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Articles 5251 - 5280 of 29939

Full-Text Articles in Geology

Mgrre_Thinsections_Mgrre-108_8, Mgrre Aug 2022

Mgrre_Thinsections_Mgrre-108_8, Mgrre

Thin Sections

No abstract provided.


Mgrre_Thinsections_Mgrre-108_7, Mgrre Aug 2022

Mgrre_Thinsections_Mgrre-108_7, Mgrre

Thin Sections

No abstract provided.


Mgrre_Thinsections_Mgrre-108_9, Mgrre Aug 2022

Mgrre_Thinsections_Mgrre-108_9, Mgrre

Thin Sections

No abstract provided.


Mgrre_Thinsections_Mgrre-108_11, Mgrre Aug 2022

Mgrre_Thinsections_Mgrre-108_11, Mgrre

Thin Sections

No abstract provided.


Mgrre_Thinsections_Mgrre-108_12, Mgrre Aug 2022

Mgrre_Thinsections_Mgrre-108_12, Mgrre

Thin Sections

No abstract provided.


Mgrre_Thinsections_Mgrre-108_13, Mgrre Aug 2022

Mgrre_Thinsections_Mgrre-108_13, Mgrre

Thin Sections

No abstract provided.


Mgrre_Thinsections_Mgrre-108_14, Mgrre Aug 2022

Mgrre_Thinsections_Mgrre-108_14, Mgrre

Thin Sections

No abstract provided.


Mgrre_Thinsections_Mgrre-108_15, Mgrre Aug 2022

Mgrre_Thinsections_Mgrre-108_15, Mgrre

Thin Sections

No abstract provided.


Mgrre_Thinsections_Mgrre-108_16, Mgrre Aug 2022

Mgrre_Thinsections_Mgrre-108_16, Mgrre

Thin Sections

No abstract provided.


Mgrre_Thinsections_Mgrre-108_17, Mgrre Aug 2022

Mgrre_Thinsections_Mgrre-108_17, Mgrre

Thin Sections

No abstract provided.


Mgrre_Thinsections_Mgrre-108_18, Mgrre Aug 2022

Mgrre_Thinsections_Mgrre-108_18, Mgrre

Thin Sections

No abstract provided.


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 We reviewed 672 peer-reviewed publications, unpublished reports, and citations from 321 wind facilities in 12 countries to evaluate methods used to monitor and mitigate …


Mgrre_Thinsections_Mgrre-108_2, Mgrre Aug 2022

Mgrre_Thinsections_Mgrre-108_2, Mgrre

Thin Sections

No abstract provided.


Mgrre_Thinsections_Mgrre-108_10, Mgrre Aug 2022

Mgrre_Thinsections_Mgrre-108_10, Mgrre

Thin Sections

No abstract provided.


Mgrre_Thinsections_Mgrre-108_4, Mgrre Aug 2022

Mgrre_Thinsections_Mgrre-108_4, Mgrre

Thin Sections

No abstract provided.


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 …


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 …


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 …


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 …


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 …


Geochemical Characterization Of The Bone Spring Formation, Delaware Basin, Using Chemostratigraphy And Integrated Petrophysics, David Tonner Aug 2022

Geochemical Characterization Of The Bone Spring Formation, Delaware Basin, Using Chemostratigraphy And Integrated Petrophysics, David Tonner

Electronic Theses and Dissertations

The Delaware Basin forms part of West Texas's and New Mexico’s famous petroleum-generating Permian Basin. The Bone Spring Formation is a prolific hydrocarbon producer within this basin, creating one of the world’s richest oil shales. This formation has lithological sequences that are characterized by repeating carbonate and siliciclastic intervals of a third-order cycle which can largely be correlated to highstand and lowstand systems tracts, respectively. Lithological complexity and facies change are manifested by debris flows, turbidites, and slumps. In addition to glacio-eustasy, both tectonism and broader Milankovitch cycles have influenced the depositional history. Previous investigations have utilized cores and wireline …


Post-Fire Erosional And Hydrological Processes Promoting Debris Flow Initiation In A Douglas Fir And Western Hemlock Forest In The Riverside Burn Area, Oregon, Morena Nicole Hammer Aug 2022

