Geochemistry Commons^™

Application Of Uranium And Strontium Isotopes As Salinity And Paleo-Environmental Conditions Tracers:Insight From The Rio Grande River And Pedogenic Carbonates In Drylands Soils Of Southwest, Usa., Syprose Nyachoti

Open Access Theses & Dissertations

South New Mexico and west Texas regions of the northern Chihuahua Desert are characteristic of low annual rainfall and high potential evapotranspiration rates. Soils in these arid and semi-arid regions are abundant of pedogenic carbonates of various stages of development. Both surface and ground water resource in the area have high salt content; the Rio Grande river, which flows through the region is known for its high salinity downstream. Due to increasing population in cities of the region thus high food demand, irrigation activities along the river valley have enhanced crop productivity. High evapotranspiration rates and intense saline flood irrigation …

Geology, Geochemistry, And 3d Geological Modelling Of The Independencia - Los Bancos Ag-Au Epithermal Vein Systems In The Palmarejo District, Chihuahua, Mexico, Arturo Ramirez

Open Access Theses & Dissertations

The Sierra Madre Occidental (SMO) is a Cretaceous-Tertiary silicic ignimbrite province in northwestern Mexico. It is the result of tectonic and magmatic events produced by the subduction of the Farallon plate under North America (80-40 Ma) and the opening of the Gulf of California (14-12 Ma), thus forming the SMO metallogenic provinces. The Late Eocene to Oligocene was a major period of metallic mineralization hosting various deposit types, principally Ag-Au (±Pb-Zn-Cu) epithermal veins, which have been economically significant.

The study area lies in the Palmarejo district, operated by Coeur Mining Inc., which was the worldâ??s fifth largest silver producer in …

Lithostratigraphic And Geochemical Characterization Of The Upper Pennsylvanian ‘Wolfcamp D’ Shale, Midland Basin (Usa): Implications For Paleoenvironments And Unconventional Petroleum Reserviors, Patrick W. Baldwin

Theses and Dissertations--Earth and Environmental Sciences

An integrated stratigraphic analysis of a ~350 ft drill core from Upton County (Texas) has revealed pervasive variability of several key siliciclastic and carbonate lithofacies in vertical section, where organic-rich siliceous mudrock beds alternate with aluminum-rich mudrocks and calcareous gravity flow deposits. Sediment chemistry, especially major and trace elements derived from x-ray fluorescence, captures this variability with high sensitivity. The high frequency chemostratigraphic variability appears to be cyclic, and it is interpreted to represent the first example of deep-water Late Pennsylvanian cyclothems for the Midland Basin. Positive trace metal (Mo, Cr) correlations to total organic carbon and gamma ray response …

Spring Responses To Storms And Seasonal Variations In Recharge In The Middle Atlas Region Of Morocco, Brett Andrew Howell

Theses and Dissertations--Earth and Environmental Sciences

Springs in the Middle Atlas Mountains of Morocco are significant sources for public water supply. From March 2014 to May 2015, water temperatures were measured hourly at three springs (Ribaa, Sidi Rached, and Zerouka); water levels were measured hourly at Sidi Rached and Zerouka; and daily turbidity data were obtained from Ribaa. From March 2014 to March 2015, daily water samples were taken at Zerouka for analyses of the stable isotopes deuterium and oxygen-18. Hourly weather data (precipitation and air temperature) were available from March 2014 to May 2015 from Ifrane, near Zerouka. Temperature responses varied between the springs, showing …

Field, Geochronologic, And Geochemical Constraints On Late Precambrian To Early Paleozoic Terrane Accretion In The Southern Appalachian Blue Ridge Province, Emma A. Larkin

Theses and Dissertations--Earth and Environmental Sciences

Xenolith-bearing orthogneiss of Amazonian affinity discovered in the Dellwood quadrangle in the Blue Ridge basement complex represents the oldest crustal component of the southern Appalachians (1.33 – 1.37 Ga: Quinn, 2012). New U-Pb zircon ages for migmatitic paragneiss of the Cartoogechaye terrane exposed in the Dellwood quadrangle reveal two unique detrital zircon age signatures that indicate either a local eastern Laurentian margin source or an exotic source. Detailed mapping, whole rock geochemistry, and U-Pb zircon geochronology were conducted to determine whether this exotic crustal component extends farther south into the Hazelwood 7.5” quadrangle. Lithological similarities exist between paragneisses in the …

Geochemical Processes And Controls Affecting Water Quality Of The Karst Area Of Big Creek Near Mt. Judea, Arkansas, V. Brahana, J. Nix, C. Kuyper, T. Turk, F. Usrey, S. Hodges, C. Bitting, K. Ficco, E. Pollock, R. Quick, B. Thompson, J. Murdoch

