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Articles 211 - 240 of 441
Full-Text Articles in Geology
Stratigraphic Reconstruction Of A Late Pleistocene Bald Cypress Forest Discovered On The Northern Gulf Of Mexico Continental Shelf, Suyapa Michell Gonzalez Rodriguez
Stratigraphic Reconstruction Of A Late Pleistocene Bald Cypress Forest Discovered On The Northern Gulf Of Mexico Continental Shelf, Suyapa Michell Gonzalez Rodriguez
LSU Master's Theses
A previously buried bald cypress forest (Taxodium distichum) was discovered on the continental shelf, offshore of Orange Beach, Alabama, USA, in ~20 m water depth. The forest was exhumed by Hurricane Ivan in 2004, and is now exposed as stumps in life position in a trough located in the northern Gulf of Mexico continental shelf seafloor. We are investigating the local stratigraphy, paleo-landscape, and mode of forest preservation of this unique site. In August 2015 and July 2016, submersible vibracores (18 in total) were collected. Core analysis included: bulk density and imaging via Geotek multi sensor core logger, …
Prospecting For Coal Bed Uranium In Kansas Through The Use Of Arcgis And Uranium Proxies, Logan Howell
Prospecting For Coal Bed Uranium In Kansas Through The Use Of Arcgis And Uranium Proxies, Logan Howell
Master's Theses or Doctor of Nursing Practice
The potential implications for the discovery of coal bed uranium in Kansas not only have a significant scientific and human health interest impact, but also a possible future economic one as well. This study sought to look for coal bed uranium within the Cretaceous Dakota Formation located in north-central of Kansas. This study utilized the two coal bed uranium proxies of historic subbituminous coal production and radon, and ArcGIS to produce a field-site selection map. This map was used to pick counties within Kansas to collect samples from. Once samples were collected, they were scanned for radiation using all available …
Spatial Patterns Of Precipitation Trends In The Continental United States, 1950-2016, Shayne O'Brien
Spatial Patterns Of Precipitation Trends In The Continental United States, 1950-2016, Shayne O'Brien
Master's Theses or Doctor of Nursing Practice
Identifying trends in aspects of meteorology is becoming increasingly important to understanding how climate can be expected to change, and how those affected may plan contingencies. Analyzing spatial patterns of precipitation trends allows for associations to be discovered to better understand regional climatology. For this study, daily precipitation data were collected from The National Oceanic and Atmospheric Administration (NOAA) Global Historical Climate Network (GHCN) at stations across the continental United States, with selection based on distance from each other within a state, as well as percent completeness of observation data. Two stations per state were selected, with some exceptions for …
Characteristics Of The Mantle Flow System Beneath The Indochina Peninsula Revealed By Teleseismic Shear Wave Splitting Analysis, Youqiang Yu, Stephen S. Gao, Kelly H. Liu, Ting Yang, Mei Xue, Khanh Phon Le, Jinyao Gao
Characteristics Of The Mantle Flow System Beneath The Indochina Peninsula Revealed By Teleseismic Shear Wave Splitting Analysis, Youqiang Yu, Stephen S. Gao, Kelly H. Liu, Ting Yang, Mei Xue, Khanh Phon Le, Jinyao Gao
Geosciences and Geological and Petroleum Engineering Faculty Research & Creative Works
Numerous geoscientific investigations have been conducted on the southeastern Tibetan Plateau and adjacent areas for understanding crustal and mantle deformation associated with the indentation of the Indian Plate into Eurasia. A number of key issues, such as the causes of a sudden change of fast polarization orientations from N-S to almost E-W at approximately 26°N revealed by shear wave splitting (SWS) studies, and the geodynamic implications of the transition still remain enigmatic, partially due to the lack of sufficient SWS measurements on the Indochina Peninsula. Here we employ the SWS technique to systematically illuminate upper mantle anisotropy beneath the Indochina …
