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

Geology Commons™

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

2022

Discipline
Institution
Keyword
Publication
Publication Type
File Type

Articles 4381 - 4410 of 5201

Full-Text Articles in Geology

Factors Influencing Tree Growth In A Bottomland Hardwood Along The Green River In Kentucky, Caleb Miller May 2022

Factors Influencing Tree Growth In A Bottomland Hardwood Along The Green River In Kentucky, Caleb Miller

Masters Theses & Specialist Projects

In bottomland hardwood forests, large fluctuations in moisture availability can lead to stress from both flooded and drought conditions. These forests can have a complex species composition with different water use and drought strategies. The bottomlands in which these species co-occur can have a complex spatial distribution of alluvial sediments due to the meandering and migration of river or stream channels, which may impact the hydrology, nutrient dynamics, and productivity. At Western Kentucky University's Green River Preserve, approximately 9 ha of bottomland hardwood forest were planted in 2006. Although these hardwoods have received equal amounts of sunlight, rainfall, and wind, …

Go to article

A Step Toward Reconstructing Climate Variability Druing The Last Ice Age Cycle In The Northeast Pacific Region, Blaine Lynch-Gadaleta May 2022

A Step Toward Reconstructing Climate Variability Druing The Last Ice Age Cycle In The Northeast Pacific Region, Blaine Lynch-Gadaleta

Senior Honors Projects

This study is designed as a step toward reconstructing the climate variability in the Northeast Pacific during the last ice age cycle, including the glacial and deglacial transitions. Reconstruction may also contribute to the regional picture of climate change and potentially provide new insights into the pattern of variability in the Northeast Pacific. Deep-sea sediment core AT26-19 09PC was collected west of the Juan de Fuca Ridge in the Northeast Pacific Ocean. Samples were analyzed in 1 cm intervals, representing approximately 300-year resolution. The abundance of mineral grains, planktonic foraminifera, and the polar foraminifera N.pachyderma was quantified using split aliquots …

Go to article

Shallow Composition And Structure Of The San Gabriel Fault, California In Drill Core And Geophysical Logs: Implications For Fault Slip And Energetics, Kaitlyn A. Crouch May 2022

Shallow Composition And Structure Of The San Gabriel Fault, California In Drill Core And Geophysical Logs: Implications For Fault Slip And Energetics, Kaitlyn A. Crouch

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

Earthquakes are the sudden and intensive release of energy due to slip along faults. This energy may be felt on the Earth’s surface and may cause displacement of the Earth’s crust (seismic slip). As an earthquake ruptures, rocks in and around the fault are damaged and altered. When a fault displaces without earthquakes, it is referred to as aseismic creep. Faults may experience both seismic slip and aseismic creep throughout their cycles. In order to better model earthquake hazards and understand the cause of seismic slip versus aseismic creep in the shallow crust, we need to characterize the properties of …

Go to article

Identifying The Isotopic Signature Of Lake-Effect Precipitation In Shallow Groundwater, Andrew Brown May 2022

Identifying The Isotopic Signature Of Lake-Effect Precipitation In Shallow Groundwater, Andrew Brown

Honors Projects

Three different stable isotopes of water occur in nature, with the majority of water on Earth containing the oxygen isotope 16O. These isotopes have slightly differing physical and chemical properties. H2O with heavier oxygen isotopes should theoretically precipitate earlier than lighter isotope H2O, meaning this natural process should allow for the observation of the magnitude of effects of lake-effect precipitation on the basis of water isotope differences. Furthermore, it may allow for better understanding of the significance lake-effect precipitation plays in recharging shallow aquifers. In this study, patterns of lake-effect precipitation from Lake Michigan were observed in a collection of …

Go to article

Core-Cm Williston Basin Carbon Ore, Rare Earth, And Critical Minerals, University Of North Dakota. Energy And Environmental Research Center May 2022

Core-Cm Williston Basin Carbon Ore, Rare Earth, And Critical Minerals, University Of North Dakota. Energy And Environmental Research Center

EERC Brochures and Fact Sheets

Fact sheet on the Carbon Ore, Rare Earth and Critical Minerals (CORE-CM) Initiative, an Energy & Environmental Research Center and U.S. Department of Energy project. Includes information on the importance of critical minerals and utilizing lignite from the Williston Basin. [This item is an outdated or superseded version and retained for historical purposes only. It may no longer reflect current information, policies, or practices.]

