better understand how the NRZs are diffusion limited controlled, a bromide tracer …

Biogeochemical Alteration Of Particulate Pyrogenic Organic Carbon (Pyc), Jason Matthew Stuart

Master's Theses

The resistance of plant derived pyrogenic organic carbon (pyC) to abiotic and biotic means of degradation has led to increased interest in the role of pyC as a potential carbon sink, as well as a strategy for sequestering atmospheric CO2 to mitigate excess carbon emissions. Though much research pertaining to the fundamental properties of pyC degradation have been performed in a controlled lab setting, there has been very little work regarding pyC degradation in a field setting where factors such as precipitation and temperature fluctuate seasonally. This work focuses on various degradation characteristics of two …

The Role Of Blowing Snow In The Activation Of Bromine Over First-Year Antarctic Sea Ice, R. M. Lieb-Lappen, R. W. Obbard

Dartmouth Scholarship

It is well known that during polar springtime halide sea salt ions, in particular Br^-, are photochemically activated into reactive halogen species (e.g., Br and BrO), where they break down tropospheric ozone. This research investigated the role of blowing snow in transporting salts from the sea ice/snow surface into reactive bromine species in the air. At two different locations over first-year ice in the Ross Sea, Antarctica, collection baskets captured blowing snow at different heights. In addition, sea ice cores and surface snow samples were collected throughout the month-long campaign. Over this time, sea ice and surface snow …

Preliminary Isotope Assessment, La Grange Groundwater Area, Glenn A. Harrington

Natural resources commissioned reports

The Department of Agriculture and Food, Western Australia (DAFWA) is currently undertaking a Royalties for Regions funded project in the La Grange Groundwater Area south of Broome. The focus is on providing improved confidence about soil suitability and water availability for potential expansion of irrigated agriculture in the region. Groundwater in the Broome Sandstone Aquifer (BSA) is the target water resource, however before the La Grange project commenced little was known about the physical and chemical attributes of the aquifer. This report provides the results of estimated groundwater recharge and residence times using environmental tracer techniques.

Sampling of 12 existing …

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 …

Solubility And Detectability Of Hydrocarbons On The Surface Of Titan, Sandeep Singh

Graduate Theses and Dissertations

Titan’s thick atmosphere is enriched with organic compounds and its surface holds reservoirs of hydrocarbons. This makes Titan the only other candidate in our solar system (apart from Earth) to have stable liquid at the surface. The stability and characteristics of liquid and ices on the surface of Titan are of high importance in understanding its surface-atmosphere interactions. Titan’s hydrological cycle is similar to what we see on Earth, with the exception of methane (CH4) and ethane (C2H6) taking the place of water. The smoggy atmosphere veils the surface of Titan from the view of Cassini spacecraft, except at seven …

Quantitative Hermeneutics: Counting Forestructures On A Path From W.M. Davis To The Concept Of Multiple-Permeability Karst Aquifers, H. L. Vacher, Lee J. Florea

International Journal of Speleology

Hermeneutics is the theory of interpretation. One of its major components is recognizing prejudgments, or forestructures, that we bring to our objects of study. In this paper, we construct a historical narrative of the evolution of thinking about the role of caves in relation to groundwater flow in limestone, and we tabulate forestructures as they appear in the story. This account consists of three overlapping time periods: the before and after of an incident that repelled hydrogeologists and students of karst from each other in the middle of the 20^th century; a period, up to around the turn of …

Search For Life, John W. Delano Phd

Atmospheric and Environmental Science Faculty Scholarship

NASA's Astrobiology program seeks to determine the origin and distribution of life in the Milky Way galaxy using scientific expertise from many disciplines (e.g., astronomy, biochemistry, geochemistry). This presentation, which provides an overview of the progress that has been made in this effort, was delivered on 23 June 2015 at the Green Mountain Academy for Lifelong Learning in Manchester, VT. With NASA's development of the Space Launch System (SLS), vigorous multi-disciplinary scientific research, and additional spacecraft (e.g., TESS) for finding and analyzing planets orbiting other stars, exciting discoveries will continue.