Journal of the Arkansas Academy of Science

Karst regions typically are considered to be vulnerable with respect to various land-use activities, owing to the intimate association of surface and groundwater and lack of contaminant attenuation provided by most karst aquifers. Inasmuch as the soluble rocks of the karst landscape can be dissolved to create large, rapid-flow zones that compete successfully with surface streams, groundwater and subsurface flow represent a much larger component of the hydrologic budget in karst regions than in areas where non-soluble rocks predominate. Karst areas typically are distinguished by being unique, but some general approaches can be applied to characterize the hydrology of the …

Avon Alkaline Igneous Province, Missouri: Characterization Of Subcontinental Mantle Source And Evolution Via Chemical Analysis Of Olivine, Zachary William Freeman

Masters Theses

"This article presents the crystallization age of, and composition of olivine phenocrysts within an alnoite of, the Avon Alkaline Igneous Province (AAIP) of Ste. Genevieve County, Missouri. The AAIP is an ultramafic igneous province consisting of approx. 80 known intrusives of diverse lithology and texture. ⁴⁰Ar/³⁹ Ar geochronology indicates an emplacement age of 386 +/- 1 Ma, which establishes the AAIP as the only known Devonian-age ultramafic igneous body in the Midwestern U.S. Study of the AAIP provides a unique opportunity to characterize the Devonian-age subcontinental mantle and the processes that generated the suite of ultramafic rocks present …

Geochemical Signatures As A Chemostratigraphic Tool To Correlate Stacked Carbonates Of The Glorieta, Victorio Peak, Cutoff, And Upper San Andres Formations West Dog Canyon, Guadalupe Mountains, New Mexico, Eric Bergersen

Open Access Theses & Dissertations

For oil exploration, stratigraphic correlation of formations over distance and across structural complications is essential. I tested if an established method – carbon and oxygen isotope composition of carbonates (δ 18Ocarbonate, δ13Ccarbonate) and a new chemostratigraphic tool – sulfur isotope composition of Carbonate Associated Sulfate (δ34SCAS) can aid in the correlation of rock packages belonging to multiple stacked carbonate horizons from a carbonate platform.

In my study area, located in the Brokeoff Mountains, north of the Guadalupe Mountains National Park, the δ18Ocarbonate, δ 13Ccarbonate and δ34SCAS scatter strongly within single beds of the Leonardian-aged Victorio Peak Formation. In stratigraphic order, …

Uranium-Series And Strontium Isotope Ratios In Soils From Basse-Terre Island, French Guadeloupe: Insights For Rapid Soil Formation And Impact Of Dust In A Tropical Volcanic Setting, Yvette Pereyra

Open Access Theses & Dissertations

Chemical weathering of silicate rocks generates soils that contain mineral nutrients, sustain ecosystems, modify water chemistry in the hydrosphere, and regulate the global carbon cycle. Understanding the timescales of soil formation and sources of soil mineral nutrients has great implications for securing the future of agriculture and food production. However, few tools are currently available to directly quantify the rates of chemical weathering and timescales of soil formation. Uranium-series isotopes fractionate during chemical weathering and the activity ratios of (234U/238U), (230Th/238U), (238U/232Th) and (230Th/232Th) have great potential to constrain the rates and timescales of chemical weathering and soil formation in …

National Evaluation For Development And Exploration Potential Of Mineral Commodities In Produced Waters, Stephanie Ray

Open Access Theses & Dissertations

The U.S. Geological Survey recently updated a geochemical database consisting of data for approximately 160,000 produced waters samples, primarily from petroleum and geothermal reservoirs. Using major and trace elements from conventional and unconventional well types from the database, this Thesis provides a comprehensive, national evaluation for mineral commodity potential in produced waters. Produced waters contain virtually every naturally occurring element and can range in salinity to several times that of seawater. Despite the typical outlook to view produced waters as a waste, they have potential for natural resource development.

