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Articles 421 - 437 of 437
Full-Text Articles in Geology
Water-Level And Recoverable Water In Storage Changes, High Plains Aquifer, Predevelopment To 2015 And 2013–15, Virginia L. Mcguire
Water-Level And Recoverable Water In Storage Changes, High Plains Aquifer, Predevelopment To 2015 And 2013–15, Virginia L. Mcguire
United States Geological Survey: Staff Publications
The High Plains aquifer underlies 111.8 million acres (about 175,000 square miles) in parts of eight States—Colorado, Kansas, Nebraska, New Mexico, Oklahoma, South Dakota, Texas, and Wyoming. Water-level declines began in parts of the High Plains aquifer soon after the beginning of substantial irrigation with groundwater in the aquifer area (about 1950). This report presents water-level changes and change in recoverable water in storage in the High Plains aquifer from predevelopment (about 1950) to 2015 and from 2013 to 2015.
The methods to calculate area-weighted, average water-level changes; change in recoverable water in storage; and total recoverable water in storage …
Key Differences Between Lakes And Reservoirs Modify Climate Signals: A Case For A New Conceptual Model, Nicole M. Hayes, Bridget R. Deemer, Jessica R. Corman, N. Roxanna Razavi, Kristin E. Strock
Key Differences Between Lakes And Reservoirs Modify Climate Signals: A Case For A New Conceptual Model, Nicole M. Hayes, Bridget R. Deemer, Jessica R. Corman, N. Roxanna Razavi, Kristin E. Strock
United States Geological Survey: Staff Publications
Lakes and reservoirs are recognized as important sentinels of climate change, integrating catchment and atmospheric climate change drivers. Climate change conceptual models generally consider lakes and reservoirs together despite the possibility that these systems respond differently to climate-related drivers. Here, we synthesize differences between lake and reservoir characteristics that are likely important for predicting waterbody response to climate change. To better articulate these differences, we revised the energy mass flux framework, a conceptual model for the effects of climate change on lentic ecosystems, to explicitly consider the differential responses of lake versus reservoir ecosystems. The model predicts that catchment and …
Shocked Quartz Distribution, Andrew Mason
Shocked Quartz Distribution, Andrew Mason
UCARE: Research Products
Shocked quartz is typically used to test if sites experienced a meteorite impact in the past, however, sediment is readily transported by both earthly and extraterrestrial processes that blur the lines of where impact sites are on earth. The specific deformations in the clasts themselves reveal much about their origin and present location.
Nebraska Statewide Groundwater-Level Monitoring Report 2016, Aaron R. Young, Mark E. Burbach, Leslie M. Howard, Michele M. Waszgis, R. Matthew Joeckel, Sue Olafsen Lackey
Nebraska Statewide Groundwater-Level Monitoring Report 2016, Aaron R. Young, Mark E. Burbach, Leslie M. Howard, Michele M. Waszgis, R. Matthew Joeckel, Sue Olafsen Lackey
Conservation and Survey Division: Faculty and Staff Publications
The term “groundwater” has come to be all but synonymous with Nebraska. Nearly three-quarters of the volume of the High Plains aquifer lies beneath the State, and groundwater maintains our streams, our ecosystems, our people, and our vitally important agricultural economy. Although Nebraska’s total groundwater resource is vast, it is also quite vulnerable to changes induced by natural processes and by humankind, necessitating a long-term commitment to wise management through informed decision making. Monitoring, studying, and reporting are the essential basis for such management and, ultimately, for meeting the myriad challenges presented by change.
