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Full-Text Articles in Geology

Carbon-Isotope Chemostratigraphy And Fluvial Sedimentology Of The Moenave Formation, Utah, Jordan Oefinger May 2021

Carbon-Isotope Chemostratigraphy And Fluvial Sedimentology Of The Moenave Formation, Utah, Jordan Oefinger

Graduate Theses and Dissertations

The end Triassic extinction (ETE) is one of the largest mass extinction events of the Phanerozoic, and it has been hypothesized that this event, as well as the Triassic-Jurassic (TJ) boundary, are preserved within the Moenave Formation of the Colorado Plateau. Identification of this boundary within southwest Utah sections of the Colorado Plateau region is critical for better understanding the relationship between climate change and the ETE in terrestrial, low latitude paleoenvironments. The Moenave Formation is well exposed in Blacks Canyon of Zion National Park and in the nearby Warner Valley, where detailed sedimentologic observations and carbon isotope sampling have …


Gravel Geology And Muskoxen Paleontology Of A Late Pleistocene Fossil Site In Saltville, Virginia, Nickolas A. Brand May 2021

Gravel Geology And Muskoxen Paleontology Of A Late Pleistocene Fossil Site In Saltville, Virginia, Nickolas A. Brand

Electronic Theses and Dissertations

Two distinct studies within the Saltville Valley of southwestern Virginia revealed insights into local Pleistocene geology and paleontology. A variety of analytical techniques were applied to gravel deposits within the paleontological site of SV-5/7 that revealed this unit is very poorly sorted, has a subangular matrix, and contains significant components of silt and sand in addition to rounded cobbles. These results suggest that rather than being deposited by fluvial processes as previously suggested, these gravels were likely the result of one or many debris flows. Additionally, the identity of fossil muskoxen from Saltville was reassessed using cranial and dental material. …


Prograde Metamorphism And Upper-Crustal Cooling In The Northern Panamint Range, California: New Insights Into The Jurassic And Mid-Cretaceous Evolution Of The Southern Sevier Fold-Thrust Belt, Elijah A. Turner May 2021

Prograde Metamorphism And Upper-Crustal Cooling In The Northern Panamint Range, California: New Insights Into The Jurassic And Mid-Cretaceous Evolution Of The Southern Sevier Fold-Thrust Belt, Elijah A. Turner

UNLV Theses, Dissertations, Professional Papers, and Capstones

The Jurassic-Cretaceous southern Sevier fold-thrust belt, which experiences changes in orientation and structural style as it approaches intersection with the Mesozoic continental arc, has been pervasively overprinted by Neogene-Quaternary faulting, rendering its evolution enigmatic. Raman spectroscopy of carbonaceous material (RSCM) thermometry data from 14 samples and zircon (U-Th)/He (ZHe) thermochronology data from 23 samples collected in the northern Panamint Range illuminate the history of metamorphism and upper-crustal cooling associated with this belt of shortening structures. Best estimate peak temperatures derived from RSCM thermometry increase from 166 ± 19°C at 2.5 km structural depth (measured from the top of the exposed …


The Biggest Snowball Fight In Earth History: Stratigraphy, Facies Analysis, And Geochronology Of The Pocatello Formation, Matthew W. Ellison May 2021

The Biggest Snowball Fight In Earth History: Stratigraphy, Facies Analysis, And Geochronology Of The Pocatello Formation, Matthew W. Ellison

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

The Snowball Earth Hypothesis details a time in Earth’s history (the Cryogenian period) where the entire planet was encapsulated by kilometer thick ice sheets for two, multi-million-year glaciations. The first, known as the Sturtian, lasted from 717 – 660 million years ago while the second, known as the Marinoan, lasted form approximately 650 – 635 million years ago. Snowball Earth was caused by a few processes that sort of built upon each other: Rodinia began splitting apart ~740 million years ago which allowed for increased rates of silicate weathering. High rates of silicate weathering resulted in CO2 drawdown which …


Spatial And Temporal Patterns Of River Incision And Terrace Deposition In Response To Climate And Tectonics In Southern Taiwan, Dominique M. Shore May 2021

