Open Access. Powered by Scholars. Published by Universities.®

Geology Commons

Open Access. Powered by Scholars. Published by Universities.®

5251 Full-Text Articles 6863 Authors 863068 Downloads 129 Institutions

All Articles in Geology

Faceted Search

5251 full-text articles. Page 1 of 121.

Toxicity Of Fluorescent Tracers And Their Degradation Byproducts, Philippe Gombert, Hugues Biaudet, René de Sèze, Pascal Pandard, Jean Carré 2017 INERIS

Toxicity Of Fluorescent Tracers And Their Degradation Byproducts, Philippe Gombert, Hugues Biaudet, René De Sèze, Pascal Pandard, Jean Carré

International Journal of Speleology

Tracer tests are frequently used to delineate catchment area of water supply springs in karstic zones. In the karstic chalk of Normandy, the main tracers used are fluorescent: uranine, sulforhodamine B, naphtionate, and Tinopal®. In this area, a statistical analysis shows that less than half of the injected tracers joins the monitored restitution points and enters the drinking water system where they undergo chlorination. Most of the injected tracers is absorbed in the rock matrix or is thrown out of the aquifer via karstic springs: then it can join superficial waters where it is degraded due to the sun and ...


Climate Change Adaptation For Southern California Groundwater Managers: A Case Study Of The Six Basins Aquifer, Frank Lyles 2017 Pomona College

Climate Change Adaptation For Southern California Groundwater Managers: A Case Study Of The Six Basins Aquifer, Frank Lyles

Pomona Senior Theses

Groundwater has been very important to the economic development of Southern California, and will continue to be a crucial resource in the 21st century. However, Climate Change threatens to disrupt many of the physical and economic processes that control the flow of water in and out of aquifers. One groundwater manager, the Six Basins Watermaster in eastern Los Angeles and western San Bernardino Counties, has developed a long-term planning document called the Strategic Plan that mostly fails to address the implications of Climate Change, especially for local water supplies. This thesis presents an in-depth analysis of the Six Basin Watermaster ...


Geologic And Geochemical Characterization Of Cross-Communication Potential Within The Northern Edwards Aquifer System, Texas, Ingrid J. Eckhoff 2016 Stephen F. Austin State University

Geologic And Geochemical Characterization Of Cross-Communication Potential Within The Northern Edwards Aquifer System, Texas, Ingrid J. Eckhoff

Electronic Theses and Dissertations

The Edwards Aquifer is a large, complex groundwater system located throughout Central Texas in association with the Balcones Fault Zone. The San Antonio and Barton Spring segments of the Edwards Aquifer have been extensively studied in the past because they provide groundwater resources to the largely urbanized areas of San Antonio and Austin, respectively, and smaller communities along the Interstate 35 corridor. Previous research has been conducted on these southern and central portions of the Edwards Aquifer system, which have characterized the structural, hydrogeological and geochemical variations within the highly karsted region. However, the Northern Segment of the Edwards Aquifer ...


An Investigation Into The Origin, Composition, And Commercial Significance Of A Sedimentary Subsalt Formation: Keathley Canyon, Gulf Of Mexico, David Aaron Brassieur 2016 University of New Orleans, New Orleans

An Investigation Into The Origin, Composition, And Commercial Significance Of A Sedimentary Subsalt Formation: Keathley Canyon, Gulf Of Mexico, David Aaron Brassieur

University of New Orleans Theses and Dissertations

Sub-salt oil and gas formations in deep-water northern Gulf of Mexico are high priority targets. Advances in seismic processing allow for high-resolution, below-salt imaging. Understanding the modes of salt emplacement provide insight into sub-salt traps and potential drilling hazards.

A sub-salt sedimentary unit lies in the Keathley Canyon protraction. Autosutures created the transport-parallel lineaments of the upper surface of the unit. In addition, highly variable sediment aggradation rates created ramps, flats, and basal cutoffs along the base of the allochthon as salt and sediment competed for space. Seismic models identify modes of salt emplacement, salt/sediment interactions, and mechanisms responsible ...