Geology Of The Purgatory Saddle 7.5 Minute Quadrangle, And Gravity And Magnetic Analysis Of Accreted Terrane Boundary, Western Idaho, Sourav Krishna Nandi
Geology Of The Purgatory Saddle 7.5 Minute Quadrangle, And Gravity And Magnetic Analysis Of Accreted Terrane Boundary, Western Idaho, Sourav Krishna Nandi
Graduate Theses/Dissertations
Western Idaho (USA) contains deformation associated with the Mesozoic accretion of volcanic island arc terranes of the Blue Mountains Province to Laurentia. The near vertical boundary between the accretionary orogeny and Precambrian North America is represented by the transpressional western Idaho shear zone, which lies east of metamorphic rocks in the Salmon River suture zone. The Blue Mountains Province in western Idaho contains four accreted crustal blocks: the Wallowa, Olds Ferry, Baker, and Izee terranes. The purpose of this study is to understand the structural relationship of the pre-accretionary, syn-accretionary and post-accretionary tectonic features along the accreted terrane boundary in …
Regional Stratigraphy And Distribution Of The Coastal Group, St. Elizabeth Parish, Southwestern Jamaica, Brett M. Kenning
Regional Stratigraphy And Distribution Of The Coastal Group, St. Elizabeth Parish, Southwestern Jamaica, Brett M. Kenning
Graduate Theses/Dissertations
This contribution examines the characteristics and ages of sedimentary units in the Coastal Group located along the southwestern Jamaica coast between Great Pedro Bluff and Fort Charles Bay in southwestern St. Elizabeth Parish. The coastline is characterized by laterally discontinuous low cliff exposures, separated by modern beach deposits and tectonically raised shore platforms composed of the White Limestone Group (mid-Eocene to mid-Miocene) and coral rudstone to floatstone and calcareous sandstone of the Coastal Group (late Pleistocene). Electron-Spin Resonance spectroscopy conducted on corals collected from a coral rudstone to floatstone facies yielded an estimated age of 120 ka. The coral facies …
Interpretation And Fracture Characterization Of Early-Cretaceous Buda Limestone Formation Using Post-Stack 3d Seismic Data In Zavala County, Texas, Andrey Smirnov
Graduate Theses and Dissertations
The Buda Limestone is a naturally fractured Early Cretaceous carbonate formation in south Texas which unconformably underlies the Eagle Ford Shale. Matrix porosity of the Buda is less than 6%, therefore natural fractures improve the potential for commercial hydrocarbon production from this tight limestone formation. This presents a challenge for producers to identify these zones using well log and post stack 3D seismic data typically available to medium or small exploration companies. This project provides a workflow based on well log analysis tied to seismic acoustic impedance (AI) inversion to locate areas of probable natural fractures. Acoustic impedance inversion was …
Structural Cross Sections And Subsurface Maps Of The Atoka Formation In The Northern Arkoma Basin, Western And Northwestern Arkansas, David Nance
Graduate Theses and Dissertations
The Arkoma Basin is one of several peripheral foreland basins situated on the front of the Ouachita orogenic fold and thrust belt. The transition from the foredeep to the Ozark Plateaus is a short one in terms of latitude. The Atoka Formation in Arkansas comprises the bulk of the sediments in the Arkoma Basin. Three divisions of the Atoka Formation have been informally assigned as the Upper, Middle, and Lower based on differences in sedimentary response to tectonic processes that occurred during the formation and subsidence of the Arkoma Basin. In the Arkansas portion of the Arkoma Basin, the lower …
Gis Modeling Of The Prominent Geohazards In Arkansas, Kyle Walker Rowden
Gis Modeling Of The Prominent Geohazards In Arkansas, Kyle Walker Rowden
Graduate Theses and Dissertations
