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Articles 841 - 870 of 1536
Full-Text Articles in Geochemistry
Geochemical And Petrological Studies On The Origin Of Nickel-Copper Sulfide Mineralization At The Eagle Lntrusion In Marquette County, Michigan, Benjamin Davis Hinks
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
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
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 …
U-Pb Dating Of Speleogenetic Dolomite: A New Sulfuric Acid Speleogenesis Chronometer, Victor J. Polyak, Paula P. Provencio, Yemane Asmerom
U-Pb Dating Of Speleogenetic Dolomite: A New Sulfuric Acid Speleogenesis Chronometer, Victor J. Polyak, Paula P. Provencio, Yemane Asmerom
International Journal of Speleology
The 1100-meter Big Room elevation level of Carlsbad Cavern, New Mexico USA, formed 4 Ma by hypogenic sulfuric acid speleogenesis (SAS). The age of the Big Room level of 4.0 ± 0.2 Ma was previously determined by dating alunite, a byproduct of speleogenesis, using the 40Ar/39Ar method. Duplication of these results is possible by radiometric dating of other byproducts interpreted to be speleogenetic (a byproduct of speleogenesis) such as calcite and dolomite in certain settings. XRD and TEM analyses of sample 94044, a piece of crust collected within the Big Room level of SAS just below Left …
Agriculture Causes Nitrate Fertilization Of Remote Alpine Lakes, Elizabeth J. Hundey, Sam S.D. Russell, Fred Longstaffe, Katrina A. Moser
Agriculture Causes Nitrate Fertilization Of Remote Alpine Lakes, Elizabeth J. Hundey, Sam S.D. Russell, Fred Longstaffe, Katrina A. Moser
Earth Sciences Publications
Humans have altered Earth’s nitrogen cycle so dramatically that reactive nitrogen (Nr) has doubled. This has increased Nr in aquatic ecosystems, which can lead to reduced water quality and ecosystem health. Apportioning sources of Nr to specific ecosystems, however, continues to be challenging, despite this knowledge being critical for mitigation and protection of water resources. Here we use D17O, d18O and d15N from Uinta Mountain (Utah, USA) snow, inflow and lake nitrate in combination with a Bayesian-based stable isotope mixing model, to show that at least 70% of nitrates in aquatic systems are anthropogenic …
Climate, Ecology, And Human Evolution During The Plio-Pleistocene, Scott Adam Blumenthal
Climate, Ecology, And Human Evolution During The Plio-Pleistocene, Scott Adam Blumenthal
Dissertations, Theses, and Capstone Projects
A major goal of paleoanthropology is to identify the selective pressures associated with hominin biological and behavioral evolution, yet establishing cause-effect relationships between climate, ecology, and human evolution remains problematic. This dissertation seeks to investigate hominin paleoecology in eastern Africa by reconstructing aspects of climate and ecology using stable isotope analysis.
The first part of this dissertation is focused on the ecology of primates and hominins. Modern tropical African ecosystems provide a useful model for understanding the ecological correlates of isotopic variation in the fossil record, and living primates provide a useful model for understanding the ecological significance of isotopic …
Processes Controlling Carbon Cycling In Antarctic Glacier Surface Ecosystems, Elizabeth A. Bagshaw, Martyn Tranter, Jemma L. Wadham, Andrew G. Fountain, A. Dubnick, S. Fitzsimons
Processes Controlling Carbon Cycling In Antarctic Glacier Surface Ecosystems, Elizabeth A. Bagshaw, Martyn Tranter, Jemma L. Wadham, Andrew G. Fountain, A. Dubnick, S. Fitzsimons
Geology Faculty Publications and Presentations
Glacier surface ecosystems, including cryoconite holes and cryolakes, are significant contributors to regional carbon cycles. Incubation experiments to determine the net production (NEP) of organic matter in cryoconite typically have durations of 6-24 hours, and produce a wide range of results, many of which indicate that the system is net heterotrophic. We employ longer term incubations to examine the temporal variation of NEP in cryoconite from the McMurdo Dry Valleys, Antarctica to examine the effect of sediment disturbance on system production, and to understand processes controlling production over the lifetimes of glacier surface ecosystems. The shorter-term incubations have durations of …
Source Apportionment Of Atmospheric Particulate Matter In Developing Countries Using Trace Elements And Stable Metal Isotope Ratios, Nitika Dewan
Electronic Theses and Dissertations
The work presented herein details the source apportionment of atmospheric particulate matter in developing countries (Kyrgyzstan in Central Asia, metropolitan cities in Northern India, and Shenzhen in China) using trace elements and stable metal isotope ratios. The first study focused on the development of a novel method for the concomitant separation of rare-earth elements in environmental samples of any geological origin. The separation procedure is based on three extraction chromatographic materials, referred to as Sr.Spec, TRU.Spec, and Ln.Spec. This triple column arrangement enables the simultaneous isolation of pure Sr and Nd fractions in less than one day and with great …
