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Articles 21271 - 21300 of 29947
Full-Text Articles in Geology
Analysis Of Deformation Mechanisms That Formed The Shear Zones Found In The Scituate Granite, Rhode Island, Usa, Jacob Waller
Analysis Of Deformation Mechanisms That Formed The Shear Zones Found In The Scituate Granite, Rhode Island, Usa, Jacob Waller
Williams Honors College, Honors Research Projects
The rheology of the ductile middle and lower crust affects the rate and intensity of aftershocks following major seismic events. This ductile deformation in the middle crust is commonly localized in narrow shear zones, which requires a process that causes strain weakening to operate in order to form these shear zones. In order to determine the mechanisms that cause strain localization in a common crustal rock, microstructures were analyzed in and around a shear zone found in a granite, Scituate, RI, deformed during the Alleghenian orogeny. Evolution of shear zone growth was observed through optical and scanning electron microscope (SEM) …
Development Of A Synthesis Method For O2-Releasing Compound For Microbiological Experiments, Danae Greco
Development Of A Synthesis Method For O2-Releasing Compound For Microbiological Experiments, Danae Greco
Williams Honors College, Honors Research Projects
Many celestial bodies within our solar system may have habitable environments due to the presence of liquid water. Europa, one of Jupiter’s moons, may be habitable because of its liquid ocean and other potentially biologically favorable conditions. The ocean on Europa is hypothesized to contain large amounts of oxidants and low pH due to the radiolytically processed icy ocean shell. This suspected environment on Europa is similar to the composition of acid mine drainage on Earth, which can house microbial communities in environments of extreme acidity. Similar chemical reactions in Europa’s ocean may occur to produce the appropriate reduction-oxidation gradients …
Glacial Deposits, Vol. 45, 2020, Department Of Geography, Geology, And The Environment
Glacial Deposits, Vol. 45, 2020, Department Of Geography, Geology, And The Environment
Glacial Deposits
Newsletter of the Department of Geography, Geology, and the Environment
Geology And Aquifer Sensitivity Of Quaternary Glacial Deposits Overlying A Portion Of The Mahomet Buried Bedrock Valley Aquifer System, Andrew Watson, Eric W. Peterson, Dave Malone, Lisa Tranel
Geology And Aquifer Sensitivity Of Quaternary Glacial Deposits Overlying A Portion Of The Mahomet Buried Bedrock Valley Aquifer System, Andrew Watson, Eric W. Peterson, Dave Malone, Lisa Tranel
Faculty Publications - Geography, Geology, and the Environment
To characterize the distribution of Holocene and Late Quaternary deposits and to assess the contamination potential of the Mahomet Aquifer, surficial geologic and aquifer sensitivity maps of the Gibson City East 7.5-Minute Quadrangle were created. Geologic data, extent, and thickness of the geologic materials were coupled with LiDAR topographic data and analyzed using ESRI’s ArcGIS 10.6.1. Aquifer sensitivity to contamination was calculated based on the depth to the first aquifer unit, aquifer thickness, and the lithology of the aquifer materials. The surficial geologic mapping identified five lithostratigraphic units: the Cahokia Formation, the Equality Formation, the Henry Formation, and the Yorkville …
Supra-Salt Syndepositional Folding Within The Jurassic Morrison Formation, Big Gypsum Valley, Colorado, Alondra Soltero
Supra-Salt Syndepositional Folding Within The Jurassic Morrison Formation, Big Gypsum Valley, Colorado, Alondra Soltero
Open Access Theses & Dissertations
The Paradox Basin, along the Utah and Colorado border, exposes salt diapirs that form elongate "salt walls". Most exposures of sediments that were deposited during salt movement are hundreds of meters from the contacts. However, in the southeastern part of the Gypsum Valley diapir, a set of tight folds within the Jurassic Morrison Formation are preserved along the diapir margins where they overlie salt. These are best exposed at the southeastern end of Big Gypsum Valley. Previous interpretations suggested that the Morrison Formation folding and faulting occurred during dissolution of the diapir. However, field mapping reported here reveals that the …