Growth In Stratospheric Chlorine From Short-Lived Chemicals Not Controlled By The Montreal Protocol, R. Hossaoni, M. P. Chipperfield, A. Saiz-Lopez, J. J. Harrison, R. Von Glasow, R. Sommariva, E. Atlas, M. Navarro, S. A. Montzka, W. Feng, P. F. Bernath

Chemistry & Biochemistry Faculty Publications

We have developed a chemical mechanism describing the tropospheric degradation of chlorine containing very short-lived substances (VSLS). The scheme was included in a global atmospheric model and used to quantify the stratospheric injection of chlorine from anthropogenic VSLS (Cl_y^VSLS) between 2005 and 2013. By constraining the model with surface measurements of chloroform (CHCl₃), dichloromethane (CH₂Cl₂), tetrachloroethene (C₂Cl₄), trichloroethene (C₂HCl₃), and 1,2-dichloroethane (CH₂ClCH₂Cl), we infer a 2013 Cl_y^VSLS mixing ratio of 123 parts per trillion (ppt). Stratospheric injection …

Fluxes Of Dissolved Organic Carbon During Storm Events In The Neponset River Watershed, Keith Thomas Cialino

Graduate Doctoral Dissertations

The transport of dissolved organic carbon (DOC) and chromophoric dissolved organic matter (CDOM) from land to coastal environments strongly influences coastal ecosystems. The presence of first flush phenomena due to rainwater runoff traveling from land into waterways can greatly affect carbon fluxes to coastal areas. This research utilizes sensors, autosamplers, and standard watershed sampling in order to assess for the presence of first flush and its significance. A rainfall simulator was built in order to collect runoff on two land use types. Time series data suggest that first flush of dissolved organic carbon was present for all rainfall intensities simulated …

Nanodiamond Extraction At A Potential Impact Location, Joel Kathan

DePaul Discoveries

Meteoritic or cometary impacts create the temperature and pressure conditions necessary to form nanodiamonds (NDs). The presence of extracted NDs from rocks of the time and locations of extinctions, fires, or known environmental changes are commonly used to confirm that a theorized cosmic impact occurred to trigger those events. Samples were obtained from an archeological site described in the Old Testament of the Bible as having been destroyed by the God of the Old Testament.† To see if the historical description of Biblical events might have been triggered by a cometary impact or explosion, an attempt was made to …

The State Of The Oligocene Icehouse World: Sedimentology, Provenance, And Stable Isotopes Of Marine Sediments From The Antarctic Continental Margin, Daniel William Hauptvogel

Dissertations, Theses, and Capstone Projects

The Oligocene Epoch (34-23 Ma) was a dynamic time in Antarctica, with previous ice volume estimates suggesting fluctuations from below 50 % up to 140 % of modern all while atmospheric CO₂ decreased from above 1,000 ppm in the Early Oligocene to near modern levels by the Late Oligocene. Most of what is known about the Oligocene Antarctic cryosphere however, is derived from distal sedimentary records that can only provide a generalized view of the cryospheric dynamics in Antarctica. To better understand regional differences in Antarctic glacial dynamics, proximal records are needed. This dissertation advances our understanding of these …

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 …

Stable Isotopes As A Tool To Characterize Carbon Cycling And Develop Hydrologic Budgets In Mantled Karst Settings, Katherine Knierim

Graduate Theses and Dissertations

Isotopes of water (δ2H/δ18O), carbon dioxide (δ13C-CO2), and dissolved inorganic carbon (δ13C-DIC) were used to explore water quality, trace carbon cycling, and quantify recharge sources through mantled karst and into Blowing Spring Cave (BSC). Of the possible sources of contamination in the BSC recharge area, septic-tank effluent was hypothesized to degrade water quality at the spring outlet of BSC because of the dominance of septic tanks for waste treatment, unsuitable topography and soil for septic-tank absorption fields, increased nitrate and chloride concentrations concomitant with increased urbanization, and increased Escherichia coli with discharge. Carbon cycling between the soil and BSC was …

Source Constraints Of Ore Metals In Mississippi Valley-Type Deposits In Central And Eastern Tennessee Using Pb Isotopes, Austin Moyers

Graduate Theses and Dissertations

The Mississippi Valley-Type (MVT) Central and East Tennessee (TN) Districts contain economically significant lead-zinc deposits that occur in the Early Ordovician carbonates of the Knox Group. Although both districts share similar host rock, have similar temperatures of formation, and typically fill open spaces of collapse breccias or replace their host carbonates, previous studies may suggest that these ores did not form from the same mineralizing fluids and may have different Pb sources. Nu Plasma MC-ICP-MS Pb isotopic analyses on sulfides from Central and East TN were conducted and the metal sources evaluated. Results were plotted on covariation diagrams with respect …

Using Kriging, Cokriging, And Gis To Visualize Fe And Mn In Groundwater, Crystal Johnson

Electronic Theses and Dissertations

For aesthetic, economic, and health-related reasons, allowable concentrations of iron (Fe) and manganese (Mn) found present in drinking water are 0.3 mg/L and 0.05 mg/L, respectively. Water samples taken from private drinking wells in the rural communities within Buncombe County, North Carolina contain amounts of these metals in concentrations higher than the suggested limits. This study focused on bedrock geology, elevation, saprolite thickness, and well depth to determine factors affecting Fe and Mn. Using ArcGIS 10.2, spatial trends in Fe and Mn concentrations ranges were visualized, and estimates of the metal concentrations were interpolated to unmonitored areas. Results from this …

