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Full-Text Articles in Physical Sciences and Mathematics

Structural Analysis Of The Northwest Wind Mountain Quadrangle, New Mexico: Proterozoic Shearing To Cenozoic Brittle Faulting In The Burro Mountains, Jensen Kohl Angelloz Dec 2017

Structural Analysis Of The Northwest Wind Mountain Quadrangle, New Mexico: Proterozoic Shearing To Cenozoic Brittle Faulting In The Burro Mountains, Jensen Kohl Angelloz

Electronic Theses and Dissertations

Preliminary investigation of the Bullard Peak metamorphic series (BPMS) in the northwestern Wind Mountain quadrangle within the Burro Mountains of southwestern New Mexico suggests a possible previously unidentified shear zone, prompting detailed (1:12,000) geologic mapping and collection of structural data. The study area has a complex tectonic history, including 1) ~1.65 Ga metamorphism during accretion of the Mazatzal terrane to Laurentia’s southern margin; 2) ~1.4 Ga intrusion of Granite and Rhyolite Province granitoids; 3) significant uplift during the formation of the Ancestral Rockies (~300 Ma) and the Rocky Mountains (~70-50 Ma); and 4) inversion tectonics with reactivation of compressional faults …


Geology Of The Northern Alto Relex Area, Big Bend National Park, Brewster County, Texas, Robert Schoen Dec 2017

Geology Of The Northern Alto Relex Area, Big Bend National Park, Brewster County, Texas, Robert Schoen

Electronic Theses and Dissertations

Detailed, 1:12,000-scale geologic field mapping was conducted around Alto Relex in the northern Sierra Del Carmen Mountains in Big Bend National Park. Alto Relex is a prominent, near vertical, ~1000 foot-high fault-line scarp. Cretaceous rocks in the area were folded and faulted by Laramide compression, intruded by Tertiary sills and overprinted by high-angle normal faults from Basin and Range extension. During the Laramide Orogeny and Basin and Range extension, the underlying basement shear zone called, the Texas Lineament, was reactivated creating a transpressional and transtensional regimes. The general geology of this area was outlined by Moustafa (1988) working primarily from …


Evaluating Potential For Water Quality Decline In Maine Lakes, Kaci N. Fitzgibbon Dec 2017

Evaluating Potential For Water Quality Decline In Maine Lakes, Kaci N. Fitzgibbon

Electronic Theses and Dissertations

Understanding lake vulnerability with respect to eutrophication and loss of water quality is important for sustainability of aquatic ecosystems. This project aims at identifying and quantifying the effects of relevant physiochemical, climate, and watershed characteristics on lake vulnerability in order to develop management decision tools for the Maine Department of Environmental Protection (MEDEP). In a changing chemical and physical environment, using independent variables from each of these categories and then relating them to the summer lake epilimnetic phosphorus (P) concentrations allows for development of models to inform stakeholders of lake vulnerability to eutrophication problems.

We studied 24 lakes covering a …


Geological Framework Of The Continental Shelf Of South Carolina Winyah Bay: Paleodrainage, Transgressions And Essential Fish Habitat, Amanda Roach Dec 2017

Geological Framework Of The Continental Shelf Of South Carolina Winyah Bay: Paleodrainage, Transgressions And Essential Fish Habitat, Amanda Roach

Electronic Theses and Dissertations

A regional geophysical survey of the inner continental shelf off central South Carolina was completed on a cooperative cruise between NOAA and Coastal Carolina University in July 2015. An integrated mapping suite comprised of subbottom echosounder, side scan, multibeam and split beam sonars was used to define the regional geologic framework, including paleodrainage patterns across the shelf and to identify potential fish habitat locations that will provide additional inputs to a thematic habitat mapping routine developed by NOAA. Results from the thematic mapper characterization suggest that large-scale framework elements such as paleochannel networks may play a role in determining benthic …


Geophysical Delineation Of Megaporosity And Fluid Migration Pathways For Geohazard Characterization Within The Delaware Basin, Culberson County, Texas, Jonathan David Woodard Dec 2017