Comparison Of Fe(Iii) Reduction Rates By Iron-Reducing Bacteria Within Sub Muros Samples From Quadrilátero Ferrífero Iron-Ore Caves, Brazil, Summer Ellis
Williams Honors College, Honors Research Projects
Previous research investigating the speleogenesis of iron-ore caves (IOC) in the Quadrilátero Ferrífero, or “Iron Quadrangle,” of Brazil suggests that microbial iron reduction and subsequent dissolution of the surrounding Fe(III) rich rocks is responsible for cave formation. A soft intra-wall substance (sub muros) containing iron-reducing bacteria (FeRB) was discovered underneath the durable crusts of cave walls. The goal of the study was to determine if reduction rates were comparable between sub muros samples, while additionally observing how different electron donors affect microbial iron reduction. To do this, I compared Fe(III) reduction rates between sub muros samples collected from …
The Impacts Of Accessibility On Vulnerability Of Place In Comfort Castle, Jamaica, Heather Thole
The Impacts Of Accessibility On Vulnerability Of Place In Comfort Castle, Jamaica, Heather Thole
Dissertations, Master's Theses and Master's Reports
Jamaica experiences meteorological, hydrological, and geological natural hazards that can produce island-wide impacts. The island’s exposure to multiple hazard types requires effective and sustainable mitigation and disaster risk management to lessen potential impacts, especially for vulnerable populations and communities. Comfort Castle, a small rural farming community, sits in the upper Rio Grande Valley of Portland parish and experiences earthquakes, landslides, hurricanes, heavy rainfall, and floods. Steep terrain and remoteness due to geographic location affect the community’s geophysical vulnerability. Their social vulnerability results from a lack of employment, health, educational, and livelihood resources within the community. Together, geophysical, and social factors …
Rain Generated Lahars Prior To The 2018 Catastrophic Eruption Of Fuego Volcano, Guatemala, Claudia Buondonno
Rain Generated Lahars Prior To The 2018 Catastrophic Eruption Of Fuego Volcano, Guatemala, Claudia Buondonno
Dissertations, Master's Theses and Master's Reports
Fuego volcano is one of the most active and hazardous volcanoes in the world. It is located in the northern part of the Central American Volcanic Arc in Guatemala and its activity can be characterized by long term, low-level background activity, and sporadic larger explosive eruptions. Its historical observations of eruptions date back to 1531, but it has been erupting vigorously since 2002 with major activity throughout 2018, producing three main eruptions in February, June and November. Its almost persistent activity generates major ashfalls, pyroclastic flows, lava flows; when heavy rains mobilize its deposits, they can form damaging lahars. Phenomena, …
Interpretive Geologic Maps And Cross Sections For Phelps, Kearney, And Adams Counties In Nebraska, Dana Divine, Leslie M. Howard
Interpretive Geologic Maps And Cross Sections For Phelps, Kearney, And Adams Counties In Nebraska, Dana Divine, Leslie M. Howard
Conservation and Survey Division: Faculty and Staff Publications
Data from thousands of test-hole and well logs were interpreted to improve understanding and management of the High Plains aquifer in a three-county study area adjacent to the Big Bend reach of the Platte River. Five principal conclusions resulted from these interpretations: (1) the extent of Neogene Ogallala deposits beneath the study area is different than previously mapped; (2) a large paleovalley incised into Cretaceous bedrock probably cuts across Kearney and Adams counties and may be the course of the ancestral Platte River prior to formation of the Big Bend; (3) a groundwater mound created by irrigation canals artificially raises …
Acoustic Space Occupancy: Combining Ecoacoustics And Lidar To Model Biodiversity Variation And Detection Bias Across Heterogeneous Landscapes, Danielle I. Rappaport, J. Andrew Royle, Douglas C. Morton
Acoustic Space Occupancy: Combining Ecoacoustics And Lidar To Model Biodiversity Variation And Detection Bias Across Heterogeneous Landscapes, Danielle I. Rappaport, J. Andrew Royle, Douglas C. Morton