Spatial And Temporal Patterns Of River Incision And Terrace Deposition In Response To Climate And Tectonics In Southern Taiwan, Dominique M. Shore

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

Geologists often look at the Earth’s surface to understand the underlying processes that cause mountain formation. As tectonic forces drive uplift of Earth’s surface, processes of erosion transport sediment to lower elevations. Climate can play a large role in landscape formation as well as increased precipitation, accelerating rates of erosion. Rivers leave markers of landscape evolution through terrace landforms, former river floodplains that are left behind when rivers incise into a valley. To better understand landscape response to uplift, this research investigated the initial linkages between uplift, hillslope erosion (mass wasting) and river incision. At some point, it is thought …


Effects Of The Triassic-Jurassic Central Atlantic Magmatic Event Recorded In Continental Strata In Western Pangea: The Δ13c Record Of Warner Valley & Zion National Park, Dennis Mmasa May 2021

Effects Of The Triassic-Jurassic Central Atlantic Magmatic Event Recorded In Continental Strata In Western Pangea: The Δ13c Record Of Warner Valley & Zion National Park, Dennis Mmasa

Graduate Theses and Dissertations

The Triassic is a period of abrupt climate change bracketed by mass extinctions including one driven by the eruption of the Central Atlantic Magmatic Province (CAMP) in the Late Triassic. The Moenave Formation (MF) of Utah and Arizona is ideal to investigate effects of the CAMP on continental strata distal to the eruptive center. This study focuses on the C-isotopic composition of bulk carbonate C from two localities, Blacks Canyon, Zion National Park, UT and Olsen Canyon within Warner Valley, UT. The data collected was used to document a chemostratigraphic record to compare to globally established records and bulk organic …


Small-Scale Resuspension And Redistribution Of Surface Sediments In The Northeast Gulf Of Mexico, Austin Harris May 2021

Small-Scale Resuspension And Redistribution Of Surface Sediments In The Northeast Gulf Of Mexico, Austin Harris

Master's Theses

Following the release of ~4.9 million barrels of oil into the Gulf of Mexico from the Macondo wellhead, a vast area of the seafloor contained recently deposited marine sediments contaminated by the oil spill. The initial deposition of these contaminated marine sediments was likely not the end of the journey for the particles. Downslope gravitational processes and events of increased current speed in the deep ocean setting can result in recently deposited sediments to resuspend and be moved laterally with the current flow, increasing the area effected by the oil spill. Erosion experiments performed in a closed-loop resuspension flume were …


Structural Re-Orientation Of Magmatic Fabrics And Layering In The Lower Oceanic Crust: Hole Gt1, Wadi Tayin Massif, Samail Ophiolite, Justin Guillot May 2021

Structural Re-Orientation Of Magmatic Fabrics And Layering In The Lower Oceanic Crust: Hole Gt1, Wadi Tayin Massif, Samail Ophiolite, Justin Guillot

Master's Theses

This thesis aims to re-orient borehole images of layered gabbros sampled beneath Hole GT1 in the Wadi Tayin massif of the Oman ophiolite by the Oman Drilling Project to better constrain models of crustal accretion. The gabbro glacier model proposes that crystallized basalt flows down and away from the crystallization site to form the lower crust while the sheeted sill model proposes that basaltic melt crystallizes at multiple levels in the crust through sills. Hole GT1 provides an unprecedented 400 m, 100% recovery, look at the lower oceanic crust. Cores lose their geographic orientation when drilled, requiring use of the …


Effects Of Differences In Cell Wall Biochemistry On The Microbial Decomposition Of Sphagnum (Peat Moss), Alexis Koehl, Christian Lundy, Trevor Hile, Erik Schoonover Apr 2021

Effects Of Differences In Cell Wall Biochemistry On The Microbial Decomposition Of Sphagnum (Peat Moss), Alexis Koehl, Christian Lundy, Trevor Hile, Erik Schoonover

20th Annual Celebration of Undergraduate Research and Creative Activity (2021)