Geophysical Delineation Of Megaporosity And Fluid Migration Pathways For Geohazard Characterization Within The Delaware Basin, Culberson County, Texas, Jonathan David Woodard

Electronic Theses and Dissertations

ABSTRACT

Differential dissolution of gypsum karst within the Delaware Basin poses a significant threat to infrastructure that society depends on. The study area is located in Culberson County, Texas and traverses a distance of approximately 54 kilometers along RM 652 within the Gypsum Plain which is situated on the northern margin of the Chihuahua Desert and includes outcrops of Castile and Rustler strata that host karst geohazards. Regions of karst geohazard potential have been physically surveyed proximal to the study area in evaporites throughout the Castile Formation outcrop; minimal hazards, in comparison to the Castile Formation, have been documented in …


The Sequence Stratigraphic Context Of Mixed Basin Margin Evaporites In The Harrisburg Member Of The Permian Kaibab Formation, Northern Arizona And Southern Utah, Cole Hendrickson Nov 2017

The Sequence Stratigraphic Context Of Mixed Basin Margin Evaporites In The Harrisburg Member Of The Permian Kaibab Formation, Northern Arizona And Southern Utah, Cole Hendrickson

Electronic Theses and Dissertations

The Kaibab Formation is a mixed carbonate system including evaporites and siliciclastics deposited on a westward dipping epeiric carbonate ramp during the middle Permian in northern Arizona, southern Utah, and eastern Nevada. It consists of the Fossil Mountain Member deposited in open-marine conditions and the overlying Harrisburg Member deposited in restricted conditions. The Harrisburg Member includes facies and depositional environments ranging from open-marine shallow-subtidal wackestone - packstone, restricted subtidal dolomitic mudstone, dolomitic sandstone, peritidal oolitic grainstone as well as gypsum and red siltstones deposited in a sabkha environment.

Fourteen stratigraphic sections were measured across northern Arizona and southern Utah to …


In Situ Dating Of Multiple Events In Granulite-Facies Rocks Of The Larsemann Hills, Prydz Bay, East Antarctica Using Electron Microprobe Analysis Of Monazite, Steven K. Spreitzer Aug 2017

In Situ Dating Of Multiple Events In Granulite-Facies Rocks Of The Larsemann Hills, Prydz Bay, East Antarctica Using Electron Microprobe Analysis Of Monazite, Steven K. Spreitzer

Electronic Theses and Dissertations

The metamorphic rocks exposed along the southeast coast of Prydz Bay were affected by several metamorphic and plutonic events associated with collision in the Neoproterozoic and Cambrian. Critical units exposed in the Larsemann Hills and nearby ice-free areas include (1) basement Søstrene Orthogneiss, (2) cover sequence Brattstrand Paragneiss and (3) anatectic pegmatites intrusive into the Brattstrand Paragneiss. Zircon U-Pb data from previous studies yielded a maximum depositional age of 1023 ± 19 Ma for the Brattstrand Paragneiss, but only approximate ca. 900 Ma to ca. 1000 Ma and ca. 530 Ma ages for two metamorphic events. In order to constrain …


Vulnerability Assessment Of Groundwater To No3 Contamination Using Gis, Drastic Model And Geostatistical Analysis, Adela Beauty Adu Agyemang Aug 2017

Vulnerability Assessment Of Groundwater To No3 Contamination Using Gis, Drastic Model And Geostatistical Analysis, Adela Beauty Adu Agyemang

Electronic Theses and Dissertations

The study employed Geographical Information System (GIS) technology to investigate the vulnerability of groundwater to NO3 content in Buncombe County, North Carolina in two different approaches. In the first study, the spatial distribution of NO3 contamination was analyzed in a GIS environment using Kriging Interpolation. Cokriging interpolation was used to establish how NO3 relates to land cover types and depth to water table of wells in the county. The second study used DRASTIC model to assess the vulnerability of groundwater in Buncombe County to NO3 contamination. To get an accurate vulnerability index, the DRASTIC parameters were …