Diffuse Co2 Degassing And The Origin Of Volcanic Gas Variability From Rincón De La Vieja, Miravalles And Tenorio Volcanoes, Guanacaste Province, Costa Rica, Aurelia Liegler
Dissertations, Master's Theses and Master's Reports
Volcanic gas emissions are an important key component for monitoring volcanic activity and magmatic input of carbon dioxide into the atmosphere as well as the assessment of geothermal potential in volcanic regions. Diffuse soil degassing of CO2 at Rincón de la Vieja and Miravalles volcanoes, assessed with the commonly accepted accumulation chamber method, showed the concentration of gas emissions in evident hydrothermal surface features in secondary gas emission zones of the volcanoes. Analyses of fumarolic gases were conducted to investigate similarities and differences between the volcanoes and the possibility of continued magma injection into their source(s). An output of …
Taxonomy, Location Of Origin, And Health Status Of Proboscideans From Western Canada Investigated Using Stable Isotope Analysis, Jessica Z. Metcalfe, Fred Longstaffe, Christopher N. Jass, Grant D. Zazula, Grant Keddie
Taxonomy, Location Of Origin, And Health Status Of Proboscideans From Western Canada Investigated Using Stable Isotope Analysis, Jessica Z. Metcalfe, Fred Longstaffe, Christopher N. Jass, Grant D. Zazula, Grant Keddie
Earth Sciences Publications
We investigated the application of stable isotope analysis of proboscidean remains (collagen in bone/dentin/cementum and structural carbonate in enamel bioapatite) for genus-level identification of isolated specimens, assessment of geographic origins, and testing for nutritional stress. Mammoths (Mammuthus sp.) tended to have higher δ15Ncol and lower δ13Ccol than mastodons (Mammut americanum), but differences were not significant in every location. Determining the genus of isolated specimens may be possible for locations and time periods with good isotopic baselines, but environmental changes can confound interpretations. For example, an Alberta proboscidean with a δ15N …
Formation Of The Neoarchean Bad Vermillion Lake Anorthosite Complex And Spatially Associated Granitic Rocks At A Convergent Plate Margin, Superior Province, Western Ontario, Canada, Shuda Zhou, Ali Polat, Fred Longstaffe, Kunguang Yang, Brian J. Fryer, Crhis Weisener
Formation Of The Neoarchean Bad Vermillion Lake Anorthosite Complex And Spatially Associated Granitic Rocks At A Convergent Plate Margin, Superior Province, Western Ontario, Canada, Shuda Zhou, Ali Polat, Fred Longstaffe, Kunguang Yang, Brian J. Fryer, Crhis Weisener
Earth Sciences Publications
The Bad Vermilion Lake Anorthosite Complex (henceforth, the BVLA Complex) in western Ontario is one of the well-exposed, anorthosite-bearing, Archean layered intrusions in the Superior Province, Canada. This study presents new whole-rock major and trace element data for the various units of the Complex, oxygen isotope data for the anorthosite, and major and trace element data for the spatially associated granitic rocks intruding the BVLA Complex to constrain their petrogenetic and geodynamic origin. Zircons from granitic rocks have yielded a 207Pb/206Pb age of 2716 ± 18 Ma, constraining the minimum intrusion age of the Complex. Despite deformation …
Precipitation And Growth Of Barite Within Hydrothermal Vent Deposits From The Endeavour Segment, Juan De Fuca Ridge, John William Jamieson, Mark D. Hannington, Margaret K. Tivey, Thor Hansteen, Nicole M.-B. Williamson, Margaret Stewart, Jan Fietzke, David Butterfield, Matthias Frische, Leigh Allen, Brian Cousens, Julia Langer
Precipitation And Growth Of Barite Within Hydrothermal Vent Deposits From The Endeavour Segment, Juan De Fuca Ridge, John William Jamieson, Mark D. Hannington, Margaret K. Tivey, Thor Hansteen, Nicole M.-B. Williamson, Margaret Stewart, Jan Fietzke, David Butterfield, Matthias Frische, Leigh Allen, Brian Cousens, Julia Langer
United States Department of Commerce: Staff Publications
Hydrothermal vent deposits form on the seafloor as a result of cooling and mixing of hot hydrothermal fluids with cold seawater. Amongst the major sulfide and sulfate minerals that are preserved at vent sites, barite (BaSO4) is unique because it requires the direct mixing of Ba-rich hydrothermal fluid with sulfate-rich seawater in order for precipitation to occur. Because of its extremely low solubility, barite crystals preserve geochemical fingerprints associated with conditions of formation. Here, we present data from petrographic and geochemical analyses of hydrothermal barite from the Endeavour Segment of the Juan de Fuca Ridge, northeast Pacific Ocean, …
Middle Preclassic Period Maya Greenstone "Triangulates": Forms, Contexts, And Geology Of A Unique Mesoamerican Groundstone Artifact Type, Terry G. Powis, Sherman Horn Iii, Gyles Iannone, Paul F. Healy, James F. Garber, Jaime J. Awe, Sheldon Skaggs, Linda A. Howie
Middle Preclassic Period Maya Greenstone "Triangulates": Forms, Contexts, And Geology Of A Unique Mesoamerican Groundstone Artifact Type, Terry G. Powis, Sherman Horn Iii, Gyles Iannone, Paul F. Healy, James F. Garber, Jaime J. Awe, Sheldon Skaggs, Linda A. Howie