Post-Fire Erosional And Hydrological Processes Promoting Debris Flow Initiation In A Douglas Fir And Western Hemlock Forest In The Riverside Burn Area, Oregon, Morena Nicole Hammer

Dissertations and Theses

Post-fire debris flows initiated by overland flow in the Pacific Northwest (PNW) are largely undocumented. Instead, debris flows are typically initiated by shallow landslides that result in a mud slurry of water and sediments traveling downhill under the force of gravity. However, because of the Fall 2020 fires in Oregon, the typical initiation style and erosional patterns in burned catchments may have changed because of unusually high burn severity. Due to the intensity of these fires, we set out to determine how hydrologic processes and erosion occurred, when they occurred, and what process was primarily responsible for the erosion that …


Investigations Of The Potential For Irrigated Agriculture On The Bonaparte Plains: Hydrogeology, Aquifer Properties And Groundwater Chemistry, Don Bennett, Paul Raper, Robert Paul, Tim Pope, Richard J. George Dr Aug 2022

Investigations Of The Potential For Irrigated Agriculture On The Bonaparte Plains: Hydrogeology, Aquifer Properties And Groundwater Chemistry, Don Bennett, Paul Raper, Robert Paul, Tim Pope, Richard J. George Dr

Resource management technical reports

‘Cockatoo Sands’ is a common name for the Cockatoo Sands family of soils (comprising red to yellowish-red sands, sandy earths, and loamy earths) that have formed from quartz sandstone colluviums in relatively isolated patches throughout the East Kimberley region of Western Australia and the Northern Territory. Cockatoo Sands are recognised as potentially suitable for irrigated agriculture because they are generally well drained and not subject to waterlogging or inundation. These characteristics allow them to be cultivated and prepared for planting various crops during the wet and dry seasons of northern Australia.

Expanding agricultural production onto the Cockatoo Sands around Kununurra …


Application Of A 14c-Assay To Assess Methanotrophic Biodegradation Of Tce In Low Ph Groundwater, Evan Groome Aug 2022

Application Of A 14c-Assay To Assess Methanotrophic Biodegradation Of Tce In Low Ph Groundwater, Evan Groome

All Theses

Current biological strategies for remediating trichloroethylene (TCE) in low pH aquifers (i.e., pH14C-TCE assay was developed to determine pseudo first-order rate constants for the degradation of TCE in microcosms containing soil and groundwater from the Boeing Michigan Aeronautical Research Center (BOMARC) superfund site, where the pH ranges from 4.1 to 4.9. The 14C-TCE assay was also adapted to calculate soil-normalized rate constants for data from this site, as well as data that Szwast21 collected from the Beltsville Agricultural Research Center (BARC). In addition to natural attenuation, biostimulation through amendments of methane and nutrients were also assessed. This treatment …


Natural And Experimental Slow Slip Observed Along Shallow Hematite Faults, Alexandra A. Dimonte Aug 2022

Natural And Experimental Slow Slip Observed Along Shallow Hematite Faults, Alexandra A. Dimonte

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

Fault slip relieves stress in the shallow crust by slipping suddenly during earthquakes, but some faults also slip slowly in between earthquakes. Exhumed faults, brought up to the Earth’s surface from depth, preserve a record of fault processes and slip rates informed by fault rock structures, textures, and chemistry. Hematite, a common iron oxide mineral that precipitates on fault surfaces, exhibits crystal textures that potentially indicate past slip rate. Hematite can be dated using the radioisotopic system of (U-Th)/He thermochronometry, which constrains the time when He is trapped within a crystal, a process that is a function of temperature. Exhumed …


The Curacautín Eruption Of Llaima Volcano, Chile, Aaron Asdale Marshall Aug 2022

The Curacautín Eruption Of Llaima Volcano, Chile, Aaron Asdale Marshall

Boise State University Theses and Dissertations

Mafic magmas are the most common magmas erupted on Earth and on rocky bodies in the Solar System. The low viscosity of mafic magmas results in eruptions that are primarily effusive to mildly explosive. Rarely, mafic magmas erupt as more violent, explosive events, and the causes of this transition in eruptive style are hotly debated. In this dissertation, I investigated the conditions in the conduit and shallow subsurface that generated the unusually explosive mafic, Curacautín eruption of Llaima volcano, Chile. The Curacautín ignimbrite (Ci) is a basaltic andesite ignimbrite consisting of four flow units of variable thicknesses. New 14C …