Go to article

Computational Approaches To Understanding Subduction Zone Geodynamics, Surface Heat Flow, And The Metamorphic Rock Record, Buchanan C. Kerswell May 2022

Computational Approaches To Understanding Subduction Zone Geodynamics, Surface Heat Flow, And The Metamorphic Rock Record, Buchanan C. Kerswell

Boise State University Theses and Dissertations

Pressure-temperature (PT) estimates from exhumed high-pressure (HP) metamorphic rocks and global surface heat flow observations evidently encode information about subduction zone thermal structure and the nature of mechanical and chemical processing of subducted materials along the interface between converging plates. Previous work demonstrates the possibility of decoding such geodynamic information by comparing numerical geodynamic models with empirical observations of surface heat flow and the metamorphic rock record. However, ambiguous interpretations can arise from this line of inquiry with respect to thermal gradients, plate coupling, and detachment and recovery of subducted materials. This dissertation applies a variety of computational techniques to …

Go to article

A Geochemical And Mineralogical Evaluation Of The Mona Lisa Turquoise Mine, Polk County, Arkansas, Alexander Arai Goodsuhm May 2022

A Geochemical And Mineralogical Evaluation Of The Mona Lisa Turquoise Mine, Polk County, Arkansas, Alexander Arai Goodsuhm

Graduate Theses and Dissertations

The presence of turquoise in Arkansas has long been disputed by geologists and gem collectors. Despite the prevalence of other phosphate minerals in Arkansas, such as planerite, wavellite, and variscite, the absence of an obvious copper (Cu) source required for turquoise formation was considered too great of an obstacle for turquoise mineralization. In this study, geologic, mineralogical, and geochemical techniques provide overwhelming evidence that the novaculite-hosted Mona Lisa Mine in Arkansas does produce turquoise. X-ray diffraction and Raman spectroscopy have confirmed the structural nature of the material and identified other phosphate minerals, such as crandallite, often found in assemblage with …

Go to article

Characterization And Evolution Of The Professor Valley Pennsylvanian Salt Body (Paradox Basin, Ut) Using Gravity And Magnetotellurics, Derek Scott May 2022

Characterization And Evolution Of The Professor Valley Pennsylvanian Salt Body (Paradox Basin, Ut) Using Gravity And Magnetotellurics, Derek Scott

Open Access Theses & Dissertations

Syndepositional halokinetic movement of the Pennsylvanian Paradox Formation in the Paradox Basin, UT & CO behaved as a control over the development of depositional systems during the Late Paleozoic and early Mesozoic periods (Trudgill, 2011). Understanding the controls on halokinetic evolution in the area serves as an invaluable outcrop analogue for similar subsurface salt bodies in petroleum-bearing basins and provides key insights for hydrocarbon exploration in salt basins world wide. Professor Valley, located 15 miles Northeast of Moab, UT is situated between the Fisher Valley (Onion Creek) and Cache/Salt Valley salt walls. It includes an anomalous, isolated 0.5 km² outcrop …

Go to article

Air, Land, And Water Variables Associated With The First Appearance And Current Spatial Distribution Of Toxic Prymnesium Parvum Blooms In Reservoirs Of The Southern Great Plains, Usa, Shisbeth Tábora-Sarmiento, Reynaldo Patiño, Carlos Portillo-Quintero, Cade Coldren Apr 2022

Air, Land, And Water Variables Associated With The First Appearance And Current Spatial Distribution Of Toxic Prymnesium Parvum Blooms In Reservoirs Of The Southern Great Plains, Usa, Shisbeth Tábora-Sarmiento, Reynaldo Patiño, Carlos Portillo-Quintero, Cade Coldren