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 …

Carbon Isotope Variations Associated With A Middle Ordovician Karstic Unconformity, Patricia Suzanne Williams

UNLV Theses, Dissertations, Professional Papers, and Capstones

Large negative carbon isotope (δ¹³C) excursions have been documented from late Neoproterozoic-Paleozoic successions. These δ¹³C excursions have been widely used for regional and global stratigraphic correlation, particularly in strata with limited paleontological and radiometric age controls. Recent studies, however, argued that some negative δ¹³C excursions from stratigraphic record may have been resulted from meteoric/burial diagenesis, which commonly shifts both carbon and oxygen isotopes toward lower values. Testing the diagenetic origin of δ¹³C excursions in stratigraphic successions without independent stratigraphic framework has been difficult because it evolves into circular arguments about stratigraphic completeness …

Terrestrial Impacts Of The Central Atlantic Magmatic Province On Western Pangea, Todd Kenneth Knobbe

Graduate Theses and Dissertations

Earth's climate is predominantly controlled by the fluctuation of greenhouse gases, specifically CO2 and CH4, over geologic time. The late Triassic is a period of abrupt climate change that has been associated with a disruption to the global carbon cycle due the emplacement of the Central Atlantic Magmatic Province (CAMP). Evidence has shown that this global carbon cycle perturbation may be the culprit for the end-Triassic extinction. The Whitmore Point Member of the Moenave Formation is a lacustrine deposit with a disputed age of either late Triassic or early Jurassic and currently no absolute dating techniques can be applied to …

Influence Of Road Salt Deicers On Anaerobic Respiration And Metal Speciation In Soils, Danielle Dupuis

Honors Theses

Road salt deicers, especially NaCl and CaCl₂, are used throughout the world on paved areas during the winter. Previous studies suggest that road salt deicers can alter the biogeochemistry of sediment located near roadways and influence the mobility of heavy metals. The goal of this study is to investigate the influence of CaCl₂ on wetland soil biogeochemistry, especially trace metal speciation. Sediment cores were collected in the fall from a freshwater wetland near an urban kettle lake (Asylum Lake, Kalamazoo, MI) and incubated for 100 days in deionized water (control), 5 g/L of CaCl₂, or …

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, …

On The Influence Of Ionic Strength On Radium And Strontium Sorption To Sandy Loam Soils, Brian A. Powell, Todd Miller, Daniel I. Kaplan

Journal of the South Carolina Academy of Science

Models which can estimate environmental transport of radioactive contaminants in natural and engineered systems are required to 1) deploy effective remediation strategies for contaminated sites, 2) design waste repositories for future waste streams, and 3) ensure protection of human and environmental health in all cases. These models require accurate transport parameters in order to correctly predict how these contaminants will move in the subsurface. This work aimed to determine more accurately the distribution coefficients for radium and strontium sorption to Savannah River Site (SRS) soils. Radium and strontium sorption to the soils was found to be highly dependent upon ionic …

Biogeochemical Cycling In A Headwater Stream And Riparian Zone, A. Capri Gillam

Graduate Theses & Non-Theses

Several teams of researchers at multiple universities are currently measuring annual and seasonal fluxes of carbon dioxide and other greenhouses gases (nitrous oxide and methane) in riparian wetlands and upland forests in the Tenderfoot Creek Experimental Forest (TCEF), a subalpine watershed in the Little Belt Mountains, Montana. In the current thesis, the author characterized the geochemistry and stable carbon isotope composition of shallow groundwater, soil water, and stream water in upper Stringer Creek, near sites that are being investigated for gas chemistry and microbial studies. It was hypothesized that if methanogenesis were a dominant process in the riparian wetlands of …

Geochemical Assessment And Separation Of Source Waters In The Upper Boulder River Watershed Near Boulder, Mt, John Anderson

Graduate Theses & Non-Theses

Environmental samples were collected at three surface water sites between 5/21/2011 and 11/21/2014 along the Upper Boulder River near Boulder Montana. The sites were located at Bernice (within the mountain block), near the High Ore drainage (near the mountain block/basin transition), and at the USGS Gauging Station near Boulder, Montana (within the basin). The parameters measured in the field were SC, temperature, and alkalinity with occasional pH measurements. We collected samples for anions, cations, and stable isotopes in the catchment. We identified endmembers by sampling snow and groundwater and determined from available data an approximate endmember for rain, snow, and …

Investigation Of The Potential For Algaenan To Produce Hydrocarbon Based Fuels From Algae By Hydrous Pyrolysis, Wassim Adel Obeid