Petrography, Stable Isotope Compositions, Microraman Spectroscopy, And Presolar Components Of Roberts Massif 04133: A Reduced Cv3 Carbonaceous Chrondrite, Jemma Davidson, Devin L. Schrader, Conel M. Alexander, Dante S. Lauretta, Henner Busemann, Ian A. Franchi, Richard C. Greenwood, Harold Connolly Jr., Kenneth J. Domanik, Alexander Verchovsky 2016 Selected Works

Petrography, Stable Isotope Compositions, Microraman Spectroscopy, And Presolar Components Of Roberts Massif 04133: A Reduced Cv3 Carbonaceous Chrondrite, Jemma Davidson, Devin L. Schrader, Conel M. Alexander, Dante S. Lauretta, Henner Busemann, Ian A. Franchi, Richard C. Greenwood, Harold Connolly Jr., Kenneth J. Domanik, Alexander Verchovsky

Harold Connolly

Here, we report the mineralogy, petrography, C-N-O-stable isotope compositions, degree of disorder of organic matter, and abundances of presolar components of the chondrite Roberts Massif (RBT) 04133 using a coordinated, multitechnique approach. The results of this study are inconsistent with its initial classification as a Renazzo-like carbonaceous chondrite, and strongly support RBT 04133 being a brecciated, reduced petrologic type >3.3 Vigarano-like carbonaceous (CV) chondrite. RBT 04133 shows no evidence for aqueous alteration. However, it is mildly thermally altered (up to approximately 440 °C); which is apparent in its whole-rock C and N isotopic compositions, the degree of disorder of ...


Towards Understanding The Dynamical Evolution Of Asteroid 25143 Itokawa: Constraints From Sample Analysis, Harold C. Connolly Jr., Dante S. Lauretta, Kevin J. Walsh, Shogo Tachibana, William F. Bottke Jr. 2016 Rowan University

Towards Understanding The Dynamical Evolution Of Asteroid 25143 Itokawa: Constraints From Sample Analysis, Harold C. Connolly Jr., Dante S. Lauretta, Kevin J. Walsh, Shogo Tachibana, William F. Bottke Jr.

Harold Connolly

The data from the analysis of samples returned by Hayabusa from asteroid 25143 Itokawa are used to constrain the preaccretion history, the geological activity that occurred after accretion, and the dynamical history of the asteroid from the main belt to near-Earth space. We synthesize existing data to pose hypotheses to be tested by dynamical modeling and the analyses of future samples returned by Hayabusa 2 and OSIRIS-REx. Specifically, we argue that the Yarkosky-O’Keefe-Radzievskii-Paddack (YORP) effect may be responsible for producing geologically high-energy environments on Itokawa and other asteroids that process regolith and essentially affect regolith gardening.


Modern Fair-Weather And Storm Sediment Transport Around Ship Island, Mississippi: Implications For Coastal Habitats And Restoration Efforts, Eve Rettew Eisemann 2016 University of Southern Mississippi

Modern Fair-Weather And Storm Sediment Transport Around Ship Island, Mississippi: Implications For Coastal Habitats And Restoration Efforts, Eve Rettew Eisemann

Master's Theses

The Mississippi – Alabama barrier island chain is experiencing accelerated sea level rise, decreased sediment supply, and frequent hurricane impacts. These three factors drive unprecedented rates of morphology change and ecosystem reduction. All islands in the chain have experienced land loss on the order of hectares per year since records began in the 1840s. In 1969, Hurricane Camille impacted as a Category 5, breaching Ship Island, and significantly reduced viable seagrass habitat. Hurricane Katrina impacted as a Category 3 in 2005, further widening Camille Cut. To better understand the sustainability of these important islands and the ecosystems they support, sediment transport ...