United States Geological Survey: Staff Publications

This study examined the association of air, land, and water variables with the first historical occurrence and current distribution of toxic Prymnesium parvum blooms in reservoirs of the Brazos River and Colorado River, Texas (USA). One impacted and one reference reservoir were selected per basin. Land cover and use variables were estimated for the whole watershed (WW) and a 0.5-km zone on either side of streams (near field, NF). Variables were expressed in annual values. Principal component and trend analyses were used to determine (1) differences in environmental conditions before and after the 2001 onset of toxic blooms in impacted …

Go to article

Quantitative Analysis Of The Maximum Rate And Minimum Duration For A 200 Km Stepwise Retreat Of The Bindschadler Ice Stream At ~11.5 Cal Kyr Bp, Matthew E Kratochvil Apr 2022

Quantitative Analysis Of The Maximum Rate And Minimum Duration For A 200 Km Stepwise Retreat Of The Bindschadler Ice Stream At ~11.5 Cal Kyr Bp, Matthew E Kratochvil

LSU Master's Theses

Small-scale morainal ridges on the middle continental shelf of the Whales Deep Basin partly record the rapid opening of a 200-km grounding line embayment slightly after ~11.5 cal kyr BP. The overlapping pattern of backstepped moraines indicates that the grounding line oscillated back and forth during the retreat. Published sediment fluxes were combined with new sediment volume mapping of the moraines to infer the rates at which the grounding line retreated. The analyses indicate that the rates of grounding line retreat on the eastern flank of the embayment ranged from ~490 m a-1 to 1,300 m a-1. …

Go to article

Impact Of Traditional Versus Alternative Assessment On Student Achievement, Beth Lustgarten Apr 2022

Impact Of Traditional Versus Alternative Assessment On Student Achievement, Beth Lustgarten

Honors Projects

The focus of this study looks at the effect of alternative assessment on student achievement in a high school science classroom. Within this action research, students have choices and are able to demonstrate creativity in their alternative assessments. By comparing student results from traditional and alternative assessments, the impact of assessment showed students had an overwhelming preference for completing alternative assessments, and a majority of students did better on the alternative assessment when compared to the traditional assessment.

Go to article

The Geology Of The Mt. Simon Sandstone Storage Complex At The Wabash #1 Well, Vigo Co., Indiana (Subtask 7.2, Technical Report), Jared T. Freiburg, Franck Delpomdor, John H. Mcbride, Hannes E. Leetaru, David H. Malone, Nate Grigsby, Mansour Khosravi, Scott Frailey, James R. Damico, Charles Monson, Zohreh Askari, Yaghoob Lasemi, Donna Willette, Oladipupo Babarinde, Chris Korose, Mingyue Yu, Lauren Gardiner Apr 2022

The Geology Of The Mt. Simon Sandstone Storage Complex At The Wabash #1 Well, Vigo Co., Indiana (Subtask 7.2, Technical Report), Jared T. Freiburg, Franck Delpomdor, John H. Mcbride, Hannes E. Leetaru, David H. Malone, Nate Grigsby, Mansour Khosravi, Scott Frailey, James R. Damico, Charles Monson, Zohreh Askari, Yaghoob Lasemi, Donna Willette, Oladipupo Babarinde, Chris Korose, Mingyue Yu, Lauren Gardiner

Faculty Publications - Geography, Geology, and the Environment

The Wabash CarbonSAFE project drilled the Wabash #1 stratigraphic test well (ID# 168045) at the Wabash Valley Resources (WVR) IGCC facility in Vigo County, Indiana, to characterize and evaluate the basal Cambrian Mt. Simon Sandstone for commercial-scale CO2 storage near the site. This report presents an extensive geologic characterization of the Mt. Simon storage complex and relevant data collected from the Wabash #1 well, such as lithologic data collected from cuttings and core, geophysical logging, geomechanical analysis of core samples, and well testing and fluid sampling within the Mt. Simon Sandstone. The Mt. Simon storage complex comprises two major sections: …

Go to article

Spatial And Temporal Distribution And Habitat Selection Of Native Yellowstone Cutthroat Trout And Nonnative Utah Chub, Darcy K. Mccarrick, Jeffrey C. Dillon, Brett High, Michael C. Quist Apr 2022