Groundwater Flow Tracing In Carter Saltpeter Cave And Toll Branch, Carter County, Tn, Aaron G. Doyka Aug 2017

Groundwater Flow Tracing In Carter Saltpeter Cave And Toll Branch, Carter County, Tn, Aaron G. Doyka

Electronic Theses and Dissertations

Groundwater tracing studies have shown a well-developed conduit system in the karst aquifer beneath the Buffalo Creek Watershed of Carter County, TN. Groundwater can quickly travel beneath topographic divides, transporting contaminants. Using GIS and field reconnaissance, two sites were selected for a two phase dye trace study. In May-June 2016 groundwater resurgences were located using activated carbon samplers, and in October-December 2016 flow velocities were measured using ISCO automatic water samplers. In study 1, a stream sinking in the back of Carter Saltpeter Cave was traced to its resurgence at Cave Springs Cave. In study 2, the dye mass centroid …


Constraining The Spatial Extent Of Strain Localization At The Base Of The Seismogenic Zone: A Case Study From The Sandhill Corner Shear Zone, Maine, Usa, Erik Kristian Anderson Jul 2017

Constraining The Spatial Extent Of Strain Localization At The Base Of The Seismogenic Zone: A Case Study From The Sandhill Corner Shear Zone, Maine, Usa, Erik Kristian Anderson

Electronic Theses and Dissertations

Knowledge of the structure and processes of strain localization at the base of the seismogenic zone can provide constraints on the rheologic evolution of shear zones at depth and the spatial extent that seismicity influences the surrounding rock. Such knowledge is hindered by limitations of borehole measurements from such depths and a lack of structural/mineralogical preservation of original rock fabric. The Sandhill Corner Shear Zone, Maine, USA provides an opportunity to study well-preserved structures relating to strain localization along major faults exhumed from seismogenic depths. In south-central Maine, this shear zone juxtaposes two rock types: the Cape Elizabeth Formation and …


Gravitational Study Of The Hastings Salt Dome And Associated Faults In Brazoria And Galveston Counties,Texas, Francis C. Okocha May 2017

Gravitational Study Of The Hastings Salt Dome And Associated Faults In Brazoria And Galveston Counties,Texas, Francis C. Okocha

Electronic Theses and Dissertations

Salt domes are important geological structures because they are potential major hydrocarbon traps and have a profound effect on overlying strata in the subsurface. Over five hundred salt domes have been located on the United States Gulf Coast region, including the Hastings Salt Dome. Hastings Oil Field is located about 40.2 km (25 miles) southeast of Houston, Texas. The Hasting oil field was discovered in 1934 and it was considered the largest oil reserve on the Gulf Coast. Its peak production of 75,000 BOPD (barrels of oil per day) was recorded in 1977 and it had a cumulative production of …


Structural And Stratigraphic Reconstruction Of The Whiting Dome Salt Structure In Viosca Knoll-Mississippi Canyon, Gom, Using 3d Seismic Data, Matthew R. Worrell May 2017

Structural And Stratigraphic Reconstruction Of The Whiting Dome Salt Structure In Viosca Knoll-Mississippi Canyon, Gom, Using 3d Seismic Data, Matthew R. Worrell

Electronic Theses and Dissertations

Understanding the complexities of salt tectonics is one of the most important factors regarding seismic interpretation of stratigraphy, structure, and geomorphology in the Gulf of Mexico. Evaluating the processes affecting recent mobilization of salt in the shallow, well-imaged section can help provide analogues for older, similar occurrences in the deeper section, thereby providing structural models for the autochthonous salt and its effect on stratigraphy and even potential timing and migration issues of hydrocarbons.