The State of Arkansas is prone to numerous geohazards. This thesis is a twofold study of prominent geohazards in Arkansas: the first fold includes a novel triggerless approach for mass wasting susceptibility modeling applied to the Boston Mountains in NW Arkansas, and the second fold is a GIS-based regression modeling of the extreme weather patterns at the state level. Each study fold is presented in this thesis as a separate chapter embracing a published peer-reviewed paper. In the first paper, I have used the analytical hierarchy process to assign preliminary statistical weights to the most cogent variables influencing mass wasting …
Understanding The Late Mesoproterozoic Earth System From The Oldest Strata In Grand Canyon: C-Isotope Stratigraphy And Facies Analysis Of The 1254 Ma Bass Formation, Grand Canyon Supergroup, Az., Usa, Erin C. Lathrop
All Graduate Theses and Dissertations, Spring 1920 to Summer 2023
Rocks provide insight into ancient times before complex animals existed. The oldest sedimentary rocks in Grand Canyon (the Bass Formation) allow us to glimpse into what things might have been like over a billion years ago. These rocks record the time known as the Mesoproterozoic Era (1.6 to 1.0 billion years ago), otherwise known as the ‘boring billion’. These rocks are thought to be the right age to indicate the end of an oddly stable world when continents were quiet and life was calm, yet they predate younger rocks that record extreme events. The Bass Formation, some of the only …
Quaternary Incision, Salt Tectonism, And Landscape Evolution Of Moab-Spanish Valley, Utah, James P. Mauch
Quaternary Incision, Salt Tectonism, And Landscape Evolution Of Moab-Spanish Valley, Utah, James P. Mauch
All Graduate Theses and Dissertations, Spring 1920 to Summer 2023
To study the history of processes that shape the Earth’s surface, geologists look for markers in the landscape that they can date and use to measure change. Rivers leave such markers in their deposits and terrace landforms and in the overall shape of their elevation profile from head to toe. This thesis uses luminescence and cosmogenic methods to date the sediment in terraces to determine when the river deposited it. Field mapping and global positioning system (GPS) surveying are also used to measure the distance between terrace levels to quantify how much change has occurred. This study seeks to answer …
Investigating Uranium Incorporation In Modern Carbonates By Sequential Extraction: Applied To The Permian - Triassic Boundary In Lung Cam, Vietnam, Christopher Michael Wray
Investigating Uranium Incorporation In Modern Carbonates By Sequential Extraction: Applied To The Permian - Triassic Boundary In Lung Cam, Vietnam, Christopher Michael Wray
LSU Master's Theses
The Uranium (U) isotopic system can be used to model the extent of global-scale ocean anoxia by utilizing the 238U/235U ratios as a paleo-redox indicator (δ238U). While recent studies have shown promise with the use of this novel proxy, variability is seen in modern carbonate sediment samples suggesting that more work is needed in order to understand elemental U uptake during early marine diagenesis. This thesis utilizes a sequential extraction methodology in order to understand the distribution of authigenic U within carbonate sediments.
This thesis consists of four parts, (1) an evaluation and modification of a sequential extraction methodology for …
Devonian Stromatoporoid Interactions At The Falls Of The Ohio State Park, Clarksville, Indiana, Morgan Sierra Hall
Devonian Stromatoporoid Interactions At The Falls Of The Ohio State Park, Clarksville, Indiana, Morgan Sierra Hall
Undergraduate Theses
Stromatoporoids are calcitic sponges that occurred in the fossil record from the Early Ordovician to Late Devonian period. These sponges interacted with other organisms, especially rugose and tabulate corals. Some corals appear to benefit from the rigidity of stromatoporoids in response to turbulent waters. Stromatoporoids and many corals went extinct during the Frasnian-Famennian crisis when paleoenvironmental parameters were shifting. Studying the relationships between these taxa may provide insight to their vulnerability during the extinction.