United States Geological Survey: Staff Publications
There is global interest in quantifying changing biodiversity in human-modified landscapes. Ecoacoustics may offer a promising pathway for supporting multi-taxa monitoring, but its scalability has been hampered by the sonic complexity of biodiverse ecosystems and the imperfect detectability of animal-generated sounds. The acoustic signature of a habitat, or soundscape, contains information about multiple taxa and may circumvent species identification, but robust statistical technology for characterizing community-level attributes is lacking. Here, we present the Acoustic Space Occupancy Model, a flexible hierarchical framework designed to account for detection artifacts from acoustic surveys in order to model biologically relevant variation in acoustic space …
Human-Associated Species Dominate Passerine Communities Across The United States, Helen R. Sofaer, Curtis H. Flather, Catherine S. Jarnevich, Kristin P. Davis, Liba Pejchar
Human-Associated Species Dominate Passerine Communities Across The United States, Helen R. Sofaer, Curtis H. Flather, Catherine S. Jarnevich, Kristin P. Davis, Liba Pejchar
United States Geological Survey: Staff Publications
Aim: Human development and agriculture can have transformative and homogenizing effects on natural systems, shifting the composition of ecological communities towards non-native and native species that tolerate or thrive under human-dominated conditions. These impacts cannot be fully captured by summarizing species presence, as they include dramatic changes to patterns of species abundance. However, how human land use patterns and species invasions intersect to shape patterns of abundance and dominance within ecological communities is poorly understood even in well-known taxa.
Location: Conterminous United States.
Time period: 2010–2012.
Major taxa studied: Passeriformes.
Methods: We analyse continental-scale monitoring data to study the proportional …
Ecosystem Processes, Land Cover, Climate, And Human Settlement Shape Dynamic Distributions For Golden Eagle Across The Western Us, J.D. Tack, Barry R. Noon, Zachary Bowen, Brad C. Fedy
Ecosystem Processes, Land Cover, Climate, And Human Settlement Shape Dynamic Distributions For Golden Eagle Across The Western Us, J.D. Tack, Barry R. Noon, Zachary Bowen, Brad C. Fedy
United States Geological Survey: Staff Publications
Species–environment relationships for highly mobile species outside of the breeding season are often highly dynamic in response to the collective effects of everchanging climatic conditions, food resources, and anthropogenic disturbance. Capturing dynamic space-use patterns in a model-based framework is critical as model inference often drives place-based conservation planning. We applied dynamic occupancy models to broad-scale golden eagle Aquila chrysaetos survey data collected annually from 2006 to 2012 during the late summer post-fledging period in the western US. We defined survey sites as 10 km transect segments with a 1 km buffer on either transect side (n = 3540). Derived estimates …
Human-Associated Species Dominate Passerine Communities Across The United States, Helen R. Sofaer, Curtis H. Flather, Catherine S. Jarnevich, Kristin P. Davis
Human-Associated Species Dominate Passerine Communities Across The United States, Helen R. Sofaer, Curtis H. Flather, Catherine S. Jarnevich, Kristin P. Davis
United States Geological Survey: Staff Publications
Aim: Human development and agriculture can have transformative and homogenizing effects on natural systems, shifting the composition of ecological communities towards non-native and native species that tolerate or thrive under human-dominated conditions. These impacts cannot be fully captured by summarizing species presence, as they include dramatic changes to patterns of species abundance. However, how human land use patterns and species invasions intersect to shape patterns of abundance and dominance within ecological communities is poorly understood even in well-known taxa.
Location: Conterminous United States.
Time period: 2010–2012.
Major taxa studied: Passeriformes.