Progradation of delta front and shelf to slope transitional sediments has expulsed and emplaced an allochthonous salt structure (Whiting Dome) in the Viosca Knoll and Mississippi Canyon …


Influence Of Common Bean (Phaseolus Vulgaris) Grown In Elevated Co2 On Apatite Dissolution, Brian Matthew Morra May 2017

Influence Of Common Bean (Phaseolus Vulgaris) Grown In Elevated Co2 On Apatite Dissolution, Brian Matthew Morra

Electronic Theses and Dissertations

Elevated concentrations of atmospheric CO2 brought about by human activity creates changes in plant morphology, growth rate and exudate production. Our study sought to understand the effect of these changes on soil mineral weathering using plants grown under two conditions, ambient CO2 (400ppm) and elevated CO2 (1000ppm). Phaseolus vulgaris (common beans) were grown in flow-through microcosms consisting of a mixture of quartz and apatite sands. Plant growth was sustained by a nutrient solution devoid of calcium (Ca) and phosphorous (P). Using Atomic Adsorption Spectroscopy and colorimetry, Ca and P content of the leachate and plant tissue served …


Cranial Morphological Distinctiveness Between Ursus Arctos And U. Americanus, Benjamin James Hillesheim May 2017

Cranial Morphological Distinctiveness Between Ursus Arctos And U. Americanus, Benjamin James Hillesheim

Electronic Theses and Dissertations

Despite being separated by millions of years of evolution, black bears (Ursus americanus) and brown bears (Ursus arctos) can be difficult to distinguish based on skeletal and dental material alone. Complicating matters, some Late Pleistocene U. americanus are significantly larger in size than their modern relatives, obscuring the identification of the two bears. In the past, fossil bears have been identified based on differences in dental morphology or size. This study used geometric morphometrics to look at overall differences in cranial shape and used step-wise discriminant analysis to identify specific characters that distinguish cranial morphology between …


Basement And Cover Structural Analysis Along The Eagle River Gorge, Sawatch Range, Colorado, Kaitlin Lee Askelson May 2017

Basement And Cover Structural Analysis Along The Eagle River Gorge, Sawatch Range, Colorado, Kaitlin Lee Askelson

Electronic Theses and Dissertations

The Sawatch Range within the Rocky Mountains of central Colorado exposes Paleoproterozoic basement and overlying Paleozoic sedimentary rocks with a complex history of ductile and brittle deformation.

The goal of this study is to conduct analyses of brittle structures that occur in the basement and cover units to determine geometric relationships between the structures, provide a detailed description of structures and refine a geologic history for structures along the basement-cover contact in the northeastern Sawatch Range along the Eagle River canyon and U.S. Highway 24 from Red Cliff to Gilman, Colorado. Paleoproterozoic basement rocks include the Cross Creek granite, diorites, …


Spatiotemporal Analyses Of Recycled Water Production, Jana E. Archer May 2017

Spatiotemporal Analyses Of Recycled Water Production, Jana E. Archer

Electronic Theses and Dissertations

Increased demands on water supplies caused by population expansion, saltwater intrusion, and drought have led to water shortages which may be addressed by use of recycled water as recycled water products. Study I investigated recycled water production in Florida and California during 2009 to detect gaps in distribution and identify areas for expansion. Gaps were detected along the panhandle and Miami, Florida, as well as the northern and southwestern regions in California. Study II examined gaps in distribution, identified temporal change, and located areas for expansion for Florida in 2009 and 2015. Production increased in the northern and southern regions …


Late Quaternary Dragon Lizards (Agamidae: Squamata) From Western Australia, Julie Rej May 2017

Late Quaternary Dragon Lizards (Agamidae: Squamata) From Western Australia, Julie Rej

Electronic Theses and Dissertations

Fossil Agamidae from Western Australia have been the subject of limited study. To aid in fossil agamid identification, Hocknull (2002) examined the maxilla and dentary of several extant species from Australia and determined diagnostic characters for various species groups. In the study here, fossil agamids from two localities in Western Australia, Hastings Cave and Horseshoe Cave, were examined, grouped, and identified to the lowest unambiguous taxonomic level. Morphometric analyses were conducted to compare morphotypes, and find additional diagnostic characters. From Hastings Cave there were two maxilla morphotypes and three dentary morphotypes. Based on identifications, taxa present at this locality were …