The personnel of the Conservation and …
Geophysical Interpretation And Static Reservoir Modeling Of Structurally Complex Reservoir, Rg Oil Field Area, Sirte Basin, Libya, Abdalla A. Abdelnabi
Geophysical Interpretation And Static Reservoir Modeling Of Structurally Complex Reservoir, Rg Oil Field Area, Sirte Basin, Libya, Abdalla A. Abdelnabi
Doctoral Dissertations
"Cambrian-Ordovician and Upper Cretaceous reservoir formations are found in the central western Sirte Basin, the main oil producing region in the Sirte Basin, Libya. As a result of changes in sedimentary environments and structural activities, a number of irregularities in reservoir continuity have developed, which negatively affected the overall performance of the reservoir. Effective simulation of such complex reservoirs can be achieved by integrating geophysical, geological, and petrophysical data to construct a reliable full-field static model, which has the potential to simulate the vertical and lateral variations in the reservoir formations. In this study, 2D and 3D seismic data acquired …
Layered Crustal And Mantle Structure And Anisotropy Beneath The Afar Depression And Malawi Rift Zone, Cory Alexander Reed
Layered Crustal And Mantle Structure And Anisotropy Beneath The Afar Depression And Malawi Rift Zone, Cory Alexander Reed
Doctoral Dissertations
"Although a wealth of geophysical data sets have been acquired within the vicinity of continental rift zones, the mechanisms responsible for the breakup of stable continental lithosphere are ambiguous. Eastern Africa is host to the largest contemporary rift zone on Earth, and is thus the most prominent site with which to investigate the processes which govern the rupture of continental lithosphere. The studies herein represent teleseismic analyses of the velocity and thermomechanical structure of the crust and mantle beneath the Afar Depression and Malawi Rift Zone (MRZ) of the East African Rift System. Within the Afar Depression, the first densely-spaced …
Depositional Systems, Sequence Architecture, And Controlling Factors Of An Eocene Stratigraphic Sequence At Minfeng Steep Margin Of Dongying Depression, Eastern China, Zhixin Li
Doctoral Dissertations
“This study is carried out in Minfeng area, the steep margin of Dongying half graben, eastern China, by integrating 3-D seismic, wireline log, and core data, and aims to interpret the depositional systems, reconstruct sequence stratigraphic architecture, and understand the controlling processes and factors at the steep margin of a rift basin. In the first part of this work, an Eocene stratigraphic sequence is divided into three systems tracts, corresponding to different stages of lake evolution, as early expansion (EEST), late expansion-early contraction (LEECST), and late contraction (LCST). EEST is the thickest and diagnostic by the best-developed marginal and basinal …
Structural Analysis Of A Triangle Zone Culmination, Comb Rock, Lewis And Clark County, Montana, Shane S. Fussell
Structural Analysis Of A Triangle Zone Culmination, Comb Rock, Lewis And Clark County, Montana, Shane S. Fussell
Graduate Student Theses, Dissertations, & Professional Papers
A triangle zone is a structure commonly found at the leading edge of a thrust belt, characterized by a triangular cross-section of thrust faults. In the Montana triangle zone, west-dipping thrust faults intersect east-dipping ones above a regional detachment fault. Most studies of triangle zones focus on the structure in a cross-sectional sense, but little work addresses variations along the trend. The Canadian Rocky Mountain triangle zone has long been a productive petroleum province, so understanding the southern extent of this zone, where it enters Montana, is of interest for economic purposes as well as geologic understanding. Previous studies have …
Lateral Heterogeneity And Architectural Analysis Of The Wall Creek Member Of The Upper Cretaceous (Turonian) Frontier Formation, John Zupanic
Graduate Student Theses, Dissertations, & Professional Papers
The Upper Turonian Wall Creek Member (WCM) of the Frontier Formation is part of a series of marine sandstones that were deposited on the western flank of the Cretaceous Western Interior Seaway (KWIS). The KWIS was a low accommodation shallow-marine foreland basin system that included many large deltaic complexes on its western margin. Deposition of WCM deltaic deposits was strongly influenced by fourthorder glacioeustatic cycles, oceanographic circulation patterns, and tectonics related to the active Sevier fold and thrust belt to the west. An in-depth field study of the WCM was performed on the western flank of the Powder River Basin …
Hydrogeochemical Controls On Reactive And Nonreactive Solute Transport In Heterogenous Porous Media, Mahta Gholizadeh Ansari
Hydrogeochemical Controls On Reactive And Nonreactive Solute Transport In Heterogenous Porous Media, Mahta Gholizadeh Ansari
Masters Theses
"This work examines how physical and chemical heterogeneity can affect reactive and non-reactive transport in porous media. The effect of heterogeneity of the porous media is investigated both on dissolution rate of magnesite and attenuation time of nonreactive contaminants in non-reactive media. Various spatial distribution were created using statistical parameters in PETREL.A total of 6793 transport modeling simulations were run using CrunchFlow. Lasso regression was used to select most significant features and those features are then used in linear regression and deep learning models.
