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Geochemistry

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Articles 91 - 120 of 185

Full-Text Articles in Geochemistry

Carbon Flux And Weathering Processes In Icelandic Glacial-Fed Rivers, Allison Quiroga Apr 2018

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 …


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 Mar 2018

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 …


Abandoned Mine Land Impacts On Tributaries In The Upper Yakima River Watershed, Eastern Cascades, Washington, Scott Kugel Jan 2018

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 …


Environmental Monitoring And Peat Assessment Using Multivariate Analysis Of Regional-Scale Geochemical Data, Jennifer M. Mckinley, Eric Grunsky, Ute Mueller Jan 2018

Environmental Monitoring And Peat Assessment Using Multivariate Analysis Of Regional-Scale Geochemical Data, Jennifer M. Mckinley, Eric Grunsky, Ute Mueller

Research outputs 2014 to 2021

A compositional multivariate approach was used to analyse regional-scale soil geochemical data obtained as part of the Tellus Project generated by the Geological Survey of Northern Ireland. The multi-element total concentration data presented comprise X-ray fluorescence (XRF) analyses of 6862 rural soil samples collected at 20-cm depth on a non-aligned grid at one site per 2km2" role="presentation">2km2. Censored data were imputed using published detection limits. Each soil sample site was assigned to the regional geology map, resulting in spatial data for one categorical variable and 35 continuous variables comprised of individual and amalgamated elements. This paper examines the extent …


Provenance Analysis Of The Grover Gravel Using Detrital Zircon Geochronology, Petrology And Heavy Mineral Analysis, Grant Spoering Dec 2017

Provenance Analysis Of The Grover Gravel Using Detrital Zircon Geochronology, Petrology And Heavy Mineral Analysis, Grant Spoering

Graduate Theses/Dissertations

The Grover Gravel in the St. Louis, Missouri area contains a mix of chert, quartzite, jasper, and ironstone in clast sizes ranging up to 60 cm. The gravel varies in thickness from a veneer to over 30 feet and rests on upland surfaces at elevations sometimes exceeding 300 feet above the floors of major valleys. A pre-Pleistocene age generally has been proposed or assumed for the gravel, which classically has been interpreted to be a meandering-stream deposit atop an extensive flat upland surface, which was subsequently eroded and dissected by rejuvenated streams. However, large quartzite boulders in the gravel also …


Geochemical Characteristics And Storm Dynamics Of Surface Waters And Groundwater At Eastern Kentucky University’S Meadowbrook Farm, Madison County, Kentucky, Reid E. Buskirk, Walter S. Borowski, Jonathan M. Malzone Nov 2017

Geochemical Characteristics And Storm Dynamics Of Surface Waters And Groundwater At Eastern Kentucky University’S 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’s Meadowbrook Farm raises crops and livestock, contributing dissolved nutrients to the neighboring Muddy Creek watershed. Consequently, the Farm is developing methods to sequester and limit nutrient contamination.

Before phosphorous sequestration methods can be tested, the geochemistry of surface water and groundwater on the Farm need to be better understood to determine hydrological pathways. We use naturally-occurring, dissolved cations as tracers to identify the contribution of different water sources and interpret storm events.

Water samples taken from springs (groundwater), surface water, and storm …


Investigating Core Shale Depositional Environments Of Late Pennsylvanian Cyclothems Utilizing Geochemical Proxies To Test The Superestuarine Model, Bryce A. Mathis Aug 2017

Investigating Core Shale Depositional Environments Of Late Pennsylvanian Cyclothems Utilizing Geochemical Proxies To Test The Superestuarine Model, Bryce A. Mathis

LSU Master's Theses

The Late Paleozoic Midcontinent Sea (LPMS) inundated vast areas of the North American interior during glacio-eustatic transgressions, depositing widespread black shales facies within the core shale intervals of major cyclothems. These black shale deposits are unique because no modern analogs can adequately explain the depositional environments and model for organic matter preservation across such vast ancient epicontinental settings. One possible explanation is that a superestuarine circulation system developed across the LPMS during humid interglacial phases, which promoted strong water column stratification and benthic anoxia.