An Analysis Of The Relationship Between Snowpack And Groundwater Across Utah Watersheds., Samuel Wright May 2017

An Analysis Of The Relationship Between Snowpack And Groundwater Across Utah Watersheds., Samuel Wright

Electronic Theses and Dissertations

This thesis examined what type of relationship existed between snow water equivalence (SWE) volume and groundwater elevation within six sub-watersheds in Utah. Data was gathered on SWE from seventeen SNOTEL sites and groundwater elevation data was gathered from six continuously monitored groundwater wells. This data was gathered for January through May for 2011, 2013, and 2014 in order to represent the water conditions that were above average, below average, and average respectively. Using MLR formulas the total SWE for each sub-watershed was determined for each year/month. Afterwards a correlation analysis was performed to determine if any association existed between SWE …


Black Bears (Ursus Americanus) Versus Brown Bears (U. Arctos): Combining Morphometrics And Niche Modeling To Differentiate Species And Predict Distributions Through Time, Theron Michael Kantelis May 2017

Black Bears (Ursus Americanus) Versus Brown Bears (U. Arctos): Combining Morphometrics And Niche Modeling To Differentiate Species And Predict Distributions Through Time, Theron Michael Kantelis

Electronic Theses and Dissertations

Late Pleistocene American black bears (Ursus americanus) often overlap in size with Pleistocene brown bears (U. arctos), occasionally making them difficult to diagnose. Large U. americanus have previously been distinguished from U. arctos by the length of the upper second molar (M2). However, the teeth of fossil U. americanus sometimes overlap size with U. arctos. As such, there is need for a more accurate tool to distinguish the two species. Here, 2D geometric morphometrics is applied to the occlusal surface of the M2 to further assess the utility of this tooth for distinguishing U. americanus and …


Delineation Of Karst Geohazards Along Rm 652 Through The Use Of Ground Penetrating Radar: Culberson County, Texas, Aaron A. Eaves Feb 2017

Delineation Of Karst Geohazards Along Rm 652 Through The Use Of Ground Penetrating Radar: Culberson County, Texas, Aaron A. Eaves

Electronic Theses and Dissertations

The Delaware Basin is the western member of the larger Permian Basin, and is located in the Trans-Pecos region of Texas and New Mexico. The Delaware Basin hosts significant evaporite karst geohazards throughout the Gypsum Plain of the Castile Formation, where geohazards of all scales form beneath and immediately adjacent to major infrastructure throughout the region, especially Ranch-to-Market 652, including geohazards ranging from small scale dissolution of road base, to large scale cave and sinkhole development. Gypsum sourced from the Castile and Rustler formations was used to create the road base of this RM652 , which meteoric waters have easily …


The Tuscaloosa Marine Shale: Geologic History, Depositional Analysis, And Exploration Potential, Jessica D. Pair Feb 2017

The Tuscaloosa Marine Shale: Geologic History, Depositional Analysis, And Exploration Potential, Jessica D. Pair

Electronic Theses and Dissertations

The Tuscaloosa Marine Shale (TMS) was deposited across southern Louisiana and Mississippi during the Upper Cretaceous. The study focuses on a core region containing vast deposits of Cretaceous-aged sediments that have economic importance for oil and gas exploration. This region has been conventionally drilled for decades, focusing on the recovery of the Cretaceous hydrocarbons. Explorers within this region had traditionally targeted the massive sand units of the Lower and Upper Tuscaloosa Group while neglecting the middle Tuscaloosa Marine Shale unit. With the onset of unconventional drilling technology, new explorers to the region have begun to delineate the Tuscaloosa Marine Shale’s …


Characterizing Coastal Marsh Groundwater Hydrology With Multichannel Electrical Resistivity Tomography, Matthew R. Kestner Jan 2017