Globally, peatlands store twice as much carbon as there is in the atmosphere as CO2. As average global temperatures continue to rise, the growth or decay of these carbon stores will play an important feedback for future climate change. This study examined the mechanisms behind the rate of decomposition in Sphagnum mosses, specifically the differences in cell wall chemistry between species. We hypothesized that mosses from different microtopographies will differ in rate of decomposition, as previous studies have shown that hummock mosses have higher concentrations of recalcitrant structural carbohydrates in their cell walls compared to hollow mosses. The …


Biis: The Last British Ice Sheet, A Review Of The Most Recent Major Glaciation Of Great Britain And Ireland, Benediktas Gaskevicius Apr 2021

Biis: The Last British Ice Sheet, A Review Of The Most Recent Major Glaciation Of Great Britain And Ireland, Benediktas Gaskevicius

Honors College Theses

The British Irish Ice Sheet was a substantial ice mass covering the British Isles during the most recent glaciation that ended around 11,700 years ago. Oftentimes referred to as the BIIS, it is subdivided into two sections, a western and eastern side that covered Great Britain and Ireland, with the Irish basin in the middle. Some notable areas of study around Great Britain and Ireland include the ’Bizzle’ in Northern England, which was transformed by the effects of the eastern margin of the BIIS, the Carstair Kames in Scotland, a locality known internationally for its esker system, The Minch region …


Dynamic Topography Of The St. Francois Mountains, Joshua Carpenter Apr 2021

Dynamic Topography Of The St. Francois Mountains, Joshua Carpenter

Undergraduate Research Conference at Missouri S&T

The purpose of this research project was to search for evidence of relict topographic surfaces in the St. Francois Mountains that preserve a history of regional and/or global forces. To accomplish this, topographic cross-sections were taken in Google Earth to examine changes in the region's topography with focus towards the following features: sub-horizontal surfaces, knickpoints, and valley floors. Elevation data was then collected and plotted in Excel. This revealed sub-horizontal surfaces between elevations of ~1780-1545 ft; knickpoints between ~1700-900 ft; and valley floors at ~1470-1350 ft. and ~1200-900 ft. The sub-horizontal surfaces are interpreted as relict peneplains preserved during periods …


Equation Of State For Natural Almandine, Spessartine, Pyrope Garnet: Implications For Quartz-In-Garnet Elastic Geobarometry, Suzanne R. Mulligan, Elissaios Stavrou, Stella Chariton, Oliver Tschauner, Ashkan Salamat, Michael Wells, Alexander G. Smith, Thomas D. Hoisch, Vitali Prakapenka Apr 2021

Equation Of State For Natural Almandine, Spessartine, Pyrope Garnet: Implications For Quartz-In-Garnet Elastic Geobarometry, Suzanne R. Mulligan, Elissaios Stavrou, Stella Chariton, Oliver Tschauner, Ashkan Salamat, Michael Wells, Alexander G. Smith, Thomas D. Hoisch, Vitali Prakapenka

Geoscience Faculty Research

The equation of state (EoS) of a natural almandine74spessartine13pyrope10grossular3 garnet of a typical composition found in metamorphic rocks in Earth’s crust was obtained using single crystal synchrotron X-ray diffraction under isothermal room temperature compression. A third-order Birch-Murnaghan EoS was fitted to P-V data and the results are compared with published EoS for iron, manganese, magnesium, and calcium garnet compositional end-members. This comparison reveals that ideal solid solution mixing can reproduce the EoS for this intermediate composition of garnet. Additionally, this new EoS was used to calculate geobarometry on a garnet sample from the same rock, which was collected from the …


201— Diversity, Equity, And Inclusion Within The Department Of Geological Sciences At Suny Geneseo, Maria Leonard Apr 2021

201— Diversity, Equity, And Inclusion Within The Department Of Geological Sciences At Suny Geneseo, Maria Leonard

GREAT Day Posters

The field of Geosciences historically has lacked diversity. This lack of diversity is observed at all levels of higher education—for example, 90% of doctoral degrees are awarded to white people (Wilson, 2016) and only 3.8% of tenured or tenure track positions at the top 100 geoscience departments are held by faculty of color (Bernard & Cooperdock 2018). There are multiple reasons at the heart of this issue including the lack of representation which can fuel stereotype threats and imposter syndromes.