The goal of this research was to test the validity of the superestuarine estuarine model and …


Urban Detention Basin Contamination With Polycyclic Aromatic Hydrocarbons (Pahs) And Metals, Holly Marie Duff Aug 2017

Urban Detention Basin Contamination With Polycyclic Aromatic Hydrocarbons (Pahs) And Metals, Holly Marie Duff

Graduate Theses/Dissertations

Polycyclic aromatic hydrocarbons (PAHs) are organic compounds that can be toxic to wildlife and humans when released to the environment. Coal-tar sealants, which are applied to parking lots or driveways, contribute up to 1,000 times more PAHs than alternative sealants. Over time, these sealants abrade and are transported into drainage networks. Coal-tar sealants are currently used in Springfield, Missouri, however the extent of PAH contamination throughout urban drainage systems is unclear. This study focused on PAH contamination within an urban detention basin on the Missouri State University campus which receives runoff from several coal-tar sealed parking lots. Sediment samples collected …


Foundations For A Geobiochemical Characterization Of Mudpots In Yellowstone National Park, Georgia Dahlquist Jul 2017

Foundations For A Geobiochemical Characterization Of Mudpots In Yellowstone National Park, Georgia Dahlquist

Graduate Theses & Non-Theses

Mudpots are acidic, turbid thermal features formed by the argillic or sericitic alteration of rock with enough fluid to create a viscous feature. Prior to this research, the combination of interdisciplinary sampling for geochemistry, mineralogy, and microbiology of rhyolite hosted mudpots, particularly in chemically distinct subregions of an area, remained largely unavailable. This work discusses mudpots and nearby hot springs sampled in Yellowstone National Park (YNP) in July 2016 and the measured in situ pH, temperature, and conductivity values, and dissolved oxygen concentrations. Water, filtered via gravity pre-filtration and 1.2 μm and 0.8/0.2μm syringe filtration, yielded δD and δ18O values …


Magmatic Hydrothermal Alteration And Secondary Post-Shock Features In Martian Olivine-Phyric Basalt Northwest Africa 10416; Petrology And Geochemistry Of Primitive Achondrite Northwest Africa 11042, Zoltan Vaci May 2017

Magmatic Hydrothermal Alteration And Secondary Post-Shock Features In Martian Olivine-Phyric Basalt Northwest Africa 10416; Petrology And Geochemistry Of Primitive Achondrite Northwest Africa 11042, Zoltan Vaci

Earth and Planetary Sciences ETDs

The Martian olivine-phyric basalt Northwest Africa (NWA) 10416 contains large olivine xenocrysts whose cores have been stained brown by hydrothermal alteration and whose rims are composed of pristine olivine overgrowths. Microanalysis of these olivine cores reveals various degrees of amorphization, some of which have been overprinted by terrestrial weathering, evident as part of a weathering rind along the exposed surface of the meteorite. Studies of a completely unweathered terrestrial analogue basalt from southern Colorado reveal similar features and indicate that both basalts were altered in a supersolidus magma chamber setting. The alteration features in NWA 10416 thus imply the presence …


Catalyzed Synthesis Of Zinc Clays By Prebiotic Central Metabolites, Marcelo I. Guzman, Ruixin Zhou, Kaustuv Basu, Hyman Hartman, Christopher J. Matocha, S. Kelly Sears, Hajatollah Vali Apr 2017

Catalyzed Synthesis Of Zinc Clays By Prebiotic Central Metabolites, Marcelo I. Guzman, Ruixin Zhou, Kaustuv Basu, Hyman Hartman, Christopher J. Matocha, S. Kelly Sears, Hajatollah Vali

Chemistry Faculty Publications

How primordial metabolic networks such as the reverse tricarboxylic acid (rTCA) cycle and clay mineral catalysts coevolved remains a mystery in the puzzle to understand the origin of life. While prebiotic reactions from the rTCA cycle were accomplished via photochemistry on semiconductor minerals, the synthesis of clays was demonstrated at low temperature and ambient pressure catalyzed by oxalate. Herein, the crystallization of clay minerals is catalyzed by succinate, an example of a photoproduced intermediate from central metabolism. The experiments connect the synthesis of sauconite, a model for clay minerals, to prebiotic photochemistry. We report the temperature, pH, and concentration dependence …


Mineralogy And Geochemistry Of The Heddleston Porphyry Cu-Mo Deposit, Montana, Ben Schubert Apr 2017