Spatial And Temporal Distribution And Habitat Selection Of Native Yellowstone Cutthroat Trout And Nonnative Utah Chub, Darcy K. Mccarrick, Jeffrey C. Dillon, Brett High, Michael C. Quist

United States Geological Survey: Staff Publications

Henrys Lake, Idaho, is a renowned trophy trout fishery that faces an uncertain future following the establishment of Utah Chub (UTC) Gila atraria. Utah Chub were first documented in the lake in 1993 and have become abundant over the past two decades. Little is known about the ecology of UTC, but they typically have negative effects on salmonids in systems where they have been introduced. We sought to fill knowledge gaps in UTC ecology and provide insight on potential interactions with Yellowstone Cutthroat Trout (YCT) Oncorhynchus clarkii bouvieri. Ninety-four YCT and 95 UTC were radio-tagged in spring 2019 …

Go to article

Connections Between Interglacial Variation And Lithological Variability Within Midland Basin Permian Shale Rocks In Martin County, Texas, Helen Rice Hammon Apr 2022

Connections Between Interglacial Variation And Lithological Variability Within Midland Basin Permian Shale Rocks In Martin County, Texas, Helen Rice Hammon

LSU Master's Theses

The Upper Pennsylvanian (323.2–289.9 Ma) and Lower Permian (289.9-251 Ma), (Wolfcamp and Spraberry formations) interval of the Midland Basin, West Texas, contains a mixed succession of shale, carbonate, and siltstone/sandstone lithofacies that accumulated in a deep-water marine environment under variable hydrographic restrictions. The heterogenous stratigraphy found in the Wolfcamp and Spraberry formation was formed in response to variations in sea level and a transition from a glacial to an interglacial climate during the Early Permian. These fluctuations left behind alternating beds of mudstone and carbonate, interwoven with thin sandstone beds. Because the Wolfcamp and Spraberry formations are highly heterolithic, it …

Go to article

Geo 100: Environmental Geology Oer Curation, Chealsye Bowley Apr 2022

Geo 100: Environmental Geology Oer Curation, Chealsye Bowley

Curated OER Collections

This OER curation is an annotated bibliography of prospective OER for the GVSU course GEO 100: Environmental Geology.

Go to article

Presence Or Absence Of Microcystins Within The Lake Macatawa Watershed, Keiley M. Hoving, Garrett E. Peck Apr 2022

Presence Or Absence Of Microcystins Within The Lake Macatawa Watershed, Keiley M. Hoving, Garrett E. Peck

21st Annual Celebration of Undergraduate Research and Creative Activity (2022)

Cyanobacteria, commonly known as blue-green algae, are freshwater aquatic microorganisms that are important indicators of climate change. They also release microcystins: toxins that can cause sickness, organ failure, or even death in plants, animals and humans. Studies have monitored microcystin presence and concentration in large-scale Cyanobacterial blooms, such as in Lake Erie, but often omit smaller scale instances. This project determines whether or not microcystins are present in the Lake Macatawa Watershed and identifies important conditional factors associated with microcystin presence to conclude if harmful algal blooms like those of Lake Erie are plausible locally. Six sample locations along the …

Go to article

Connecting Chemical Composition And Methane Production In A West Michigan Peatland, Rachel Shaw, Grace Behrens, Lauren Bryan, Alexis Koehl, Christian Lundy Apr 2022

Connecting Chemical Composition And Methane Production In A West Michigan Peatland, Rachel Shaw, Grace Behrens, Lauren Bryan, Alexis Koehl, Christian Lundy

21st Annual Celebration of Undergraduate Research and Creative Activity (2022)

The future net radiative forcing of peatlands will depend in large part on changes in methane emissions. However, current climate models lack a mechanistic representation of methane production. We conducted an anaerobic incubation experiment using peat from various depths in five cores collected from a West Michigan peatland in order to connect methane production to observable differences in the chemical composition of peat and peat pore water. We hypothesized that less decomposed peat may have a larger supply of fermentable sugars that can thus produce more methane than more decomposed peat. C:N, hydrolyzable amino acids, and neutral sugars were analyzed …