Chemistry & Biochemistry Theses & Dissertations

The use of algae as a feedstock for hydrous pyrolysis has a high potential for producing biofuels. The non-food nature of algae in addition to the various advantages associated with the hydrous pyrolysis process makes this combination for the production of biofuels of high interest. However, current results from algae processing have alluded to some challenges: byproducts arising from the thermal transformation of carbohydrates and proteins, which become incorporated in the oil fraction, result in high oxygen and nitrogen contents of the oil. Accordingly, this produces an oil of low quality for refineries. This dissertation investigates use of a pretreatment …

The Relationship Between Carbon Dioxide Concentration And Visitor Numbers In The Homothermic Zone Of The Balcarka Cave (Moravian Karst) During A Period Of Limited Ventilation, Marek Lang, Jiří Faimon, Camille Ek

International Journal of Speleology

The evolution of CO₂ levels with and without human presence was studied in a selected site (Gallery Chamber) of the homothermic zone of the Balcarka Cave (Moravian Karst, Czech Republic) during the fall, a period of limited ventilation. There were recognized various factors controlling the cave CO₂ levels under different conditions in the exterior and interior. When visitors were absent, CO₂ levels were controlled by the advective CO₂ fluxes linked to cave airflows and reaching up to ~1.5x10^-3 mol s^-1. These fluxes exceed by orders of magnitude the exchanged diffusive fluxes (up to …

Split-Beam Echosounder Observations Of Natural Methane Seep Variability In The Northern Gulf Of Mexico, Kevin W. Jerram, Thomas C. Weber, Jonathan Beaudoin

Center for Coastal and Ocean Mapping

A method for positioning and characterizing plumes of bubbles from marine gas seeps using an 18 kHz scientific split-beam echo sounder (SBES) was developed and applied to acoustic observations of plumes of presumed methane gas bubbles originating at approximately 1400 m depth in the northern Gulf of Mexico. A total of 161 plume observations from 27 repeat surveys were grouped by proximity into 35 clusters of gas vent positions on the seafloor. Profiles of acoustic target strength per vertical meter of plume height were calculated with compensation for both the SBES beam pattern and the geometry of plume ensonification. These …

Characterization Of The Major Ions Of Coal Creek Near Cedar City, Utah, Jared Bryce Weaver, Christopher Lamb, Kim Weaver, Jason Kaiser, J. Ty Redd

The Compass: Earth Science Journal of Sigma Gamma Epsilon

The major ions of Coal Creek near Cedar City, in southwest Utah, were measured to determine if there were any differences in ion concentrations in July of 2014 as compared with spring measurements of 2012 and 2013. Past analyses have shown higher ion concentrations in lower regions of Coal Creek despite the apparent lack of water input. This research is aimed to better characterize these abrupt increases in concentration and determine if these trends varied when samples were acquired in the summer vs. in the spring when sample acquisition has occurred in the past. Environmental water samples were collected at …

Origin And Quantification Of Diffuse Co2 And H2s Emission At Crater Hills, Yellowstone National Park, Peipei Lin

Dissertations, Master's Theses and Master's Reports - Open

At Crater Hills, a thermally-altered area adjoining the Sour Creek resurgent dome that is located within the Yellowstone Caldera, we characterized volatile emissions based upon our soil degassing measurements and soil gas chemistry in 2014 and fumarole gas chemistry in 2007 (Bergfeld et al., 2011). The investigation at Crater Hills on its diffuse gases isotopes and CO2, H2S emission improve our understanding on its gas emission mode – including total emission and spatial distribution, and contribute to a more accurate estimation of total CO2 emission at Yellowstone volcanic system. The total emission of CO2 interpolated by sequential Gaussian simulation method …

Morphological, Structural, And Spectral Characteristics Of Amorphous Iron Sulfates, Elizabeth Sklute, Heidi Jensen, Deanne Rogers, Richard Reeder

Department of Geosciences Faculty Publications

Current or past brine hydrologic activity on Mars may provide suitable conditions for the formation of amorphous ferric sulfates. Once formed, these phases would likely be stable under current Martian conditions, particularly at low- to mid-latitudes. Therefore, we consider amorphous iron sulfates (AIS) as possible components of Martian surface materials. Laboratory AIS were created through multiple synthesis routes and characterized with total X-ray scattering, thermogravimetric analysis, scanning electron microscopy, visible/near-infrared (VNIR), thermal infrared (TIR), and Mössbauer techniques. We synthesized amorphous ferric sulfates (Fe(III)2(SO4)3 · ~ 6–8H2O) from sulfate-saturated fluids via vacuum dehydration or exposure to low relative humidity (