Methods: We analyse continental-scale monitoring data to study the proportional …
Acoustic Space Occupancy: Combining Ecoacoustics And Lidar To Model Biodiversity Variation And Detection Bias Across Heterogeneous Landscapes, Danielle I. Rappaport, J. Andrew Royle, Douglas C. Morton
Acoustic Space Occupancy: Combining Ecoacoustics And Lidar To Model Biodiversity Variation And Detection Bias Across Heterogeneous Landscapes, Danielle I. Rappaport, J. Andrew Royle, Douglas C. Morton
United States Geological Survey: Staff Publications
There is global interest in quantifying changing biodiversity in human-modified landscapes. Ecoacoustics may offer a promising pathway for supporting multi-taxa monitoring, but its scalability has been hampered by the sonic complexity of biodiverse ecosystems and the imperfect detectability of animal-generated sounds. The acoustic signature of a habitat, or soundscape, contains information about multiple taxa and may circumvent species identification, but robust statistical technology for characterizing community-level attributes is lacking. Here, we present the Acoustic Space Occupancy Model, a flexible hierarchical framework designed to account for detection artifacts from acoustic surveys in order to model biologically relevant variation in acoustic space …
Characterization Of Pallid Sturgeon (Scaphirhynchus Albus) Spawning Habitat In The Lower Missouri River, Caroline M. Elliott, Aaron J. Delonay, Kimberly Chojnacki, Robert B. Jacobson
Characterization Of Pallid Sturgeon (Scaphirhynchus Albus) Spawning Habitat In The Lower Missouri River, Caroline M. Elliott, Aaron J. Delonay, Kimberly Chojnacki, Robert B. Jacobson
United States Geological Survey: Staff Publications
Acipenseriformes (sturgeons and paddlefish) globally have declined throughout their range due to river fragmentation, habitat loss, overfishing, and degradation of water quality. In North America, pallid sturgeon (Scaphirhynchus albus) populations have experienced poor to no recruitment, or substantial levels of hybridization with the closely related shovelnose sturgeon (S. platorynchus). The Lower Missouri River is the only portion of the species’ range where successful reproduction and recruitment of genetically pure pallid sturgeon have been documented. This paper documents spawning habitat and behavior on the Lower Missouri River, which comprises over 1,300 km of unfragmented river habitat. The …
Late Quaternary Sea-Level History Of Saipan, Commonwealth Of The Northern Mariana Islands, Usa: A Test Of Tectonic Uplift And Glacial Isostatic Adjustment Models, Daniel R. Muhs, Eugene S. Schweig, Kathleen R. Simmons
Late Quaternary Sea-Level History Of Saipan, Commonwealth Of The Northern Mariana Islands, Usa: A Test Of Tectonic Uplift And Glacial Isostatic Adjustment Models, Daniel R. Muhs, Eugene S. Schweig, Kathleen R. Simmons
United States Geological Survey: Staff Publications
In 1979, S. Uyeda and H. Kanamori proposed a tectonic model with two end members of a subduction-boundary continuum: the “Chilean” type (shallow dip of the subducting plate, great thrust events, compression, and uplift of the overriding plate) and a “Mariana” type (steep dip of the subducting plate, no great thrust events, tension, and no uplift). This concept has been used to explain variable rates of Quaternary uplift around the Pacific Rim, yet no uplift rates have been determined for the Mariana Islands themselves, one of the end members in this model. We studied the late Quaternary Tanapag Limestone, which …
Stratigraphy And Geochemistry Of Rock Salt From Maha Sarakham Formation In Changwat Chaiyaphum, Northeastern Thailand, Pranot Rattana
Stratigraphy And Geochemistry Of Rock Salt From Maha Sarakham Formation In Changwat Chaiyaphum, Northeastern Thailand, Pranot Rattana
Chulalongkorn University Theses and Dissertations (Chula ETD)
Maha Sarakham Formation is one of massive potash deposits in the Khorat Plateau extending from northeastern of Thailand to central of Lao PDR. Maha Sarakham Formation consists of three rock salt members (the lower, middle and upper members) interbedded with claystone. Potash minerals are associated with the thick bed of rock salt in the upper part of lower salt member. Previous studies are still under discussion on whether the origin of rock salt from marine or non-marine (hydrothermal origin and mixed fluids) deposit. The purpose of this study is to analyze the origin of rock salt based on elemental compositions …