Mineralogy And Geochemistry Of The Heddleston Porphyry Cu-Mo Deposit, Montana, Ben Schubert

Graduate Theses & Non-Theses

The Heddleston porphyry Cu-Mo deposit is located in Lewis and Clark County, Montana, near the headwaters of the Blackfoot River. It is immediately west of the historic Mike Horse mine, an important producer of Pb-Zn from polymetallic veins and lodes. The Heddleston property was explored extensively by the Anaconda Company in the 1960s and 1970s, but was never mined. Specimens of polished drill core from the deposit are archived in the Anaconda Research Collection at Montana Tech campus. The purpose of this research project was to use the archived samples to examine the geochemistry and mineralogy of the Heddleston and …


Cycling Of Gypsiferous White Sands Aerosols In The Shallow Critical Zone At White Mountain, New Mexico, Patrick Richard Rea Jan 2017

Cycling Of Gypsiferous White Sands Aerosols In The Shallow Critical Zone At White Mountain, New Mexico, Patrick Richard Rea

Open Access Theses & Dissertations

Dry deposition significantly affects evolution of the critical zone by nutrient supply and contributing to soil genesis. Dust influx and cycling in soils are difficult to quantify because dust sources can be chemically similar to local soils. White Sands, New Mexico, emits gypsum dust with a unique chemical and isotopic signature, providing an opportunity to investigate dust deposition and its movement in soils. This study evaluated the mobility of White Sands dust particles in the critical zone at White Mountain, New Mexico, a highland 100 km downwind. Four soil profiles were collected over limestone, igneous, mixed limestone and dolostone, and …


Mercury Increases In Lake Tanganyika Since ~1850, Troy A. Bole Jan 2017

Mercury Increases In Lake Tanganyika Since ~1850, Troy A. Bole

Williams Honors College, Honors Research Projects

A series of three sediment cores were collected in Lake Tanganyika, Africa, and were analyzed for mercury concentrations. For all three cores, a decrease in mercury (Hg) levels was observed from the 1600’s (appx. 20 ng/g) until concentrations reached a minimum during the mid-1800’s (appx. 10 ng/g). The mid-1800’s marked a change from decreasing mercury levels to an increase over the following century. The core tops (circa 2006) have concentrations greater than 70 ng/g. The onset of the rise in mercury concentrations coincides with the beginning of the Industrial Revolution in the mid to late 18th century. Relationships between …


Using Strontium Isotopes In Conjunction With Major, And Trace Elements To Identify Water/Rock Interaction In The Upper Kittitas County, Washington, James Patterson, Carey Gazis Jan 2017

Using Strontium Isotopes In Conjunction With Major, And Trace Elements To Identify Water/Rock Interaction In The Upper Kittitas County, Washington, James Patterson, Carey Gazis

All Master's Theses

The complex bedrock lithologies in the Upper Kittitas County provide an ideal setting for developing isotopic methodology to identify groundwater sources and track flow paths through water-rock interaction. A wide range of 87Sr/86Sr (0.7040 to 0.7068) in surface waters, springs, and groundwater from wells was found, allowing for identification of the individual signatures of lithologic units. Rock leachates from different lithology were compared to water samples to determine a general 87Sr/86Sr signature of the water-rock interaction for that lithology. The signatures identified were systematically lower than their associated waters, but similar enough to identify the expected 87Sr/86Sr of water-rock interaction …


Geothermometry Of Two Cascade Geothermal Systems, Donnel Alexander Malkemus Dec 2016

Geothermometry Of Two Cascade Geothermal Systems, Donnel Alexander Malkemus

Dissertations and Theses

For this thesis I applied classical and multi-component geothermometry techniques to new water chemistry data from Breitenbush Hot Springs, Oregon and the Wind River Valley, Washington. A total of 20 well, spring, and stream samples from Breitenbush Hot Springs and 4 spring samples from the Wind River Valley were collected and analyzed for major, minor, and select trace anions and cations, as well as stable oxygen and hydrogen isotopes. I used two computer programs, GeoT and RTEst, to conduct multi-component geothermometry reservoir condition estimation on each water sample. Water chemistry data from Breitenbush Hot Springs indicates a range of thermal, …