This Thesis provides, for each mineral commodity found in the produced …

Regional Geochemical Mapping Of The Superior Upland Province; Ichnology Of The Cretaceous Mesilla Valley Formation, Cerro De Cristo Rey; A New Ichnospecies Of Cardioichnus From The Cretaceous (Albian) Of New Mexico; A Pedagogy For The Cerro De Cristo Rey Tracksite; Walking In The Footprints Of Dino, Eric J. Kappus

Open Access Theses & Dissertations

This is a multi-disciplinary study that covers a variety of geoscience topics on both international borders of the continental United States. This Dissertation is the product of several separate investigations. First is a report on the landscape geochemistry of the Superior Upland Province of Minnesota, Wisconsin, and Michigan, with regional maps of 37 chemical elements interpreted in terms of bedrock, glacial reworking, and anthropogenic influence. The next 2 sections are reports on the invertebrate ichnology of the Cretaceous Mesilla Valley Formation at Cerro de Cristo Rey, including the proposal of a new ichnospecies of echinoid resting trace, Cardioichnus biloba nov. …

Rhyolite And Trachyte Formation At Lake City Caldera: Insight From Quantitative Textural And Geochemical Analyses, Jordan Lubbers

Dissertations, Master's Theses and Master's Reports

Lake City Caldera (22.93 ± 0.02 Ma) is the youngest of 15 Tertiary calderas found within the Southern Rocky Mountain Volcanic Field (SRMVF). Extreme topographical relief of the area reveals the three dimensional exposure of a complex, high-k calc-alkaline, magmatic system, which provides us with the opportunity to study, in detail, how large silicic magmas evolve in the subsurface. The Lake City igneous system is comprised of two major units: a resurgent syenite intrusion and the Sunshine Peak Tuff (Lower, Middle, and Upper). Bulk-rock analyses indicate that the Lower and Middle Sunshine Peak tuff are crystal poor and rhyolitic in …

Spatiotemporal Slip Rate Variations Along Surprise Valley Fault In Relation To Pleistocene Pluvial Lakes, Brian N. Marion

All Master's Theses

Using mapped paleoshoreline features with high-resolution topographic data and obtained radiocarbon dates on paleoshoreline tufas, I documented precise fault offsets of dated features over the last 25 ka along the Surprise Valley Fault (SVF). Fault offset measured in three lake sections within Surprise Valley ranged from 3.6 m in the southern section to 14.4 m in the central section. The offset paleoshorelines are dated to the late Pleistocene (<22 >ka) and were formed during the latest impoundment of pluvial Lake Surprise since the last glacial maximum. Slip rates vary along strike, assuming a fault dip of 68° with 0.25 ± …

Fluid Release During Eclogite Formation, North Qaidam Terrane, Western China, Jake M. Meyer

All Master's Theses

Ultrahigh-pressure (UHP, depths ≳100 km) eclogite samples from the Dulan area of the North Qaidam Terrane, western China, preserve evidence of fluid release along a prograde pressure-temperature (P-T) path. Eclogite sample D126A, Grt + Omp + Qtz + Zo + Amp + Phe + minor Rt + Hem, contains garnet porphyroblasts that preserve strong Ca zoning, recording higher core values (Grs₃₄), lower inner mantle values (Grs₂₅), increasing outer mantle values (Grs₂₈), and lower rim values (Grs₂₆). Isochemical phase diagrams (pseudosections), assuming H₂O saturation, produce a P-T path constrained by multiple …

Evolution Of A Flood Basalt Crustal Magmatic System: In Situ Mineral Data And Computational Modeling Of The Steens Basalt, Megan Graubard

All Master's Theses

Flood basalts are gigantic basaltic eruptions that modify the mass of the crust via intrusion of mantle-derived magma, and change its composition through interaction between magma and crust. The Steens Basalt, located in southeast Oregon, erupted approximately 16.8 million years ago, and is the oldest member of the Columbia River Basalt Group, the youngest and best-exposed flood basalt province on Earth. The Steens Basalt has an eruption volume of approximately 31,800 km³ and the duration of eruption is estimated to be between ~50,000 and 300,000 years. Major- and trace element whole rock data from 111 stratigraphically controlled samples from …

The Martian Surface Radiation Environment- A Comparison Of Models And Msl/Rad Measurements, Daniel Matthiä, Bent Ehresmann, Henning Lohf, Jan Köhler, Cary Zeitlin, Jan Appel, John W. Wilson

Mathematics & Statistics Faculty Publications

Context: The Radiation Assessment Detector (RAD) on the Mars Science Laboratory (MSL) has been measuring the radiation environment on the surface of Mars since August 6th 2012. MSL-RAD is the first instrument to provide detailed information about charged and neutral particle spectra and dose rates on the Martian surface, and one of the primary objectives of the RAD investigation is to help improve and validate current radiation transport models.

