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2022

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Articles 3121 - 3150 of 5201

Full-Text Articles in Geology

Mgrre_Thinsections_05_A_1, Mgrre Aug 2022

Mgrre_Thinsections_05_A_1, Mgrre

Thin Sections

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Compositionally And Density Stratified Igneous Terrain In Jezero Crater, Mars, Roger C. Wiens, Arya Udry, Olivier Beyssac, Cathy Quantin-Nataf, Nicolas Mangold, 80+ Authors Contributed To This Work Aug 2022

Compositionally And Density Stratified Igneous Terrain In Jezero Crater, Mars, Roger C. Wiens, Arya Udry, Olivier Beyssac, Cathy Quantin-Nataf, Nicolas Mangold, 80+ Authors Contributed To This Work

Geoscience Faculty Research

Before Perseverance, Jezero crater’s floor was variably hypothesized to have a lacustrine, lava, volcanic airfall, or aeolian origin. SuperCam observations in the first 286 Mars days on Mars revealed a volcanic and intrusive terrain with compositional and density stratification. The dominant lithology along the traverse is basaltic, with plagioclase enrichment in stratigraphically higher locations. Stratigraphically lower, layered rocks are richer in normative pyroxene. The lowest observed unit has the highest inferred density and is olivine-rich with coarse (1.5 millimeters) euhedral, relatively unweathered grains, suggesting a cumulate origin. This is the first martian cumulate and shows similarities to martian meteorites, which …

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Seasonality Of Precipitation In The Southwestern United States During The Late Pleistocene Inferred From Stable Isotopes In Herbivore Tooth Enamel, Matthew J. Kohn, Kathleen B. Springer, Jeffrey S. Pigati, Linda M. Reynard, Amanda E. Drewicz, Justin Crevier, Eric Scott Aug 2022

Seasonality Of Precipitation In The Southwestern United States During The Late Pleistocene Inferred From Stable Isotopes In Herbivore Tooth Enamel, Matthew J. Kohn, Kathleen B. Springer, Jeffrey S. Pigati, Linda M. Reynard, Amanda E. Drewicz, Justin Crevier, Eric Scott

United States Geological Survey: Staff Publications

The late Pleistocene was a climatically dynamic period, with abrupt shifts between cool-wet and warmdry conditions. Increased effective precipitation supported large pluvial lakes and long-lived spring ecosystems in valleys and basins throughout the western and southwestern U.S., but the source and seasonality of the increased precipitation are debated. Increases in the proportions of C4/(C4+ C3) grasses in the diets of large grazers have been ascribed both to increases in summer precipitation and lower atmospheric CO2 levels. Here we present stable carbon and oxygen isotope data from tooth enamel of late Pleistocene herbivores recovered …

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The Art Of Landslides: How Stochastic Mass Wasting Shapes Topography And Influences Landscape Dynamics, Benjamin Campforts, Charles Shobe, Irina Overeem, Gregory Tucker Aug 2022

The Art Of Landslides: How Stochastic Mass Wasting Shapes Topography And Influences Landscape Dynamics, Benjamin Campforts, Charles Shobe, Irina Overeem, Gregory Tucker

Faculty & Staff Scholarship

Bedrock landslides shape topography and mobilize large volumes of sediment. Yet, interactions between landslide-produced sediment and fluvial systems that together govern large-scale landscape evolution are not well understood. To explain morphological patterns observed in steep, landslide-prone terrain, we explicitly model stochastic landsliding and associated sediment dynamics. The model accounts for several common landscape features such as slope frequency distributions, which include values in excess of regional stability limits, quasi-planar hillslopes decorated with straight, closely spaced channel-like features, and accumulation of sediment in valley networks rather than on hillslopes. Stochastic landsliding strongly affects the magnitude and timing of sediment supply to …

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Microplastics In The Marine Environment And Deep-Sea Sediment Contamination: A Review, Elizabeth Sangiolo Aug 2022

Microplastics In The Marine Environment And Deep-Sea Sediment Contamination: A Review, Elizabeth Sangiolo

Honors Program Theses and Projects

This review discusses what microplastics are and how they are continuously impacting the marine environment, and ultimately, human life. Plastic has been the number one used material for decades for industrial and recreational purposes. Its cost effectiveness, durability, and lightness are what manufacturers and consumers desire most, making plastic the most abundant pollutant in the world. Understanding how plastic pollution is broken down into microplastics and how these fragmented pieces of waste are classified can help researchers identify ways to prevent the additional input of microplastics in the marine environment. These microscopic particles of debris have been sampled from deep-sea …

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Collateral Damage: Anticoagulant Rodenticides Pose Threats To California Condors, Garth Herring, Collin A. Eagles-Smith, Rachel Wolstenholme, Alacia Welch, Chris West, Barnett A. Rattner Aug 2022