Characterization And Delineation Of Karst Geohazards Along Rm652 Using Electrical Resistivity Tomography, Culberson County, Texas, Adam F. Majzoub 2016 Stephen F Austin State University

Characterization And Delineation Of Karst Geohazards Along Rm652 Using Electrical Resistivity Tomography, Culberson County, Texas, Adam F. Majzoub

Electronic Theses and Dissertations

The Delaware Basin of West Texas and southeastern New Mexico is the major western subdivision of the Permian Basin and a northern extension of the Chihuahuan Desert. The major evaporite unit within the Delaware Basin is the Castile Formation, which consists of gypsum/anhydrite and is highly susceptible to dissolution and karsting. Manifestations of karst within the Castile outcrop are abundant and include sinkholes, subsidence features and caves, both epigene and hypogene in origin.

Land reconnaissance surveys conducted during the summer of 2015 documented abundant karst landforms in close proximity to a major thoroughfare, RM 652, in Culberson County, Texas ...


Geotechnical Properties Of The Travis Peak (Hosston) Formation In East Texas: A Compressive And Tensile Strength Analysis Using Regression Analysis., Pawan Kakarla 2016 Stephen F Austin State University

Geotechnical Properties Of The Travis Peak (Hosston) Formation In East Texas: A Compressive And Tensile Strength Analysis Using Regression Analysis., Pawan Kakarla

Electronic Theses and Dissertations

The estimation of rock mass strength is a key parameter in geotechnical engineering which is used in the design of geotechnical structures like tunnels, dams and slopes. Geotechnical engineering is the branch of civil engineering which works on the principles of soil and rock mechanics to evaluate subsurface conditions, stability of slopes, foundations of structures and construction of earthworks. The main focus of this study was to calculate the strength of Lower Cretaceous Travis Peak Formation rocks of East Texas and to check the accuracy by comparing it with Regression analysis. The parameters which were used were the Uniaxial Compression ...


Speleogenesis And Delineation Of Megaporosity And Karst Geohazards Through Geologic Cave Mapping And Lidar Analyses Associated With Infrastructure In Culberson County, Texas, Jon T. Ehrhart 2016 Stephen F. Austin State University

Speleogenesis And Delineation Of Megaporosity And Karst Geohazards Through Geologic Cave Mapping And Lidar Analyses Associated With Infrastructure In Culberson County, Texas, Jon T. Ehrhart

Electronic Theses and Dissertations

The Gypsum Plain region of the Delaware Basin hosts approximately 1800 km2 of the Castile Formation outcrop. A myriad of karstic developments from closed sinkholes to large multi-kilometer cave systems have been documented within the region. Karst studies on the distribution and speleogenetic evolution within Castile strata began within the last decade with ever increasing data resolution. In this study, a combination of both physical field surveys and analyses of high resolution (~30 cm accuracy) LiDAR data was used to create a theoretical model for karst development across the region. This idealized model considers speleogenetic formation type variations (hypogene ...


Microstructural Analysis Of Thermoelastic Response, Nonlinear Creep, And Pervasive Cracking In Heterogeneous Materials, Alden C. Cook 2016 University of Maine

Microstructural Analysis Of Thermoelastic Response, Nonlinear Creep, And Pervasive Cracking In Heterogeneous Materials, Alden C. Cook

Electronic Theses and Dissertations

This dissertation is concerned with the development of robust numerical solution procedures for the generalized micromechanical analysis of linear and nonlinear constitutive behavior in heterogeneous materials. Although the methods developed are applicable in many engineering, geological, and materials science fields, three main areas are explored in this work. First, a numerical methodology is presented for the thermomechanical analysis of heterogeneous materials with a special focus on real polycrystalline microstructures obtained using electron backscatter diffraction techniques. Asymptotic expansion homogenization and finite element analysis are employed for micromechanical analysis of polycrystalline materials. Effective thermoelastic properties of polycrystalline materials are determined and compared ...