This project aimed to take actions that would help grow the diversity, equity, and accessibility within Geneseo’s GSCI department. This …


357— Dacryoconarids Of The Genundewa And West River Formations, Upper Devonian In Western New York, Emily De Jong Apr 2021

357— Dacryoconarids Of The Genundewa And West River Formations, Upper Devonian In Western New York, Emily De Jong

GREAT Day Posters

The Dacryoconarids, small, thin-walled, and cone-shaped, are an extinct taxon in Class Tentaculitoidea, which is of uncertain affinities. Dacryoconarids were widespread throughout the middle Silurian to the Late Devonian when they went extinct. This study focuses on the lower Upper Devonian Dacryoconarids of the Genundewa and West River formations from western New York State. Samples collected from these formations revealed many smooth shelled Styliolinids, however, no difinitive ribbed Dacryoconarids. Calcite was found to have internally filled in the shell of some Styliolinids, showing how thin the external shell is and raising questions about septa orientations. Due to their global occurrence, …


069— Geomorphic Characteristics Of Canadice Lake, Ny, Watersheds And The Anthropogenic Effects On Watershed Output And Sensitivity, Carla Crampton Apr 2021

069— Geomorphic Characteristics Of Canadice Lake, Ny, Watersheds And The Anthropogenic Effects On Watershed Output And Sensitivity, Carla Crampton

GREAT Day Posters

Land use and size of watershed catchment areas affects the overall health and water quality of Canadice Lake. Methods in ArcGIS Pro were used for high resolution imagery and topography data to analyze the geomorphology of watersheds at Canadice Lake. Watersheds were mapped using ArcGIS Hydrology tools by constructing flow direction and accumulation grids. In each individual watershed, total area of the watershed, area of residential and agricultural land use, and total length of roads was determined to evaluate which watersheds are most sensitive to human impact and which watersheds are likely to contribute the highest flow discharge and sediment …


312— Mineralogical Analysis Of Slag From Iron Production In The Adirondack State Park, Mary Reid, Griffin Rose Apr 2021

312— Mineralogical Analysis Of Slag From Iron Production In The Adirondack State Park, Mary Reid, Griffin Rose

GREAT Day Posters

Slag is a byproduct of iron production formed from the melting of iron-bearing rocks. Iron production in the Adirondacks reached a high in the early to mid 1800s, with many blast furnaces in operation throughout Northern New York. Two sets of samples from different regions in the Adirondacks were collected in the summers of 2019-2020. An unknown sample was taken from the Ausable River at Flume Falls near Wilmington, New York, while other samples were collected from the Mt. Hope iron furnace near Fort Ann, New York. Samples were analyzed through the creation of thin sections and x-ray diffraction. Results …


200— Chemical Analysis Of Slag From Standish, Ny, Maria Leonard, Dori Farthing Apr 2021

200— Chemical Analysis Of Slag From Standish, Ny, Maria Leonard, Dori Farthing

GREAT Day Posters

From 1883 to 1907, magnetite was smelted in Standish, NY. During this time, a large amount of slag, a byproduct of smelting, was created. The slag is now in a pile that covers ~13 acres in the northeastern region of the Adirondacks. The slag at the site has been classified into 6 broad types based on their physical properties. Exemplars of select types were crushed and analyzed by X-ray fluorescence spectroscopy (XRF). Both major elements and trace element data was collected for these samples. The XRF results indicate that all Standish slag is dominated by SiO2, CaO, and Fe2O3(t) regardless …


205— Revisiting The Geologic History Of The Pathfinder Landing Site At Ares Vallis, Mars, Andrew Agent Apr 2021

205— Revisiting The Geologic History Of The Pathfinder Landing Site At Ares Vallis, Mars, Andrew Agent

GREAT Day Posters

Before NASA sent the Pathfinder lander and Sojourner rover to the mouth of Ares Vallis in 1997, they anticipated the discovery of Hesperian-age (3.6 Ga-3.0 Ga) sediments deposited from catastrophic outflows. When pictures came back, the rocks they discovered were large, boulder-size, angular, and were largely inconsistent with transport by large floods. The origin of the deposits at the Pathfinder landing site remains controversial. This study aims to constrain the surface geology of the Pathfinder landing site using new high-resolution imagery and crater statistics. Context Camera (CTX) images along with High-Resolution Imaging Experiment (HiRISE) images were used to map surface …