Collateral Damage: Anticoagulant Rodenticides Pose Threats To California Condors, Garth Herring, Collin A. Eagles-Smith, Rachel Wolstenholme, Alacia Welch, Chris West, Barnett A. Rattner

United States Geological Survey: Staff Publications

Anticoagulant rodenticides (ARs) are widespread environmental contaminants that pose risks to scavenging birds because they routinely occur within their prey and can cause secondary poisoning. However, little is known about AR exposure in one of the rarest avian scavengers in the world, the California condor (Gymnogyps californianus). We assessed AR exposure in California condors and surrogate turkey vultures (Cathartes aura) to gauge potential hazard to a proposed future condor flock by determining how application rate and environmental factors influence exposure. Additionally, we examined whether ARs might be correlated with prolonged blood clotting time and potential mortality …

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Mgrre_Thinsections_Mgrre-108_5, Mgrre Aug 2022

Mgrre_Thinsections_Mgrre-108_5, Mgrre

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Mgrre_Thinsections_Mgrre-108_3, Mgrre Aug 2022

Mgrre_Thinsections_Mgrre-108_3, Mgrre

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Mgrre_Thinsections_Mgrre-108_1, Mgrre Aug 2022

Mgrre_Thinsections_Mgrre-108_1, Mgrre

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Mgrre_Thinsections_Mgrre-108_6, Mgrre Aug 2022

Mgrre_Thinsections_Mgrre-108_6, Mgrre

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Mgrre_Thinsections_Mgrre-108_8, Mgrre Aug 2022

Mgrre_Thinsections_Mgrre-108_8, Mgrre

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Mgrre_Thinsections_Mgrre-108_7, Mgrre Aug 2022

Mgrre_Thinsections_Mgrre-108_7, Mgrre

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Mgrre_Thinsections_Mgrre-108_9, Mgrre Aug 2022

Mgrre_Thinsections_Mgrre-108_9, Mgrre

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Mgrre_Thinsections_Mgrre-108_11, Mgrre Aug 2022

Mgrre_Thinsections_Mgrre-108_11, Mgrre

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Mgrre_Thinsections_Mgrre-108_12, Mgrre Aug 2022

Mgrre_Thinsections_Mgrre-108_12, Mgrre

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Mgrre_Thinsections_Mgrre-108_13, Mgrre Aug 2022

Mgrre_Thinsections_Mgrre-108_13, Mgrre

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Mgrre_Thinsections_Mgrre-108_14, Mgrre Aug 2022

Mgrre_Thinsections_Mgrre-108_14, Mgrre

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Mgrre_Thinsections_Mgrre-108_15, Mgrre Aug 2022

Mgrre_Thinsections_Mgrre-108_15, Mgrre

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Mgrre_Thinsections_Mgrre-108_16, Mgrre Aug 2022

Mgrre_Thinsections_Mgrre-108_16, Mgrre

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Mgrre_Thinsections_Mgrre-108_17, Mgrre Aug 2022

Mgrre_Thinsections_Mgrre-108_17, Mgrre

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Mgrre_Thinsections_Mgrre-108_18, Mgrre Aug 2022

Mgrre_Thinsections_Mgrre-108_18, Mgrre

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Limited Rigor In Studies Of Raptor Mortality And Mitigation At Wind Power Facilities, Tara J. Conkling, Christopher J.W. Mcclure, Sandra Cuadros, Scott R. Loss, Todd E. Katzner Aug 2022

Limited Rigor In Studies Of Raptor Mortality And Mitigation At Wind Power Facilities, Tara J. Conkling, Christopher J.W. Mcclure, Sandra Cuadros, Scott R. Loss, Todd E. Katzner

United States Geological Survey: Staff Publications

Wind power is an expanding source of renewable energy. However, there are ecological challenges related to wind energy generation, including collisions of wildlife with turbines. Lack of rigor, and variation in study design, together limit efforts to understand the broad-scale effects of wind power infrastructure on wildlife populations. It is not clear, however, whether these types of limitations apply to groups of birds such as raptors that are particularly vulnerable to negative effects of wind energy. We reviewed 672 peer-reviewed publications, unpublished reports, and citations from 321 wind facilities in 12 countries to evaluate methods used to monitor and mitigate …

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Mgrre_Thinsections_Mgrre-108_2, Mgrre Aug 2022

Mgrre_Thinsections_Mgrre-108_2, Mgrre

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Mgrre_Thinsections_Mgrre-108_10, Mgrre Aug 2022

Mgrre_Thinsections_Mgrre-108_10, Mgrre

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Mgrre_Thinsections_Mgrre-108_4, Mgrre Aug 2022

Mgrre_Thinsections_Mgrre-108_4, Mgrre

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Geochronology Of Cambrian Sedimentary And Volcanic Rocks In The Illinois Basin: Defining The Illinois Aulacogen, Jared T. Freiburg, David H. Malone, Matthew Huisman Aug 2022