This research was performed at the Falls of the Ohio in Clarksville, Indiana. Organisms in the Coral Zone were studied using transect sampling. Each fossil along …
You Should Advocate For Science, Denise J. Hills, Daniel Horton, Rafael Loureiro, Kimberly Popendorf, Christine Marie Downs, Ronald E. Doel, Prabhakar Clement, Adam Kobelski
You Should Advocate For Science, Denise J. Hills, Daniel Horton, Rafael Loureiro, Kimberly Popendorf, Christine Marie Downs, Ronald E. Doel, Prabhakar Clement, Adam Kobelski
School of Geosciences Student Publications
Are you engaged in rigorous science? If so, ask your elected representatives to fund it robustly and predictably and to oppose policies that impede scientific progress.
Structural Classification Using Aeromagnetic Data And Pseudogravity Transforms: A Case Study Of Pategi Area Of Bida Basin, Nigeria, Ayodele K Olawuyi, Halima M Amir, Mkabwa Lk Manoko
Structural Classification Using Aeromagnetic Data And Pseudogravity Transforms: A Case Study Of Pategi Area Of Bida Basin, Nigeria, Ayodele K Olawuyi, Halima M Amir, Mkabwa Lk Manoko
Tanzania Journal of Science
The structural classification with 3D Euler deconvolution method in the Pategi area, a transition environment between the Basement complex rocks of the southwestern Nigeria and the Sedimentary rocks of the Nupe Basin was carried out. It was aimed at identification of the structural features responsible for the hydrogeology and mineralization potentials of the area. This work involves the qualitative and quantitative analysis of aeromagnetic data and pseudogravity transforms using Oasis MontajTM. The 3-D Euler deconvolution of the acquired aeromagnetic data and pseudogravity transforms using Oasis montajTM software and the geologic information on this area was employed in the structural classification …
Speciation Of Lead, Chromium, Cadmium, Copper And Zinc In Sediments And Plants Along Msimbazi River In Dar Es Salaam, Tanzania, Faustin N Ngassapa, Othman C Othman, David Mihayo, Kessy F Kilulya
Speciation Of Lead, Chromium, Cadmium, Copper And Zinc In Sediments And Plants Along Msimbazi River In Dar Es Salaam, Tanzania, Faustin N Ngassapa, Othman C Othman, David Mihayo, Kessy F Kilulya
Tanzania Journal of Science
The speciation of lead, chromium, cadmium, copper and zinc in sediments and plants (pumpkin) along Msimbazi River in Dar es Salaam were determined using Atomic Absorption Spectrophotometry. Results in sediments indicated that the heavy metal contents (mg/kg) in the form of total trace metals ranged from 50.34 to 161.63 for Pb, 68.38 to 501.85 for Zn, 18.43 to 66.61 for Cu, 20.93 to 76.46 for Cr and BDL to 0.23 for Cd. The contents (mg/kg) in the form of metals bound to organic matter ranged from 18.24 to 46.58 for Pb, 27.64 to 228.62 for Zn, 3.55 to 16.76 for …
Assessment Of Radioactivity Levels In Coal And Coal Ash In Kiwira Coal Mine Using Gamma-Ray Spectrometry, Ismael N Makundi, Mungubariki M Nyaki, Najat K Mohammed
Assessment Of Radioactivity Levels In Coal And Coal Ash In Kiwira Coal Mine Using Gamma-Ray Spectrometry, Ismael N Makundi, Mungubariki M Nyaki, Najat K Mohammed
Tanzania Journal of Science
This study aimed to assess the radioactivity levels and associated dose rates from the naturally occurring radionuclides 226Ra, 232Th and 40K in coal and coal ashes at Kiwira coal mine. The radioactivity of 40 representative coal, fly ash samples were measured using gamma spectroscopy of the Tanzania Atomic Energy Commission (TAEC) in Arusha, Tanzania. The activity concentrations of 226Ra, 232Th and 40K in coal and coal ashes from Kiwira were higher by several orders of magnitude than their worldwide average values. The calculated radium equivalent activity, the air absorbed dose rate, external hazard index and the average annual effective dose …
Predicting Stratigraphic Outcrops Using A Lidar Digital Elevation Model In A Karst Landscape, Fort Hood Military Installation, Texas, Keely Armstrong
Predicting Stratigraphic Outcrops Using A Lidar Digital Elevation Model In A Karst Landscape, Fort Hood Military Installation, Texas, Keely Armstrong
Undergraduate Research Conference
The Fort Hood Military Installation is a karst landscape characterized by Cretaceous-age limestone plateaus and canyons in Bell and Coryell counties, Texas. The area is located in the Lampasas Cut Plain region of the Edwards Plateau and is stratigraphically defined by exposures of the Fredericksburg Group, namely the Comanche Peak and Edwards carbonates. The topography is dominated by plateaued draining divides capped by the resistant Edwards limestone and bordered by steep scarps exposing alternating layers of the Comanche Peak and Edwards units. This interfingering relationship has created a variable slope along the edges of the plateaus, defined by lithology.