Storm Induced Beach Profile Changes Along The Coast Of Treasure Island, West-Central Florida, U.S.A., Zhaoxu Zhu 2016 University of South Florida

Storm Induced Beach Profile Changes Along The Coast Of Treasure Island, West-Central Florida, U.S.A., Zhaoxu Zhu

Graduate Theses and Dissertations

Storms play a significant role in beach morphodynamics. Storm-induced beach-profile changes and their longshore variations are investigated in this study. The impacts of four summer tropical storms and two series of winter storms over the last 10 years along the coast of Treasure Island were documented. Tropical storms Alberto in 2006, Fay in 2008, Debby in 2012, Hermine in 2016 and winter storms in winter seasons of 2014 and 2015 are discussed in this study. In general, the Treasure Island beach experienced more erosion generated by tropical storms with greater intensity, but shorter duration, as compared to winter storms due ...


A Gis Analysis Of Waulsortian-Like Mounds In The Mississippian Of Kentucky And Tennessee, Philip Roberson 2016 Murray State University

A Gis Analysis Of Waulsortian-Like Mounds In The Mississippian Of Kentucky And Tennessee, Philip Roberson

Scholars Week

Following a mass extinction nearly 365 million years ago, bryozoans and crinoids replaced corals and stromatoporoids as the dominant framework organisms in reefs and, during the very earliest part of the Carboniferous period, they built reef-like structures that are known from Europe, North America and Africa. They are characterized by large size, a matrix of carbonate mud, and their major framework organisms.

Waulsortian-like mounds occur in geographically isolated patches in outcrop and in the subsurface of central Tennessee and Kentucky where they are associated with hydrocarbon production. These mounds have the same characteristic organisms as the European mounds and do ...


Tracking Earthquake Frequency And Intensity In Oklahoma, Kristin Lorenzini 2016 Murray State University

Tracking Earthquake Frequency And Intensity In Oklahoma, Kristin Lorenzini

Scholars Week

The purpose of this project is to show the dramatic increase of earthquakes that have occurred in Oklahoma over the past eight years that have been correlated to fracking in the area. Starting in 2009, before fracking took place in Oklahoma, there were a total of 33 earthquakes throughout the whole year. In 2010, when fracking began in Oklahoma, the number of earthquakes spiked to over 100 in one year. The number of earthquakes grew over the years and in 2015 there were over 2,000. Data from 2016 were also used but only through the month of September, the ...


Landform Mapping Of The Clarks River Alluvial System Using Lidar Dems, Benedict W. Ferguson 2016 Murray State University

Landform Mapping Of The Clarks River Alluvial System Using Lidar Dems, Benedict W. Ferguson

Scholars Week

The Clarks River is located in western Kentucky near the city of Benton. It travels through and weathers lacustrine or lake deposits as well as fluvial or river deposits. These deposits are also overlain by loess deposited from the last glacial maximum. Historically, people have taken advantage of these rich deposits for agriculture which has led to increased settlement. With increased settlement, the river has experienced alteration. The west fork of the Clarks River has been channelized while the east fork of the Clarks River has managed to remain un-channelized and has since been allowed to run relatively freely.

Detailed ...


Change Detection Of Mount Nyiragongo Post Eruption, Molly E. Karnes 2016 Murray State University

Change Detection Of Mount Nyiragongo Post Eruption, Molly E. Karnes

Scholars Week

Because of the dangerous nature of volcanic eruptions, it makes them very difficult to study, however this makes them even more important for us to study because of how much destruction they can cause in such a short amount of time. We need to study all parts of an eruption to gain more insight into the specifics of how a volcano works. Having a better understanding of how large of an area is effected by an eruption will allow governments to decide on evacuation procedures. The goal of my project is to answer a very simple question, “How can we ...