Go to article

Carbon Storage And Methane Production From Interdunal Wetlands In Saugatuck Harbor Natural Area, Grace Behrens Apr 2022

Carbon Storage And Methane Production From Interdunal Wetlands In Saugatuck Harbor Natural Area, Grace Behrens

21st Annual Celebration of Undergraduate Research and Creative Activity (2022)

Wetlands have a dual impact on the climate: a cooling effect caused by organic matter accumulation in anoxic sediments (removing carbon dioxide from the atmosphere); and a warming effect caused by methane emissions from these sediments. In this study, we analyzed the relative importance of both processes in interdunal wetlands in the Saugatuck Harbor Natural Area (SHNA). The SHNA wetlands are a unique ecosystem, dependent on high water levels in Lake Michigan. Thus, carbon accumulation in the wetlands may be ephemeral as the lake level falls. Our goal in this study was to evaluate the extent of carbon accumulation in …

Go to article

Terrestrial Trash Taphonomy: Characterizing Roadside Litter As Potential Sources Of Plastic In Waterways, Kailey M. Hoving, Kelly J. Gotham Apr 2022

Terrestrial Trash Taphonomy: Characterizing Roadside Litter As Potential Sources Of Plastic In Waterways, Kailey M. Hoving, Kelly J. Gotham

21st Annual Celebration of Undergraduate Research and Creative Activity (2022)

We collected and characterized roadside litter from 300 m transects along 4 streets in Holland, Michigan that included stream crossings or storm drain inlets. Opposite sides of 3 roads were collected as separate sampling sites, and 4 of these were resampled after ~30 days, yielding 11 different collections. Litter was unevenly distributed within single transects, with some concentrations of litter (e.g., car parts, styrofoam) apparently resulting from single, localized releases of material. Despite such idiosyncratic occurrences, factor analysis of collected items placed associated sites (opposite sides of roads and resampled sites) in non-overlapping domains. Of 11,223 items analyzed, 83.2% were …

Go to article

*Interactive Earthquake Visualization With Open Data, Matous Hybl Apr 2022

*Interactive Earthquake Visualization With Open Data, Matous Hybl

Campus Research Month

Because earthquakes claim thousands of lives and billions of dollars yearly, there is a great need to recognize patterns in seismic data. While some tools for analysis exist, most geological software is expensive and open earthquake visualizations are limited. In this project, we provide accessible earthquake visualizations aimed to encourage geologists, and science enthusiasts in general, to explore open data using accessible, yet powerful, tools.

Go to article

Connections Between Interglacial Variation And Lithological Variability Within Midland Basin Permian Shale Rocks In Martin County, Texas, Helen Rice Hammon Apr 2022

Connections Between Interglacial Variation And Lithological Variability Within Midland Basin Permian Shale Rocks In Martin County, Texas, Helen Rice Hammon

LSU Master's Theses

The Upper Pennsylvanian (323.2–289.9 Ma) and Lower Permian (289.9-251 Ma), (Wolfcamp and Spraberry formations) interval of the Midland Basin, West Texas, contains a mixed succession of shale, carbonate, and siltstone/sandstone lithofacies that accumulated in a deep-water marine environment under variable hydrographic restrictions. The heterogenous stratigraphy found in the Wolfcamp and Spraberry formation was formed in response to variations in sea level and a transition from a glacial to an interglacial climate during the Early Permian. These fluctuations left behind alternating beds of mudstone and carbonate, interwoven with thin sandstone beds. Because the Wolfcamp and Spraberry formations are highly heterolithic, it …

Go to article

Hot Rocks: Constraining The Thermal Conditions Of The Mistastin Lake Impact Melt Deposits Using Zircon Grain Microstructures, Gavin Douglas Tolometti, Timmons M. Erickson, Gordon R. Osinski, Cyril Cayron, Catherine Neish Apr 2022