Fusulinacean Biostratigraphy And Carbonate Petrography Of Khao Khwang And Khao Khad Formations, Saraburi Province, Sutharat Sirot
Fusulinacean Biostratigraphy And Carbonate Petrography Of Khao Khwang And Khao Khad Formations, Saraburi Province, Sutharat Sirot
Chulalongkorn University Theses and Dissertations (Chula ETD)
These research purposes are to study petrography, fusulinids assemblage and age and study biostratigraphy correlation of Khao Khwang and Khao Khad Formations, Saraburi province. The fusulinids from the study area belong to 5 families, 11 subfamilies, 15 genera and 15 species including Robustoschwagerina, Yangchienia, Parafusulina loeyensis, Parafusulina gigantea, Laosella edoensis, Pseudofusulina, Chusenella chihsiaensis, Chusenella (Chusenella) shengi, Verbeekina verbeeki, Misellina, Pseudodoliolina, Thailandina buravasi, Neoschwagerina megasphaerica, Colania douvillei, Lepidolina shiraiwensis, Presumatrina ciryi, Sumatrina annae and Sumatrina cf. longissima. These fusulinids indicated that Khao Khad Formation was deposited oldest in Sakmarian to Yakhtashian and youngest in Midian age and Khao Khwang Formation was …
Petrochemistry Of Intrusive Rocks In Tha Takiap District, Chachoengsao Province, Thanaz Watcharamai
Petrochemistry Of Intrusive Rocks In Tha Takiap District, Chachoengsao Province, Thanaz Watcharamai
Chulalongkorn University Theses and Dissertations (Chula ETD)
In Thailand, alkaline granitoid rocks are less widespread and crop out in less extend as small stocks or plutons. The study areas are located in 2 vicinities of Tha Takiap and Mae Yan areas which respectively are a part of the eastern and central granite belts. Petrographic study of the rocks from both areas show that alkaline feldspar is the principal mineral phase with small amount of quartz and plagioclase. Compositionally, the investigated rocks fall in the range of alkali feldspar syenite to quartz-alkali feldspar syenite. High concentration of Na2O+K2O and high ratio of FeOtot/(FeOtot+MgO) vs SiO2 indicate that most …
Tropical Cyclone Hazards In Relation To Propagation Speed, Jiehao Huang
Tropical Cyclone Hazards In Relation To Propagation Speed, Jiehao Huang
Dissertations and Theses
As the population and infrastructure along the US East Coast increase, it becomes increasingly important to study the characteristics of tropical cyclones that can impact the coast. A recent study shows that the propagation speed of tropical cyclones has slowed over the past 60 years, which can lead to greater accumulation of precipitation and greater storm surge impacts. The study presented herein is meant to examine and analyze the relationships that exist between the propagation speed of tropical cyclones, their surface wind strength, displacement angles, and cyclone averaged winds. This analysis is focused on tropical cyclones spanning from 1950-2015 in …
Structure, Evolution, And Mesoscopic Deformation Patterns Near The Tourmaline Hill Salt Sheet, Umberatana Station, South Australia, Lillian Ruth Lueck
Structure, Evolution, And Mesoscopic Deformation Patterns Near The Tourmaline Hill Salt Sheet, Umberatana Station, South Australia, Lillian Ruth Lueck
Graduate Research Theses & Dissertations
Halokinetic structures have been proven to serve as both structural and stratigraphic traps for petroleum and mineralizing ore fluids, making them critical to the energy and technology needs of society. Although modern exploration for these resources uses often uses 3-D seismic imagery, these data often cannot resolve the complexity of the strata within 300 meters of the salt sediment interface, an area that is critical to the trapping or migration of fluids. Because of this lack of constraint, drilling near salt risks encountering unexpected overturned strata, repeated units, overpressure, or abrupt changes in stress state, making it imperative to understand …
Body Wave Analysis For Low-Angle Thrust Quakes On Titan: Implications For Dragonfly, John William Owens
Body Wave Analysis For Low-Angle Thrust Quakes On Titan: Implications For Dragonfly, John William Owens
Graduate Research Theses & Dissertations