Geochronology Of Cambrian Sedimentary And Volcanic Rocks In The Illinois Basin: Defining The Illinois Aulacogen, Jared T. Freiburg, David H. Malone, Matthew Huisman

Faculty Publications - Geography, Geology, and the Environment

The Wabash #1 well, drilled for the Wabash CarbonSAFE Project and located in Vigo County, Indiana, USA, was drilled in early 2020 as a stratigraphic test well to characterize and evaluate the basal Cambrian Mt. Simon Sandstone for carbon dioxide storage (TD=8750 ft; 2667 m). The Wabash #1 well is located along the eastern flank of a newly interpreted Cambrian aulacogen that occurs in western Indiana and eastern Illinois. Here we present 938 new detrital zircon U-Pb ages (LA-ICPMS) from early Cambrian sandstones sampled near the base of the well. A basalt lava flow was penetrated at ~8530 ft (2600 …

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Immobilization Of Uranium And Iodine By Calcium Phosphate Minerals, Angel L. Jimenez-Arroyo Aug 2022

Immobilization Of Uranium And Iodine By Calcium Phosphate Minerals, Angel L. Jimenez-Arroyo

Theses and Dissertations

This dissertation is comprised of three independent but interconnected studies with the scope of further understanding uranium and iodine partitioning between apatite and fluid. The studies herein presented investigated: 1) brushite to apatite crystallization method; 2) the degree of uranium incorporation into apatite; 3) the degree of iodine incorporation into apatite. The importance of this work is assessing the role of apatite in immobilizing these elements, where uranium is a major component of spent nuclear fuel and iodine is a chemical analog of its radioactive isotope (129I). Once we understand the incorporation mechanisms, we will provide data that …

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Detecting Upland Glaciation In Earth’S Pre-Pleistocene Record, Gerilyn S. Soreghan, Lily Pfeifer, Dustin E. Sweet, Nicholas G. Heavens Aug 2022

Detecting Upland Glaciation In Earth’S Pre-Pleistocene Record, Gerilyn S. Soreghan, Lily Pfeifer, Dustin E. Sweet, Nicholas G. Heavens

School of Earth & Environment Departmental Research

Earth has sustained continental glaciation several times in its past. Because continental glaciers ground to low elevations, sedimentary records of ice contact can be preserved from regions that were below base level, or subject to subsidence. In such regions, glaciated pavements, ice-contact deposits such as glacial till with striated clasts, and glaciolacustrine or glaciomarine strata with dropstones reveal clear signs of former glaciation. But assessing upland (mountain) glaciation poses particular challenges because elevated regions typically erode, and thus have extraordinarily poor preservation potential. Here we propose approaches for detecting the former presence of glaciation in the absence or near-absence of …

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Geochemical Characterization Of The Louann Salt, Puma Field, Green Canyon, Gulf Of Mexico Basin – Using Xrf And Xrd, Brian Lesh Aug 2022

Geochemical Characterization Of The Louann Salt, Puma Field, Green Canyon, Gulf Of Mexico Basin – Using Xrf And Xrd, Brian Lesh

Electronic Theses and Dissertations

The Jurassic-aged Louann Salt is an evaporite sequence deposited in the Gulf of Mexico Basin (GOMB). It is an important component of the GOMB petroleum system and influences the facies pattern in overlying strata and the distribution of petroleum stratigraphic traps. The Louann Salt is composed primarily of halite with intercalated anhydrites and silty or sandy-halite intervals, with overall thicknesses in excess of four kilometers (~13,000 feet). Suture zones occur intermittently within the Louann Salt, formed by the collision of allochthonous evaporite layers. The mineralogy and geochemistry of the suture zones are currently understudied and can be hazardous during drilling …

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Regolith And Host Rock Influences On Co2 Leakage: Active Source Seismic Profiling Across The Little Grand Wash Fault, Utah, Lee M. Liberty, Jonathan Yelton, Elin Skurtveit, Alvar Braathen, Ivar Midtkandal, James P. Evans Aug 2022

Regolith And Host Rock Influences On Co2 Leakage: Active Source Seismic Profiling Across The Little Grand Wash Fault, Utah, Lee M. Liberty, Jonathan Yelton, Elin Skurtveit, Alvar Braathen, Ivar Midtkandal, James P. Evans

Geosciences Faculty Publications

Understanding carbon dioxide (CO2) reservoir to surface migration is crucial to successful carbon capture and sequestration approaches; especially fault/reservoir interactions under injection pressure. Through seismic imaging, we explore regolith and shallow stratigraphy across the Little Grand Wash fault. The presence of natural CO2 seeps, travertine and tufa deposits confirm modern and ancient fault-controlled CO2 leakage. We consider this an analogue for a long-failed sequestration site. We estimate bulk porosity and fracture density for host rock, regolith, and fault zone from petrophysical relationships. When combined with existing geochemical and geological data, we characterize a 60 m wide …

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