Unblocking Temperatures Of Viscous Remanent Magnetism In Displaced Granitic Boulders, Icicle Creek Glacial Moraines (Washington, Usa), Juliet G. Crider, Danika M. Globokar, Russ F. Burmester, Bernard A. Housen 2016 Western Washington University

Unblocking Temperatures Of Viscous Remanent Magnetism In Displaced Granitic Boulders, Icicle Creek Glacial Moraines (Washington, Usa), Juliet G. Crider, Danika M. Globokar, Russ F. Burmester, Bernard A. Housen

Bernard A. Housen

Viscous remanent magnetization (VRM) may partially overprint original magnetization in rocks displaced by geomorphic events. An established theoretical relationship between the time and temperature of acquisition of VRM and the time and temperature of demagnetization suggests that laboratory demagnetization (unblocking) of VRM can be used to estimate the displacement age of rocks. We test this hypothesis at four nested glacial moraines in the Icicle Creek drainage of central Washington, the ages of which were previously determined by cosmogenic surface exposure dating. The moraines are composed primarily of granodiorite boulders, and magnetic remanence is carried dominantly by magnetite. Both the maximum ...


Rock Magnetism Of Hematitic "Bombs" From The Araguainha Impact Structure, Brazil, Luigi Jovane, Elder Yokoyama, Takele Seda, Russell F. Burmester, Ricardo I.F. Trindade, Bernard A. Housen 2016 Western Washington University

Rock Magnetism Of Hematitic "Bombs" From The Araguainha Impact Structure, Brazil, Luigi Jovane, Elder Yokoyama, Takele Seda, Russell F. Burmester, Ricardo I.F. Trindade, Bernard A. Housen

Russ R. Burmester

Hematite impact “bombs” are one of the most striking (and enigmatic) features of the large Araguainha impact structure in central Brazil. They have both porous or massive textures, elongated shapes from 5 to 50 cm in diameter, and botryoidal textures that suggest hydrothermal origin. Some authors have considered these objects as a possible analog of hematite nodules found in Mars, and consequently related to a hydrothermal system. Here we report rock magnetic measurements, X-ray diffraction and Mössbauer spectra for both massive and porous samples for a detailed description of the hematite. Room temperature magnetic measurements, including hysteresis loops, back-field and ...


Unblocking Temperatures Of Viscous Remanent Magnetism In Displaced Granitic Boulders, Icicle Creek Glacial Moraines (Washington, Usa), Juliet G. Crider, Danika M. Globokar, Russ F. Burmester, Bernard A. Housen 2016 Western Washington University

Unblocking Temperatures Of Viscous Remanent Magnetism In Displaced Granitic Boulders, Icicle Creek Glacial Moraines (Washington, Usa), Juliet G. Crider, Danika M. Globokar, Russ F. Burmester, Bernard A. Housen

Russ R. Burmester

Viscous remanent magnetization (VRM) may partially overprint original magnetization in rocks displaced by geomorphic events. An established theoretical relationship between the time and temperature of acquisition of VRM and the time and temperature of demagnetization suggests that laboratory demagnetization (unblocking) of VRM can be used to estimate the displacement age of rocks. We test this hypothesis at four nested glacial moraines in the Icicle Creek drainage of central Washington, the ages of which were previously determined by cosmogenic surface exposure dating. The moraines are composed primarily of granodiorite boulders, and magnetic remanence is carried dominantly by magnetite. Both the maximum ...


Hydrogeochemical Evaluation Of The Uinta Formation And Green River Formation, Piceance Creek Basin, Northwestern Colorado, Usa, Megan E. Masterson 2016 Portland State University

Hydrogeochemical Evaluation Of The Uinta Formation And Green River Formation, Piceance Creek Basin, Northwestern Colorado, Usa, Megan E. Masterson

Dissertations and Theses

The Piceance Creek Basin in northwestern Colorado contains extensive oil shale deposits that produce natural gas and which could potentially yield ~1.5 trillion barrels of shale oil. However, much of the oil shale lies at depths too great for traditional mining practices and various innovative approaches for in situ conversion of kerogen to oil have been proposed. A firm understanding of the existing hydrogeochemistry is needed as resulting mineralogical changes or rock-fluid reactions may affect rock porosity and permeability. Using an existing database complied by the USGS, the water chemistry of 267 surface and groundwater samples in the Piceance ...


Digital Commons powered by bepress