Using Geochemistry And Strontium Isotopic Ratios (87sr/86sr) To Determining Water Mixing And Sources In The Picher Mining District, William Daniel Ketcheside Nov 2016

Using Geochemistry And Strontium Isotopic Ratios (87sr/86sr) To Determining Water Mixing And Sources In The Picher Mining District, William Daniel Ketcheside

Theses and Dissertations

The mining of lead and zinc ores in the Tri-State Mining District of Kansas, Missouri, and Oklahoma resulted in some of the most severe environmental degradation in the country. Large amounts of waste rock, known as ‘chat’, were produced during mining and left in surface piles in the surrounding area. These chat piles, located mostly near the town of Picher, Oklahoma contain potentially harmful elements that can be leached from the rock into local streams and sediment. The mines also filled with water after mining ceased and have discharged contaminated water to nearby waterways, as well as resulted in groundwater …


Record Of Massive Upwellings From The Pacific Large Low Shear Velocity Province, Pilar Madrigal, Esteban Gazel, Kennet E. Flores, Michael Bizimis, Brian Jicha Nov 2016

Record Of Massive Upwellings From The Pacific Large Low Shear Velocity Province, Pilar Madrigal, Esteban Gazel, Kennet E. Flores, Michael Bizimis, Brian Jicha

Faculty Publications

Large igneous provinces, as the surface expression of deep mantle processes, play a key role in the evolution of the planet. Here we analyse the geochemical record and timing of the Pacific Ocean Large Igneous Provinces and preserved accreted terranes to reconstruct the history of pulses of mantle plume upwellings and their relation with a deep-rooted source like the Pacific large low-shear velocity Province during the Mid-Jurassic to Upper Cretaceous. Petrological modelling and geochemical data suggest the need of interaction between these deep-rooted upwellings and mid-ocean ridges in pulses separated by ∼10–20 Ma, to generate the massive volumes of melt …


Development And Curation Of The Sample Data Library For The Astrobiogeochemistry Laboratory, Meika R. Nwaomah, Lorenia Jimenez, Michael Tuite Aug 2016

Development And Curation Of The Sample Data Library For The Astrobiogeochemistry Laboratory, Meika R. Nwaomah, Lorenia Jimenez, Michael Tuite

STAR Program Research Presentations

In 2011, the National Science Foundation (NSF) initiated EarthCube, an integrated cyber infrastructure initiative, to tackle challenges within geoscience research. EarthCube’s goal is to improve public access and collaboration within the geoscience community. During the summer of 2015, the Astrobiogeochemistry Laboratory (abcLab) joined the collective efforts of EarthCube by developing the Sample Data Library (SDL) for the Jet Propulsion Laboratory (JPL). The main focus of the SDL concentrates on effectively curating the samples collected by researchers within the Planetary Chemistry and Astrobiology section at JPL. The goal of this summer internship was to assimilate field notes, images, and from data …


An Investigation Of Hydrogeologic, Stratigraphic, And Structural Controls On Acer Grandidentatum Communities In A Karst Landscape, Owl Mountain Province, Fort Hood Military Installation, Texas, Melinda S. Faulkner May 2016

An Investigation Of Hydrogeologic, Stratigraphic, And Structural Controls On Acer Grandidentatum Communities In A Karst Landscape, Owl Mountain Province, Fort Hood Military Installation, Texas, Melinda S. Faulkner

Electronic Theses and Dissertations

The Owl Mountain Province is located within the Fort Hood Military Installation, an approximately 880 km2 installation established in the 1940s in Bell and Coryell counties, Texas, which has undergone extensive land use changes associated with military training, maintaining much of the vegetation in early succession. This study investigates thelithologic, stratigraphic, and structural controls on the hydrologic, hydrogeologic, and geomorphologic evolution of the Owl Mountain Province as expressed by mesic vegetation communities, including Pleistocene relicts Acer grandidentatum, within karst terrains. These systems exhibit complexly overprinted speleogenetic evolutions within a dynamic groundwater regime resulting from regional climate shifts throughout the …


Mineralogy And Environmental Geochemistry Of Slag In Lower Area One, Butte, Montana, Jenna Kaplan Apr 2016

Mineralogy And Environmental Geochemistry Of Slag In Lower Area One, Butte, Montana, Jenna Kaplan