The …
Magmatism And Mass Extinction: Resolving The Flood Basalt Carbon Quandary, Benjamin Black
Magmatism And Mass Extinction: Resolving The Flood Basalt Carbon Quandary, Benjamin Black
Sustainability Seminar Series
Voluminous flood basalt magmatism has coincided with multiple biotic crises, including the end-Permian, end-Triassic, and end-Cretaceous mass extinctions and the Paleocene-Eocene Thermal Maximum. Geochemical evidence shows that warming and carbon cycle perturbation were features of each of these events. This proxy evidence is at odds with current estimates of the budget and isotopic composition of carbon in flood basalt magmas, which suggest that flood basalt magmatic carbon is inadequate and too isotopically heavy to explain the observations. To address the apparent conflict between paleoclimate and petrology, I present results from melt inclusions, carbonatites, geophysical modeling, and climate modeling to address …
Assessing Land Deformation And Sea Encroachment In The Nile Delta, Egypt, Esayas Gebremichael
Assessing Land Deformation And Sea Encroachment In The Nile Delta, Egypt, Esayas Gebremichael
Research and Creative Activities Poster Day
Persistent scatterer interferometric analyses were conducted on a stack of 84 Envisat ASAR scenes spanning 7 years (2004 to 2010) over the entire Nile Delta of Egypt and surroundings to monitor the ongoing spatial and temporal land deformation, identify the factors controlling the deformation, and model the interplay between sea level rise and land subsidence to identify areas and populations threatened by sea encroachment by the end of the 21st century. Findings include: (1) general patterns of subsidence in the northern delta, near-steady (none) subsidence in the southern delta, separated by a previously mapped flexure zone undergoing uplift; (2) high …
Spectral Analysis Of Surface Waves To Detect Subsurface Voids, Payman Hajiani, Neil Lennart Anderson, J. David Rogers
Spectral Analysis Of Surface Waves To Detect Subsurface Voids, Payman Hajiani, Neil Lennart Anderson, J. David Rogers
Geosciences and Geological and Petroleum Engineering Faculty Research & Creative Works
Systems and methods for detecting a subsurface cavity. A source applies a force to ground under inspection and a plurality of sensors coupled to the ground detect resulting surface waves. A processor is configured to extract phase and frequency components of the acquired seismic data, identify a phase shift in surface waves in the ground under inspection based on the extracted phase and frequency components, and determine one or more physical characteristics of a subsurface cavity based on the identified phase shift
Unusual Internal Structure Of Cm-Sized Coldwater Calcite: Weichselian Spars In Former Pools Of The Zinnbergschacht Cave (Franconian Alb/Se Germany), Detlev K. Richter, Rolf D. Neuser, Martin Harder, Hardy Schabdach, Denis Scholz
Unusual Internal Structure Of Cm-Sized Coldwater Calcite: Weichselian Spars In Former Pools Of The Zinnbergschacht Cave (Franconian Alb/Se Germany), Detlev K. Richter, Rolf D. Neuser, Martin Harder, Hardy Schabdach, Denis Scholz
International Journal of Speleology
The investigation of the internal structure of calcite crystals is a new focus in speleothem science, especially in the range of crystallization temperatures close to 0°C. Recently found calcite spars from Zinnbergschacht Cave of the Franconian Alb (SE Germany) are ideal for multi-method investigation. The elongated calcites (up to 6 cm in length) with three to six lateral faces and basal triangular faces at the ends are observed in collapse-zones in the cave. 230Th/U-ages of 38.9 ka suggest formation during the periglacial Weichselian, between the Scandinavian and Alpine Glaciations. The δ18O and δ13C values of …
Replication And Reinsertion Of Stalagmites Sampled For Paleoclimatic Purposes, Eleuterio Baeza, Rafael P. Lozano, Carlos Rossi