Little is known of the structure and seismic nature of planetary bodies that have an outer shell of ice instead of a rocky crust. These bodies are called icy satellites and one such body, Saturn’s moon Titan, is unique because of its thick atmosphere, methane cycle, and assumed salty subsurface ocean. NASA’s Dragonfly mission, set to launch in 2026, will use a robotic rotorcraft to transport various instruments, including a seismometer, to the Shangri-La dune field on Titan. Until then, Titan’s seismic regime can be estimated by simulating wave propagation through assumed subsurface layers using source models. Ridge belts with …
The Effect Of Spacing Of Vetiver Grass (Chrysopogon Zizanioides) Hedgerows On Hillslope Erosion In Eastern Region, Ghana, Evan R. Lanese
The Effect Of Spacing Of Vetiver Grass (Chrysopogon Zizanioides) Hedgerows On Hillslope Erosion In Eastern Region, Ghana, Evan R. Lanese
Dissertations, Master's Theses and Master's Reports
Soil erosion in Ghana negatively effects many small holder farmers due to heavy rainfall, continuous land use, and a changing climate. Inexpensive, local, and sustainable practices that can be used to reduce soil movement thus building productive soils would benefit farmers in Ghana. Vetiver grass (Chrysopogon zizanioides) has been used to this effect worldwide. Its local availability and positive reputation leaves desire to learn about its applicability in Ghana. A field study was conducted on plots of sloping farmland (10ft by 60ft) with three treatments: (1) control with no vetiver grass, (2) two vetiver grass hedgerows, (3) four …
Model-Based Estimates Of The Timing Of Brine Flux Into The Victoria Land Basin From The Mcmurdo Dry Valleys, Antarctica, Valerie Nicole Voisin
Model-Based Estimates Of The Timing Of Brine Flux Into The Victoria Land Basin From The Mcmurdo Dry Valleys, Antarctica, Valerie Nicole Voisin
Graduate Research Theses & Dissertations
Submarine groundwater discharge (SGD) at a continental scale is one of the least constrained components of the hydrologic cycle and may represent a significant flux of iron and silica waters to the global ocean. Quantifying SGD along the Antarctic margin is complicated by complex subglacial and subsurface hydrogeology and limited observational data. Airborne transient electromagnetic (AEM) surveys have identified extensive high-salinity subsurface brines in the McMurdo Dry Valleys (MDV) that are hydrologically connected to surface features in the MDV (e.g. Taylor Glacier, saline lakes) and are potentially a significant source of SGD to McMurdo Sound. A 2D numerical model was …
Copper And Gold In Vapors And Liquids As A Function Of Hcl At 700°C And 100 Mpa, Corrie A. Lucchesi
Copper And Gold In Vapors And Liquids As A Function Of Hcl At 700°C And 100 Mpa, Corrie A. Lucchesi
Graduate Research Theses & Dissertations
Porphyry ore deposits are major sources of copper (Cu) and gold (Au) and form when a magmatic volatile phase (MVP) exsolves from a porphyritic intermediate to felsic melt and transports metals to surrounding country rock where they precipitate in an ore zone. There is a consensus that the chloride concentration of the MVP has a direct relationship to the concentration of Cu and Au in the MVP, but the role of dissolved HCl on Cu and Au concentrations has not been addressed. It is hypothesized that increasing HCl concentrations in the MVP will result in higher concentrations of Cu and …
Estimating Paleotemperatures In The Amundsen Sea For The Last 620,000 Years Through Diatom Morphometrics (Iodp Expedition 379), Joseph Robert Mastro
Estimating Paleotemperatures In The Amundsen Sea For The Last 620,000 Years Through Diatom Morphometrics (Iodp Expedition 379), Joseph Robert Mastro
Graduate Research Theses & Dissertations
As global climate continues to rapidly change over the coming decades, West Antarctica will continue to be a significant area of concern due to its susceptibility to marine ice sheet collapse. Past collapses during Pleistocene interglacials have been hypothesized but uncertainty exists with respect to the precise timing of specific collapse events. Drill core samples collected from the Amundsen Sea continental rise during IODP Expedition 379 allow for analysis of a more continuous record of Pleistocene glacial-interglacial cycles. Here we report paleotemperature estimates from the Amundsen Sea spanning the last 620 kyr with the objective of identifying likely late Pleistocene …