Characterizing Coastal Marsh Groundwater Hydrology With Multichannel Electrical Resistivity Tomography, Matthew R. Kestner

Electronic Theses and Dissertations

Subsurface waters are highly enriched in nutrients compared to surface waters in the coastal salt marsh environment and may, therefore, have a large effect on biogeochemical processes. There have been numerous studies examining marsh platform hydrology, however, there is a lack of information on the hyporheic zone within tidal creeks in coastal salt marsh environments. Hyporheic exchange has been studied in various non-tidal freshwater systems and verified as a significant pathway for solute transport in typical stream settings. The total volume of water cycled through salt marsh tidal creek hyporheic zones could prove to be a significant component of the …


Paleodrainage Insights Into The Fluvial And Glacial History Of The Western Chukchi Margin, Arctic Alaska, Brittany A. Stockmaster Jan 2017

Paleodrainage Insights Into The Fluvial And Glacial History Of The Western Chukchi Margin, Arctic Alaska, Brittany A. Stockmaster

Electronic Theses and Dissertations

Chirp subbottom data collected from the Chukchi shelf, offshore of northwest Alaska, revealed extensive paleodrainage networks that incised the margin during sea level lowstands. These features are cut into folded Cretaceous bedrock strata and represent multiple sea level cycles. Several large incised valleys, 10s of km wide and up to 54 m deep, as well as numerous smaller, individual channels were identified. Sources of fluvial input include several, smaller rivers on the northwest Alaskan coast, such as the Kokolik, Kuk, Kukpowruk, and the Utukok Rivers. Correlation of sediment infill patterns provided insight to paleochannels and paleovalleys as well as outlined …


Impacts Of Landscape Position And Nitrogen Fertilizer On Soils, Carbon And Nitrogen Leaching, And Greenhouse Gas Fluxes From Switchgrass Production In South Dakota, Liming Lai Jan 2017

Impacts Of Landscape Position And Nitrogen Fertilizer On Soils, Carbon And Nitrogen Leaching, And Greenhouse Gas Fluxes From Switchgrass Production In South Dakota, Liming Lai

Electronic Theses and Dissertations

Switchgrass (Panicum virgatum L.) production for biofuels has potential economic values. It can also improve soil properties and perform better under marginal lands than the other major biomass crops. However, little is known about its potential ecological impacts assessed in terms of soils, water, and air quality in the northern Great Plains region of United States of America. The objectives of this study were to (i) evaluate the impacts of nitrogen fertilization rate (N rate) and landscape position on soil pH, soil organic carbon (SOC), total nitrogen (TN), bulk density (ρb), and phosphorus (P) in switchgrass field; (ii) assess …


Interactive Effects Of Cover Crops, Invertebrate Communities And Soil Health In Corn Production Systems, Claire Lacanne Jan 2017

Interactive Effects Of Cover Crops, Invertebrate Communities And Soil Health In Corn Production Systems, Claire Lacanne

Electronic Theses and Dissertations

The adoption of regenerative farming practices is gaining traction, but the costs and benefits are not often considered on a systems level. Encouraging biodiversity and soil health is the goal of many agricultural practices used in regenerative farming; regenerative systems employ practices which abide by the two main principles of increasing biodiversity and decreasing disturbance, with the goal of encouraging ecosystem functioning to minimize inputs and maximize the productivity of a farm. I examined the management of corn (Zea mays) fields across four states in the Upper Midwest region of the United States. Regenerative systems in this study …


Response Of Soil Properties To 23-25 Years Of Diverse Crop Rotations And Tillage Systems In South Dakota, Usa, Abdullah H. Alhameid Jan 2017

Response Of Soil Properties To 23-25 Years Of Diverse Crop Rotations And Tillage Systems In South Dakota, Usa, Abdullah H. Alhameid