Replication And Reinsertion Of Stalagmites Sampled For Paleoclimatic Purposes, Eleuterio Baeza, Rafael P. Lozano, Carlos Rossi
International Journal of Speleology
Sampling stalagmites for paleoclimatic study can enter into conflict with preserving the beauty and integrity of caves. To minimize this impact, a variety of sampling strategies have been used by researches aware of cave-conservation issues. Based on our experience in two caves (El Soplao and La Buenita, Cantabria, N Spain), we propose to apply molding and casting laboratory techniques to create replicas of stalagmites, placing the replicas back in the original cave locations so that the impact of sampling to the cave is severely reduced. We provide detailed descriptions of the molding and casting methods, which vary depending on stalagmite …
Quantifying Knickpoint Behavior And Erosion Mechanisms In An Urbanized Watershed, Bull Mountain, Washington County, Oregon, Max Gregory Bordal
Quantifying Knickpoint Behavior And Erosion Mechanisms In An Urbanized Watershed, Bull Mountain, Washington County, Oregon, Max Gregory Bordal
Dissertations and Theses
Quantifying spatial and temporal patterns of rapid channelized erosion, on human time scales, is critical to understanding its processes and their consequences. This investigation utilized field observations, repeat terrestrial laser scanning (TLS), and Structure-from-Motion photogrammetry (SfM) to document the size and retreat rates of a knickpoint, defined as a localized near-vertical reach of a fluvial channel, and its contribution to erosion, in an urbanizing landscape with a loess substrate. The Bull Mountain area, in Washington County, southwest of Portland, Oregon, is an ideal study area, offering a measurable knickpoint that translates the response of the rapid erosion throughout this transient …
Using Repeat Terrestrial Laser Scanning And Photogrammetry To Monitor Reactivation Of The Silt Creek Landslide In The Western Cascade Mountains, Linn County, Oregon, Justin Craig Mccarley
Using Repeat Terrestrial Laser Scanning And Photogrammetry To Monitor Reactivation Of The Silt Creek Landslide In The Western Cascade Mountains, Linn County, Oregon, Justin Craig Mccarley
Dissertations and Theses
Landslides represent a serious hazard to people and property in the Pacific Northwest. Currently, the factors leading to sudden catastrophic failure vs. gradual slow creeping are not well understood. Utilizing high-resolution monitoring techniques at a sub-annual temporal scale can help researchers better understand the mechanics of mass wasting processes and possibly lead to better mitigation of their danger. This research used historical imagery analysis, precipitation data, aerial lidar analysis, Structure from Motion (SfM) photogrammetry, terrestrial laser scanning (TLS), and hydrologic measurements to monitor displacement of the Silt Creek Landslide in the western Cascade Mountain Range in Linn County, Oregon. This …
Areal Extent And Volumes Of The Dinner Creek Tuff Units, Eastern Oregon Based On Lithology, Bulk Rock Composition And Feldspar Mineralogy, Teresa Rae Hanna
Areal Extent And Volumes Of The Dinner Creek Tuff Units, Eastern Oregon Based On Lithology, Bulk Rock Composition And Feldspar Mineralogy, Teresa Rae Hanna
Dissertations and Theses
The Dinner Creek Tuff erupted during a period of rhyolitic volcanism coeval to the flood volcanism associated with the Columbia River Basalt Group. The High Rock Caldera Complex, Lake Owyhee and McDermitt volcanic fields account for ~90% of the rhyolites erupted between 16.7-15.0 Ma. Situated at the northern end of the Lake Owyhee volcanic field, the Dinner Creek Tuff was originally mapped as a ~2,000 km2 single ignimbrite confined to the Malheur Gorge. Streck et al. (2015) correlated tuff outcrops previously mapped as generic Miocene welded tuff as well as local units such as the "Mascall" or "Pleasant Valley" …