The magnesite dissolution simulations were performed under different permeability ratios (magnesite /sand permeability) and inlet pH. …
Near-Surface And High Resolution Seismic Imaging Of The Bennett Thrust Fault In The Indio Mountains Of West Texas, Alan Thomas Vennemann
Near-Surface And High Resolution Seismic Imaging Of The Bennett Thrust Fault In The Indio Mountains Of West Texas, Alan Thomas Vennemann
Open Access Theses & Dissertations
My research investigates the structure of the Indio Mountains in southwest Texas, 34 kilometers southwest of Van Horn, at the UTEP (University of Texas at El Paso) Field Station using newly acquired active-source seismic data. The area is underlain by deformed Cretaceous sedimentary rocks that represent a transgressive sequence nearly 2 km in total stratigraphic thickness. The rocks were deposited in mid Cretaceous extensional basins and later contracted into fold-thrust structures during Laramide orogenesis. The stratigraphic sequence is an analog for similar areas that are ideal for pre-salt petroleum reservoirs, such as reservoirs off the coasts of Brazil and Angola …
Gypsum, Calcite, And Dolomite Caprock Fabrics And Geochemistry From The Gypsum Valley Salt Diapir, Paradox Basin, Southwestern Colorado, Kevin Lerer
Open Access Theses & Dissertations
Caprocks are found on top of or in a lateral position relative to salt diapirs. The caprocks predominantly comprise sulfate minerals such as anhydrite or gypsum, which presumably accreted during the dissolution of salt from evaporite sediments. In some cases, the sulfate minerals are replaced by carbonate minerals, referred to as "carbonate caprock". Carbonate caprocks associated with salt diapirs are important because they can act as reservoirs or conduits for hydrocarbons, and because they can be easily misidentified as carbonate lithologies belonging to the stratigraphy of the sedimentary sequences adjacent to the diapir, which can jeopardize the accurate interpretation of …
Airborne Lead In El Paso, Texas, Usa, Lisa Marie Paz
Airborne Lead In El Paso, Texas, Usa, Lisa Marie Paz
Open Access Theses & Dissertations
Despite significant strides to minimize lead in our air, water, soil, food, homes, workplaces, and consumer products, sporadic and systemic lead poisoning persists in industrial societies, e.g., the contemporary Flint (Michigan, USA) municipal water tragedy. Because lead exposure is cumulative, the sum of exposure from all sources, it is important to document and update potential community or neighborhood exposure levels from such environmental compartments as air, water, and housing. Here we present ambient airborne lead levels in El Paso, Texas, USA, parsed by particulate matter (PM) size fraction, geography, and season. Dichotomous samplers at 8 stations collected particulate matter continuously …
Experimental Biomechanics Of Trinucleid Fringe Pits (Trilobita), Kirk Pearson
Experimental Biomechanics Of Trinucleid Fringe Pits (Trilobita), Kirk Pearson
Honors Papers
The morphometric uniqueness of the trinucleid family of fossil arthropods, known as the trilobites, has led to a considerable amount of attention in paleontology literature. In particular, the distinctive hourglass-shaped pits that dot their anterior have been the subject of debate for over a century. Though anatomically well understood, their function remains unknown. Many proposals have been suggested, including its use as a sieve for filter-feeding, a strong shield for defense, and a sensory mechanism to compensate for their blindness. Despite the wide range of speculations, no study has attempted to model these hypotheses experimentally. Flume experiments and mechanical strength …
Glaciovolcanic Megapillows Of Undirhliðar, Reykjanes Peninsula, Southwestern Iceland, Rachel Heineman
Glaciovolcanic Megapillows Of Undirhliðar, Reykjanes Peninsula, Southwestern Iceland, Rachel Heineman
Honors Papers
At Undirhliðar tindar on the Reykjanes Peninsula, southwestern Iceland, megapillows are among the features formed during a series of ridge-building glaciovolcanic eruptions. Mapping of the northeastern 3 km of the ridge and petrographic and geochemical analysis of the megapillow outcrops occurring throughout this area demonstrate their role in the multi-stage construction of the ridge modeled by Pollock et al. (2014). The outcrops exhibit radial jointing, bands of vesicles and glassy rims, they occur in high relief surrounded by basalt breccia resembling pillow rubble, and are composed of plagioclase-phyric olivine basalt with plagioclase-rich groundmass. They occur in multiple pillow lava units …
Ancient And Modern Fluvial Geomorphology Of Meandering System From Upstream Area Of The Mun River, Changwat Nakhon Ratchasima, Parisa Nimnate
Ancient And Modern Fluvial Geomorphology Of Meandering System From Upstream Area Of The Mun River, Changwat Nakhon Ratchasima, Parisa Nimnate
Chulalongkorn University Theses and Dissertations (Chula ETD)
At the southwestern rim of the Khorat Plateau, the upstream part of the Mun River flows through clastic sedimentary rocks leading to a massive amount of sand was transported via the Mun River to downstream. The Mun Bon Dam was constructed in 1986, and it would be effect more or less on river system. Therefore, the aim of this thesis is to analyze the geomorphological changes before and after the Mun Bon Dam construction. Moreover, the sedimentary facies from geological and shallow geophysical surveys were characterized. The geomorphic parameters was analyzed from series of aerial-photo and satellite image which were …
Apatite Fission Track Dating Of Mesozoic Siliciclastic Rocks From Khorat Group In Phu Phan Mountain Range, Northeastern Thailand, Apivut Veeravinantanakul
Apatite Fission Track Dating Of Mesozoic Siliciclastic Rocks From Khorat Group In Phu Phan Mountain Range, Northeastern Thailand, Apivut Veeravinantanakul
Chulalongkorn University Theses and Dissertations (Chula ETD)
Field and remote-sensing investigations have been performed for mapping the Mesozoic siliciclastic rocks of the Phu Phan Ranges (PPR), northeastern Thailand. Stratigraphically, the PPR study area has been remapped and is occupied by 5 distinct successive formations, including the Phu Kradung Formation with the average thickness of 93 m, the Phra Wihan Formation with the average thickness of 64 m, the Sao Khua Formation with the average thickness of 63 m, the Phu Phan with the average thickness of 84 m, and the Khok Kruat with the average thickness of 49 m. Results on field and remote sensing analyses reveal …