Paleohydrology And Machine-Assisted Estimation Of Paleogeomorphology Of Fluvial Channels Of The Lower Middle Pennsylvanian Allegheny Formation, Birch River, Wv, Oluwasegun O. Abatan, Amy Weislogel
Paleohydrology And Machine-Assisted Estimation Of Paleogeomorphology Of Fluvial Channels Of The Lower Middle Pennsylvanian Allegheny Formation, Birch River, Wv, Oluwasegun O. Abatan, Amy Weislogel
Faculty & Staff Scholarship
Rivers transport sediments in a source to sink system while responding to allogenic controls of the depositional system. Stacked fluvial sandstones of the Middle Pennsylvanian (Desmoinesian Stage, ∼310–306 Ma) Allegheny Formation (MPAF) exposed at Birch River, West Virginia exhibit change in sedimentary structure and depositional style, reflecting changes in allogenic behavior. Paleohydrologic and numerical analysis were used to quantify geomorphological and paleohydrologic variations reflected by MPAF fluvial deposits with the goal of understanding the controls on resulting fluvial sandstone architecture in these different systems. Channel body geometry, sedimentary structures, and sandstone grain size distribution were used to reconstruct the paleoslope …
The Transition From Planar To En Echelon Morphology In A Single Vein In Shale: Insights From X-Ray Computed Tomography Scanning, Graham Dm Andrews, Sarah R. Brown, Johnathan Moore, Dustin Crandall, Paige Mackey
The Transition From Planar To En Echelon Morphology In A Single Vein In Shale: Insights From X-Ray Computed Tomography Scanning, Graham Dm Andrews, Sarah R. Brown, Johnathan Moore, Dustin Crandall, Paige Mackey
Faculty & Staff Scholarship
En echelon fractures and veins are among the most common and distinctive geological structures, yet their three-dimensional forms and relationships to surrounding structures are commonly unclear. X-ray computed tomography (CT) offers an unrivaled ability to examine structures within rocks in three dimensions, and it is applied here to a sample of drill core from the Marcellus Shale of southwestern Pennsylvania (USA). CT images yield qualitative and quantitative data on the transition from a pyrite-rich planar vein to an en echelon veinlet array, and on the heterogeneity of veinlets within the array. Using a combination of three- and two-dimensional images, geometric …
History Of Natural And Anthropogenic Activities In Lake Izabal, Eastern Guatemala: Using Geochemical Evidence To Record Recent Contamination, Elisandra Hernandez
History Of Natural And Anthropogenic Activities In Lake Izabal, Eastern Guatemala: Using Geochemical Evidence To Record Recent Contamination, Elisandra Hernandez
Doctoral Dissertations
”Water is essential for human subsistence. Stable freshwater supplies are needed as a source of food, drinking water, for transportation, recreation and economic development. Despite their recognized importance, anthropogenic activities have altered freshwater ecosystems around the world. Lake Izabal is the habitat for diverse aquatic species of flora and fauna, some of which are endemic and endangered. Its importance notwithstanding, anthropogenic activities developed in Lake Izabal’s catchment in recent years have compromised its status. This study used paleolimnological techniques to link past and recent anthropogenic activities such as mining operations and recent tilapia aquaculture. Relative abundances and concentrations of Pb, …
Predictive Geohazard Mapping Using Lidar And Satellite Imagery In Missouri And Oklahoma, Usa, Olufeyisayo B. Ososami
Predictive Geohazard Mapping Using Lidar And Satellite Imagery In Missouri And Oklahoma, Usa, Olufeyisayo B. Ososami
Doctoral Dissertations
”Light Detection and Ranging (LiDAR) and satellite imagery have become the most utilized remote sensing technologies for compiling inventories of surficial geologic conditions. Point cloud data obtained from multi-spectral remote sensing methods provide a detailed characterization of the surface features, in particular, the detailed surface manifestations of underlying geologic structures. When combined, point clouds eliminate bias from visual inconsistencies and/or statistical values. This research explores the competence of point clouds derived from LiDAR and Unmanned Aerial Systems (UAS) as a predictive tool in evaluating various geohazards. It combines these data sets with other remote sensing techniques to evaluate the sensitivity …