Graduate Theses & Non-Theses

Butte, Montana is the host to a Cu-Mo porphyry deposit and has been a location of mining interest since 1864. Once copper ore is removed from this deposit it goes through a smelting process. Copper smelting processes consist of roasting, smelting, concentrating, and fire refining. During smelting, metals are separated from the waste, or gangue material. Slag is the waste material from these processes. Non-ferrous slag, such as a copper ore, removes iron and silica from the original ore. There is much interest in slag postproduction for there is often still a significant weight percent of metals trapped within a …


Geochemical And Petrological Studies On The Origin Of Nickel-Copper Sulfide Mineralization At The Eagle Lntrusion In Marquette County, Michigan, Benjamin Davis Hinks Apr 2016

Geochemical And Petrological Studies On The Origin Of Nickel-Copper Sulfide Mineralization At The Eagle Lntrusion In Marquette County, Michigan, Benjamin Davis Hinks

Masters Theses

The Eagle magmatic intrusion is located in the Upper Peninsula of Michigan in Marquette County. It hosts a high grade magmatic nickel-copper sulfide ore deposit. Country rocks surrounding the Eagle intrusion are metamorphosed slate and greywacke of the Proterozoic Michigamme Formation and Archean granite-gneiss. The aim of this thesis is to characterize the magmatic sulfide mineral deposit at Eagle and to establish its relationship to the surrounding host rocks of the Baraga Basin area.

The Eagle East intrusion is located 600 meters east of the Eagle intrusion. These two intrusions are similar in composition and sulfide mineralization. Sulfide textural domains …


Geochemical And Petrological Characterizations Of Peridotite And Related Rocks In Marquette County, Michigan, Andrew Lloyd Sasso Apr 2016

Geochemical And Petrological Characterizations Of Peridotite And Related Rocks In Marquette County, Michigan, Andrew Lloyd Sasso

Masters Theses

This study characterizes the following rock units in Marquette County, Michigan in terms of geochemistry and petrology: (1) Presque Isle Peridotite, (2) Deer Lake Peridotite, (3) Yellowdog Peridotite, and (4) Black Rock Point Gabbro. Analyses were conducted to determine if any petrological or geochemical relationships exist between these units, and to assess the potential of these units to host magmatic sulfide deposits.

The generated data and chosen geotectonic proxies indicate that Black Rock Point Gabbro and Deer Lake Peridotite crystallized from unrelated magmas, probably during the formation of the Great Lakes Tectonic Zone (2.7-1.85 Ga). No evidence was found which …


Natural Acid Rock Drainage And Ferricrete Deposit Chemistry Of The Judith Mountains, Montana, Sara Edinberg Apr 2016

Natural Acid Rock Drainage And Ferricrete Deposit Chemistry Of The Judith Mountains, Montana, Sara Edinberg

Graduate Theses & Non-Theses

The Judith Mountains are a low-elevation “island” mountain range in east-central Montana composed of a series of laccoliths and stocks cut by coarse-grained alkali granite and tinguaite dikes. The geology of the Judith Mountains in the vicinity of Red Mountain and Judith Peak, two of the tallest mountains in the range, is conducive to the creation of headwater streams that are naturally acidic. Extensive limonite staining on Red Mountain attests to the widespread presence of disseminated pyrite in hydrothermally altered porphyry rock. However, no major historical mining operations are known to the area. The acidic streams undergo neutralization in pH …


Avon Alkaline Igneous Province, Missouri: Characterization Of Subcontinental Mantle Source And Evolution Via Chemical Analysis Of Olivine, Zachary William Freeman Jan 2016

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 …


National Evaluation For Development And Exploration Potential Of Mineral Commodities In Produced Waters, Stephanie Ray Jan 2016

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 …


Rhyolite And Trachyte Formation At Lake City Caldera: Insight From Quantitative Textural And Geochemical Analyses, Jordan Lubbers Jan 2016

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 …


A Trace Metal Content Database Of Cave Sediments Of Midcontinent U.S.A., Matthew Dale Smith Jan 2016

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 Jan 2016

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 …


Geochemistry Of Upper Cretaceous Sediments Of Bozeş Formation (Apuseni Mts., Romania) – Provenance Implications, Luminiţa Zaharia, Romona Bălc, Cosmin C. Stremţan, Adriana Socaciu Jan 2016

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 …