Hot Rocks: Constraining The Thermal Conditions Of The Mistastin Lake Impact Melt Deposits Using Zircon Grain Microstructures, Gavin Douglas Tolometti, Timmons M. Erickson, Gordon R. Osinski, Cyril Cayron, Catherine Neish

Earth Sciences Publications

The production of superheated melt during hypervelocity impact events has been proposed to be a common occurrence on terrestrial planetary bodies. Recent direct evidence of superheated impact melt temperatures exceeding >2370°C from the Kamestastin (Mistastin Lake) impact structure, Canada, was based on a single impact glass sample. Such high superheated melt temperatures have strong implications for the evolution of crustal material, the thermal history of impact cratering events, and the rheology of impact melt. However, although widely predicted in previous studies, with the exception of the Mistastin Lake impact glass, there is little direct evidence for superheated temperatures in multiple …

Go to article

Gps Observations Of Subsidence In South Louisiana Over Seasonal And Sub-Seasonal Timescales Associated With Hydrologic Loading, Nicholas Schuler Apr 2022

Gps Observations Of Subsidence In South Louisiana Over Seasonal And Sub-Seasonal Timescales Associated With Hydrologic Loading, Nicholas Schuler

LSU Master's Theses

Louisiana’s primary environmental concern is arguably coastal wetland loss due to high subsidence rates, previously estimated to range from 1-14 mm/yr across much of the coast. Spatially and temporally varying strong short-term and seasonal components of deformation associated with changes in hydrologic loading throughout the year can give information about the elastic properties of the shallow crust, having implications for better understanding long-term subsidence trends across the region. Therefore, we quantify and characterize vertical deformation that occurs on annual to sub-annual timescales across southeast Louisiana. Vertical deformation is evaluated using publicly available daily GPS positions from 2016–2020 at 16 stations …

Go to article

Systematic Paleontology, Acritarch Biostratigraphy, And Δ13c Chemostratigraphy Of The Early Ediacaran Krol A Formation, Lesser Himalaya, Northern India, Shuhai Xiao, Ganqing Jiang, Qin Ye, Qing Ouyang, Dhiraj M. Banerjee, Birendra P. Singh, A. D. Muscente, Chuanming Zhou, Nigel C. Hughes Apr 2022

Systematic Paleontology, Acritarch Biostratigraphy, And Δ13c Chemostratigraphy Of The Early Ediacaran Krol A Formation, Lesser Himalaya, Northern India, Shuhai Xiao, Ganqing Jiang, Qin Ye, Qing Ouyang, Dhiraj M. Banerjee, Birendra P. Singh, A. D. Muscente, Chuanming Zhou, Nigel C. Hughes

Geoscience Faculty Research

Acritarch biostratigraphic and δ13C chemostratigraphic data from the Krol A Formation in the Solan area (Lesser Himalaya, northern India) are integrated to aid inter-basinal correlation of early–middle Ediacaran strata. We identified a prominent negative δ13C excursion (likely equivalent to EN2 in the lower Doushantuo Formation in the Yangtze Gorges area of South China), over a dozen species of acanthomorphs (including two new species—Cavaspina tiwariae Xiao n. sp., Dictyotidium grazhdankinii Xiao n. sp.), and numerous other microfossils from an interval in the Krol A Formation. Most microfossil taxa from the Krol A and the underlying Infra-Krol formations are also present in …

Go to article

Comparing Satellite Vs Marine Potential Fields Data Over The Bathymetrists Seamounts, Alexa Fernandez, Irina Filina Apr 2022

Comparing Satellite Vs Marine Potential Fields Data Over The Bathymetrists Seamounts, Alexa Fernandez, Irina Filina

UNL Student Research Days Posters, Graduate

The Bathymetrists Seamounts (BSM) are located north of the Sierra Leone Rise (SLR) in the mid-Atlantic Ocean. The seamounts reside on oceanic crust that is 105 to 45 million years old. However, dredging over the Bathymetrists Seamounts dated rocks at ~40 Myr. The general trend of the seamounts contradicts the eastward motion of the African tectonic plate. The origin and tectonic history of the Bathymetrists Seamounts remains debated in literature. Potential fields (gravity and magnetic) data can provide important insight into the formation and evolution of the seamounts. The purpose of this study is to compare available gravity and magnetic …