Machine-Learning Reveals Aftershock Locations For Three Idaho Earthquake Sequences, Spencer F. Wilbur Aug 2022

Machine-Learning Reveals Aftershock Locations For Three Idaho Earthquake Sequences, Spencer F. Wilbur

Boise State University Theses and Dissertations

I explore spatial and temporal aftershock patterns related to three instrumentally recorded earthquakes in Idaho -- the Sulphur Peak, the Challis, and the Stanley earthquakes. These three M > 5 earthquakes border the eastern Snake River Plain and lie within the Intermountain Seismic Belt and Centennial Tectonic Belt. Using machine learning for event detection and phase picking from local and regional seismic networks, I generate new aftershock catalogs. I locate more aftershocks than in the USGS catalog due to lower signal-to-noise detections. Using my phase picks, I locate aftershocks using a range of velocity models and select a catalog that represents …


Evaluation Of Carbon Isotopic Chemostratigraphy Of The Cedar Mountain Formation Of Utah, Clayton Forster Aug 2022

Evaluation Of Carbon Isotopic Chemostratigraphy Of The Cedar Mountain Formation Of Utah, Clayton Forster

Graduate Theses and Dissertations

The Lower Cretaceous rocks of Utah preserve the origin of a multitude of dinosaur taxa, spread of angiosperms on the North American continent, and evolution of marsupial and eutherian mammals. However, the timing of deposition of these rocks is not well understood and must be determined to understand climatic controls on these biological events. Estimates of the age of the Cedar Mountain Formation and its constituent members range from Late Jurassic to early Late Cretaceous. Understanding the timing of deposition of the Cedar Mountain Formation is critical to dinosaurian and associated taxa studies as well as paleoclimate reconstructions from within …


A Faunal Composition Of The Late Cretaceous Blue Springs Site In Northeastern Mississippi And Evidence For Potential Paleoenvironmental Differences Between Beds, Ginger Trochesset Aug 2022

A Faunal Composition Of The Late Cretaceous Blue Springs Site In Northeastern Mississippi And Evidence For Potential Paleoenvironmental Differences Between Beds, Ginger Trochesset

Honors Theses

The Maastrichtian-age Blue Springs locality of the Coon Creek Member of the Ripley Formation is known for abundant, well-preserved marine fossils, including many genera of microfossils, bivalves, gastropods, decapods, cephalopods, actinopterygians, and other vertebrate organisms. This research contributes to the understanding of the paleontology of the site, as well as the changing paleoenvironmental conditions of the beds throughout deposition.

This project analyzed bulk material collected in 2021 from three fossiliferous beds at Blue Springs: the Lower Corbula Bed (Bed C), the Pebble Bed (Bed G), and the Exogyra-Pycnodonte Bed (Bed J). Unconsolidated material from Beds C and J was processed …


Faunal Comparison And Analysis Of The Blufftown Formation-Cusseta Sand Contact At Hannahatchee Creek, Georgia, Seth Fradella Aug 2022

Faunal Comparison And Analysis Of The Blufftown Formation-Cusseta Sand Contact At Hannahatchee Creek, Georgia, Seth Fradella

Honors Theses

The origin of fossil material in the highly fossiliferous bed above the Upper Cretaceous (Campanian) Blufftown Formation-Cusseta Sand contact at Hannahatchee Creek, Georgia, has long been a subject of scientific curiosity; however, no research has yet been conducted to specifically investigate discrepancies between the fossil assemblages of the upper Blufftown Formation and the basal Cusseta Sand, which overlies it unconformably. In the most recent published hypothesis, Case and Schwimmer (1988) propose that the basal Cusseta Sand contains a mixture of original fauna as well as material reworked and redeposited from the underlying Blufftown Formation, resulting in a lag deposit above …