T.D.A. Cockerell (1866–1948) Of The University Of Colorado: His Contributions To The Natural History Of The California Islands And The Establishment Of Channel Islands National Monument, Daniel R. Muhs
United States Geological Survey: Staff Publications
Theodore Dru Alison Cockerell was a naturalist at the University of Colorado from 1904 to 1947 and studied botany, zoology, and paleontology in North and South America, Asia, Australia, Africa, and Europe. In the latter part of his career, he studied the California islands and published many papers on their natural history, 16 of them in four years (1937–1940). He made important contributions to the natural history of the islands in four distinct ways: entomology of the islands, including identification of a number of new species of bees; discovery of fossil marine invertebrate faunas and recognition that the zoogeography of …
Evaluation Of Academic And Social Engagement In A Technology-Based Collaborative Approach To Inclusive Geoscience Field Learning, Anita Marie Stone Marshall
Evaluation Of Academic And Social Engagement In A Technology-Based Collaborative Approach To Inclusive Geoscience Field Learning, Anita Marie Stone Marshall
USF Tampa Graduate Theses and Dissertations
Field learning is an important aspect of geoscience education to teach or reinforce concepts and skills, and the highly social experience of field work can improve learning outcomes, create networks to support future academic success, and promote a sense of belonging in the geosciences. However, field learning presents significant barriers to participation for students with physical disabilities. The introduction of digital data collection and communication devices into traditional field work settings has created new opportunities to expand access to field learning experiences such as remote collaboration; a method of undertaking field work through collaborative teamwork and the use of digital …
Microtextural Studies Of Feldspar In Ordinary Chondrites, Jonathan A. Lewis
Microtextural Studies Of Feldspar In Ordinary Chondrites, Jonathan A. Lewis
Earth and Planetary Sciences ETDs
Ordinary chondrites contain an important record of events that took place during the earliest period of solar system evolution. These include primary processes, such as chondrule formation, and secondary processes, those that affected asteroids after accretion and modified primary components. Secondary processes include aqueous alteration, thermal metamorphism, and shock effects from impact events. Secondary minerals can provide insight into the chemical and physical conditions that affected their parent asteroids. Feldspar is known to be a secondary mineral that crystallized during thermal metamorphism. The goal of this work is to use the formation and evolution of feldspar to elucidate the conditions …
Modeling Climate Change Impacts On Water Balance Components Of The Mackinaw River Watershed, Central Illinois, Joseph Honings
Modeling Climate Change Impacts On Water Balance Components Of The Mackinaw River Watershed, Central Illinois, Joseph Honings
Theses and Dissertations
Understanding the response of water cycle dynamics to climate change and human activity is essential for best management of water resources. This study used the USDA Soil-Water Assessment Tool (SWAT) to measure and predict major water balance variables including stream discharge, potential aquifer recharge, and surface storage in a small-scale watershed (~2,930 km²) in Central Illinois. The watershed is predominantly tile-drained agricultural land, which controls the nutrient dynamics and hydrology. Two reservoirs, Evergreen Lake and Lake Bloomington, and the Mahomet Aquifer in the watershed are used for public water supply. The subject watershed has been very sensitive to recent droughts, …