Go to article

Sediment Buffering And Recycling On An Annual To Centennial Scale Along The Mississippi River, Nikki E. Neubeck Apr 2022

Sediment Buffering And Recycling On An Annual To Centennial Scale Along The Mississippi River, Nikki E. Neubeck

LSU Master's Theses

Although the Mississippi River and its tributaries have been investigated for many years, the alteration of the river through dams, levees, and diversions has affected how sediment is transported from source to sink (>103 y). Previous provenance research using detrital zircon U-Pb dating indicates a slow transport time from source-to-sink, but recent anthropogenic alterations of the river may potentially diminish the transportation time of heavy minerals due to an increase in flow efficiency. The objective of this study is to analyze the degree of buffering and recycling of Mississippi River sediment over a range of short time scales, …

Go to article

Isotopic Analysis Of Hydrous Phenocrysts In Lava Flows Of The Peruvian Altiplano Plateau: Testing For A Subduction Signature, Alyssa Schiwal Apr 2022

Isotopic Analysis Of Hydrous Phenocrysts In Lava Flows Of The Peruvian Altiplano Plateau: Testing For A Subduction Signature, Alyssa Schiwal

Student Research Symposium

The process of flat-slab subduction introduces fluids directly into the overlaying lithosphere, leaving behind a unique stable isotope and trace element signature to the surrounding crust/mantle. Fluid alteration of the deep lithosphere can help explain geologic processes that are observed at the surface, such as patterns of crustal deformation (mountain building) and volcanism. The young high-K mafic volcanic rocks found in the Altiplano region of Southern Peru are derived from the melting of an altered mantle source. By analyzing the hydrogen stable isotopes as well as the trace elements of these volcanic rocks we can locate the water source associated …

Go to article

Thickness Of Fluvial Deposits Records Climate Oscillations, Xiaoping Yuan, Laure Guerit, Jean Braun, Delphine Rouby, Charles Shobe Apr 2022

Thickness Of Fluvial Deposits Records Climate Oscillations, Xiaoping Yuan, Laure Guerit, Jean Braun, Delphine Rouby, Charles Shobe

Faculty & Staff Scholarship

Fluvial deposits offer Earth’s best-preserved geomorphic record of past climate change over geological timescales. However, quantitatively extracting this information remains challenging in part due to the complexity of erosion, sediment transport and deposition processes and how each of them responds to climate. Furthermore, sedimentary basins have the potential to temporarily store sediments, and rivers subsequently rework those sediments. This may introduce time lags into sedimentary signals and obscure any direct correlation with climate forcing. Here, using a numerical model that combines all three processes—and a new analytical solution—we show that the thickness of fluvial deposits at the outlet of a …

Go to article

Detecting Climate Change In Trilobite Time, Michelle Norman Apr 2022

Detecting Climate Change In Trilobite Time, Michelle Norman

Student Research Symposium

Trilobites are a signature marine fossil of the Cambrian explosion, which took place about 500 Ma (million years ago). By studying these fossiliferous rocks (limestone), we can get an understanding of ecological and environmental change. In fact, we can detect the ancient carbon cycle by measuring stable carbon isotopes in these limestone samples. By studying the carbon environment the trilobites lived in and which trilobite species evolve or go extinct, we can learn more about ancient climate events and constrain them to a certain period of time based off the age of radioactive zircons we find in sandy material around …

Go to article

Jillson, Willard Rouse, 1890-1975 (Mss 682), Manuscripts & Folklife Archives Apr 2022

Jillson, Willard Rouse, 1890-1975 (Mss 682), Manuscripts & Folklife Archives

Manuscript Collection Finding Aids

Finding aid only for Manuscripts Collection 682. Writings and supporting materials of Willard Rouse Jillson, State Geologist of Kentucky, author and historian. Includes manuscripts, page proofs, photographic negatives, and promotional pamphlets for his books.

Go to article

First Prev Next Last