Publications and Research
Over the past twenty years our understanding of the Middle Preclassic (900–300 BCE) period has become much clearer through archaeological investigations at a number of sites located in the Upper Belize River Valley region of the eastern Maya Lowlands. While the picture of Middle Preclassic Maya life, including their material culture, has sharpened, there are aspects that remain uninvestigated. One artifact type, identified as greenstone triangulates, has been found at several Belize Valley sites and in a variety of contexts. Although a number of these multifaceted, polished groundstone items have been recovered, little research has focused on their distribution and …
Comparison Of The Elemental Geochemistry Of The Arkansas Novaculite And The Boone Chert In Their Type Regions, Arkansas, J. Philbrick, E. Pollock, A. Potra
Comparison Of The Elemental Geochemistry Of The Arkansas Novaculite And The Boone Chert In Their Type Regions, Arkansas, J. Philbrick, E. Pollock, A. Potra
Journal of the Arkansas Academy of Science
The name Arkansas Novaculite was proposed by A.H. Purdue, 1909 to replace the name Arkansas Stone assigned by L. S. Griswold, 1892, but deemed too generic, to an interval of Early Devonian-Early Mississippian, very fine-grained, even textured, siliceous sedimentary rock famous for use as whetstones. The interval is exposed along the margins of the Benton Uplift, south flank of the Ouachita Mountains, west-central Arkansas, where it reaches a maximum thickness of 243.8 m (800 ft). The Arkansas Novaculite comprises informal lower and upper members characterized by massive beds of nearly pure novaculite, separated by a shale-bearing middle member that spans …
Dynamics Of Plume-Triple Junction Interaction: Results From A Series Of Three-Dimensional Numerical Models And Implications For The Formation Of Oceanic Plateaus, Mladen Dordevic, Jennifer Georgen
Dynamics Of Plume-Triple Junction Interaction: Results From A Series Of Three-Dimensional Numerical Models And Implications For The Formation Of Oceanic Plateaus, Mladen Dordevic, Jennifer Georgen
OES Faculty Publications
Mantle plumes rising in the vicinity of mid-ocean ridges often generate anomalies in melt production and seafloor depth. This study investigates the dynamical interactions between a mantle plume and a ridge-ridge-ridge triple junction, using a parameter space approach and a suite of steady state, three-dimensional finite element numerical models. The top domain boundary is composed of three diverging plates, with each assigned half-spreading rates with respect to a fixed triple junction point. The bottom boundary is kept at a constant temperature of 1350°C except where a two-dimensional, Gaussian-shaped thermal anomaly simulating a plume is imposed. Models vary plume diameter, plume …
Documenting Mantle And Crustal Contributions To Flood Basalt Magmatism Via Computational Modeling Of The Steens Basalt, Southeast Oregon, Sylvana J. Bendaña
Documenting Mantle And Crustal Contributions To Flood Basalt Magmatism Via Computational Modeling Of The Steens Basalt, Southeast Oregon, Sylvana J. Bendaña
All Master's Theses
Flood basalts are enormous volcanic events with volumes of volcanic cover and intrusive equivalents that are affected by and significantly affect the crust. Steens Basalt represents 31,800 km3 of flood basalt lavas that erupted in eastern Oregon ~16.8 Ma in less than 300,000 years. Analytical data of flows from a 1 km vertical exposure at Steens Mtn. documents time-transgressive changes in composition of two geochemically distinct units: (1) lower Steens, MgO-rich lavas with lower incompatible trace element concentrations and 87Sr/86Sr, and (2) upper Steens, MgO-poor, with higher incompatible trace element concentrations and 87Sr/86Sr. …
Sea Lamprey Mating Pheromone Registered By U.S. Environmental Protection Agency As First Vertebrate Pheromone Biopesticide, Marc Gaden, Marisa Lubeck
Sea Lamprey Mating Pheromone Registered By U.S. Environmental Protection Agency As First Vertebrate Pheromone Biopesticide, Marc Gaden, Marisa Lubeck
United States Geological Survey: Publications
Ann Arbor, MI – The U.S. Environmental Protection Agency registered a sea lamprey mating pheromone, 3kPZS, as the first ever vertebrate pheromone biopesticide in late December, 2015. Like an alluring perfume, the mating pheromone is a scent released by male sea lampreys to lure females onto nesting sites. Research and development of the mating pheromone was funded by the Great Lakes Fishery Commission, with additional support from the Great Lakes Restoration Initiative, in collaboration with federal government, university, and private industry partners.
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
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
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
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
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
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
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 ± …22>