Electronic Theses and Dissertations

Diverse cropping systems and no-till (NT) are beneficial in improving soil organic carbon (SOC) and other soils properties. The present study was conducted to evaluate the interactions and impacts of long-term tillage and diverse crop rotation systems on soil quality indicators that include a range of soil chemical, physical, hydrological, and microbial properties. The study was established in 1991 at Beresford, South Dakota and included three crop rotation systems [2-yr; maize (Zea mays L.)-soybean (Glycine max L.), 3-yr; maize-soybean-oat (Avena sativa L.), and 4-yr; maize-soybean-oat-wheat (Triticum aestivum L.)] managed under two tillage systems (NT and CT; conventional- tillage). Soil sampling …


Soil Response To Cropping Sequences And Grazing Under Integrated Crop-Livestock System, Hanxiao Feng Jan 2017

Soil Response To Cropping Sequences And Grazing Under Integrated Crop-Livestock System, Hanxiao Feng

Electronic Theses and Dissertations

Integrated crop-livestock system (ICLS) is helpful in diversifying a farm for improving its long-term sustainability and economic benefits. In the United States, the ICLS has been increasing in recent years because of its economic and environmental benefits. However, the impacts of ICLS on soil quality is not well documented in North Dakota. The objective of our study is to assess the impacts of cropping sequences and cattle grazing on the selected soil properties in the crop diversity and livestock integration practice. This study site was established in 2010 at the Dickinson Research Extension Center, Dickinson, North Dakota. The study design …


Impacts Of Integrated Crop-Livestock System On Soil Surface Greenhouse Gas Fluxes At A Farm Scale In South Dakota, Brant Douville Jan 2017

Impacts Of Integrated Crop-Livestock System On Soil Surface Greenhouse Gas Fluxes At A Farm Scale In South Dakota, Brant Douville

Electronic Theses and Dissertations

Grazing and cover crops (CC) can impact soil nutrient cycling but may increase the greenhouse gas (GHG) emissions from soils. However, little is known about their impacts on soil properties and soil surface GHG emissions in an integrated crop-livestock system (ICLS) in South Dakota, USA. The present study was conducted at a farm scale at the Research Farm of South Dakota State University, Brookings, South Dakota, to assess the impact of cover crops and grazing on soil pH, electrical conductivity (EC), and bulk density (BD), and soil surface carbon dioxide (CO2), methane (CH4), and nitrous oxide …


Impacts Of Crop Residue And Cover Crops On Soil Hydrological Properties, Soil Water Storage And Water Use Efficiency Of Soybean Crop, Kopila Subedi-Chalise Jan 2017

Impacts Of Crop Residue And Cover Crops On Soil Hydrological Properties, Soil Water Storage And Water Use Efficiency Of Soybean Crop, Kopila Subedi-Chalise

Electronic Theses and Dissertations

Cover crops and crop residue play a multifunctional role in improving soil hydrological properties, soil water storage and water use efficiency (WUE). This study was conducted to better understand the role of crop residue and cover crop on soil properties and soil water dynamics. The study was conducted at the USDA-ARS North Central Agricultural Research Laboratory, located in Brookings, South Dakota. Two residue removal treatments that include low residue removal (LRR) and high residue removal (HRR) were established in 2000 with randomized complete block design under no-till corn (Zea mays L.) and soybean (Glycine max L.) rotation. In 2005, cover …


Detection Of Sedimentary Depositional Cycles In The Salado Formation, Southeastern New Mexico, Scott Paul Milo Jan 2017

Detection Of Sedimentary Depositional Cycles In The Salado Formation, Southeastern New Mexico, Scott Paul Milo

Electronic Theses and Dissertations

An abundance of evaporitic features is preserved throughout the approximately 2,000-foot-thick Salado formation that is present across west Texas and southeastern New Mexico. The formation and preservation of evaporitic features are largely influenced by hydrology, and so those found in the Salado represent an uninterrupted record of hydrogeologic conditions in what is now the southwestern United States during the late Permian. Because it is home to the Waste Isolation Pilot Plant (WIPP) repository chamber, the salado has been the subject of countless studies ranging from areas of sedimentology, to geochemistry, to geotechnical engineering, to hydrology. However, until now there have …