Aims: Applying different numerical transport models with boundary conditions derived from the MSL-RAD environment the goal of this work was to both provide predictions for the particle spectra and the radiation …

A Trace Metal Content Database Of Cave Sediments Of Midcontinent U.S.A., Matthew Dale Smith

Graduate Theses/Dissertations

The midcontinent of the United States has thousands of documented caves. These caves contain cave sediments, which are the accumulation of biological, geological, and anthropological debris. At this time there is no known database for trace metals of cave sediments of the midcontinent United States. Considering that caves host a wide variety of life, it is important to create a database to examine potential effects of trace metals on cave systems. In order to develop this baseline, 14 caves were sampled from across the midcontinent. Caves were selected based on geologic and hydrologic attributes. The sediments were analyzed for the …

Geochemical Investigation Of Anomalous Arsenic Enrichment In The Santiago Peak Volcanics Of Southern California, Elizabeth C. Johnston

Theses

Arsenic (As) is enriched in the Santiago Peak Volcanics (SPV) that crop out at Black Mountain Open Space Park in San Diego, CA. Thus, the Black Mountain SPV present an excellent opportunity to investigate As enrichment in ancient volcanic arc systems as a result of deep earth subduction zone processes. Through targeted field study of this unit, we aim to (1) confirm the volcanic arc provenance of rocks cropping out at Black Mountain, (2) investigate As enrichment in relation to volcanic arc processes, and (3) propose a model for As occurrence in the SPV. Our findings indicate Black Mountain SPV …

The Bou Dahar Jurassic Carbonate-Hosted Pb–Zn–Ba Deposits (Oriental High Atlas, Morocco): Fluid-Inclusion And C–O–S–Pb Isotope Studies, Larbi Rddad, Salah Bouhlel

Publications and Research

The Bou Dahar Pb–Zn–Ba (±Sr) is hosted in the Lower and Middle Liassic carbonate platform in the oriental High Atlas of Morocco. The paragenetic sequence includes quartz–pyrite–melnicovite–sphalerite–galena– calcite–barite ± fluorite– ± celestite. Fluid-inclusion studies were conducted on sphalerite (early mineralizing stage) and barite, and celestite (late mineralizing stage). These studies reveal two end-member fluids, a hot (~143 °C) and saline fluid (~23 wt.% NaCl eq.) and a cooler (b50 °C) and diluted fluid (~5 wt.% NaCl eq.). Based on fluid-inclusion and C–O–S isotope studies, a conclusion is reached that the Bou Dahar ore deposits were formed by the mixing of …

Geochemistry Of Upper Cretaceous Sediments Of Bozeş Formation (Apuseni Mts., Romania) – Provenance Implications, Luminiţa Zaharia, Romona Bălc, Cosmin C. Stremţan, Adriana Socaciu

School of Geosciences Faculty and Staff Publications

A whole-rock geochemical study was carried out on sandstones from the Upper Cretaceous Bozeş Formation in the southeastern part of the Apuseni Mountains (Romania) in order to constrain their provenance and depositional setting. The geochemical results were compared and integrated with previously reported provenance indicators, such as framework composition and heavy mineral assemblages. The chemical composition is similar for all samples investigated, with limited ranges for both major oxides and trace elements. The sandstones are potassic (Na₂O/K₂O < 1) and can be classified mainly as arenites with a few greywackes. Their immature to relatively mature character is revealed by the SiO₂/Al₂O₃ ratios, ranging between 3.90 and 11.25, as well as their high Sr/Rb ratios. The …

The Role Of Organic Matter In The Surface Chemistry Of Arsenic Compounds On Iron−(Oxyhydr)Oxides Studied By Atr-Ftir, Arthur Situm

Theses and Dissertations (Comprehensive)

The interaction of organic matter with the interfaces of active soil components such as iron oxides is ubiquitous within soil environments. The presence of organics at these interfaces may have implications for other soil constituents whose mobility is controlled by their ability to bind to active soil components. Most of the studies performed to date which look at these interactions are bulk/batch studies performed ex-situ. Attenuated total internal reflectance Fourier transform infrared spectroscopy (ATR-FTIR) was utilized within this work to study interactions between select model organics (citrate, oxalate and pyrocatechol) and iron−(oxyhydr)oxides, as well as their effect on the surface …

Seasonal Evolution Of Active Layer Formation In Subarctic Peat Plateaux And Implications For Dissolved Organic Matter Composition And Transfer, Jennifer L. Hickman

Theses and Dissertations (Comprehensive)

Peat-accumulating wetlands are ecosystems whose rate of photosynthetic production of organic matter is greater than that of its decomposition, resulting in a build up of soil organic matter that may take centuries to fully decompose. Carbon (C) stocks within these ecosystems are a function of inputs from photosynthesis, and losses from heterotrophic decomposition. Due to the short growing season and overall cold climate of boreal and tundra regions, C has been accumulating within these landscapes, mostly in soil organic matter, since the last glaciation. Climate change, predicted to result in rising temperatures and increased precipitation, has begun to degrade the …