299— Determining Accuracy Of Xrd From Known Samples, Collin Horrocks Apr 2021

299— Determining Accuracy Of Xrd From Known Samples, Collin Horrocks

GREAT Day Posters

Powdered x-ray diffraction (XRD) is a technique that has the power to identify minerals and the proportion of the minerals in a mixture. A mineral is defined by a repeatable set of planes between atoms that form the crystal lattice. It is this repetition that allows the process of XRD to work. The process is done by taking a powdered sample and placing it into the machine and then shooting x-rays into the sample causing diffraction. From this using Bragg’s Law we can determine the d-spacing which is how an identity is determined for a sample and the intensity of …


344— Wetland Soil, Abigale O'Connor Apr 2021

344— Wetland Soil, Abigale O'Connor

GREAT Day Posters

This project classified soil properties in the vicinity of a wetland in Livonia, NY. Soil cores were collected from the margin of the wetland to observe the changes in the soil profiles across the transition between the wetland and the surrounding forested land. Soil horizons were delineated based on texture and color. Individual horizons were then correlated between the cores to capture spatial changes in thickness and texture. The core descriptions and the correlations were digitized to create an archive of correlations around the wetland for future reference. The distribution of wetland soil textures contributes to better understanding how water …


075— A Test Of The Efficacy Of The Augmented Reality Sandbox To Improve Students' Reading Topographic Map Skills, Megan Jankowiak, Alexandra Ranaudo Apr 2021

075— A Test Of The Efficacy Of The Augmented Reality Sandbox To Improve Students' Reading Topographic Map Skills, Megan Jankowiak, Alexandra Ranaudo

GREAT Day Posters

The augmented reality (AR) sandbox is a teaching tool used to connect two-dimensional (2D) and three-dimensional (3D) map representations through modeling. Our hypothesis is: the AR sandbox is effective at teaching topographic map reading skills by comparing pre vs. post test scores. Student data was processed to analyze the efficiency of using the AR sandbox to increase student ability to read topographic maps. Data consists of student answers on a topographic map reading skills test at the beginning and the end of a Historical Geology college course. Between tests, students used the AR sandbox to complete short exercises during multiple …


024— Optimizing 3d Model Construction Of Rock And Fossil Specimens To Increase Accessibility In An Online Learning Environment, Jaclyn Barreca, Frazer Bourgeois Apr 2021

024— Optimizing 3d Model Construction Of Rock And Fossil Specimens To Increase Accessibility In An Online Learning Environment, Jaclyn Barreca, Frazer Bourgeois

GREAT Day Posters

Three-dimensional modeling of physical objects has become increasingly applicable in the field of geology. A digital collection of samples is important to have in the event of physical loss, as a means to communicate among scientists in reference to a particular sample, to aid in the preservation of original samples, and is particularly relevant in today’s pandemic. Digital models allow for the option of remote learning for students and stops the need for the sharing of physical samples. It also increases accessibility of samples. The problem of generating a 3D model of an object has already been solved; this research …


328— Watershed Analysis Of The Eberswalde Delta (Early Hesperian), Mars, Jason Mueller Apr 2021

328— Watershed Analysis Of The Eberswalde Delta (Early Hesperian), Mars, Jason Mueller

GREAT Day Posters

The Eberswalde Delta is an impressive Martian fluvial-deltaic system. It is fed by an Earth-like dendritic river system that indicates past precipitation. This study is designed to quantify controls on network morphometry and its past extent using Esri ArcMap. Upstream contributing area (km2), elevation (m), depth (m), width (m), W/D ratio, and slope (-m/m), were calculated and graphed by stream order and long profiles. Width/depth increased with distance downstream but fluctuated in the fifth-order channel that was convex with knickpoints. This implied the system was youthful. The fourth-order stream was concave and in a sedimentary sub-basin. This sub-basin may have …


Terrestrial Lidar Scanning And Gaming Engines: Using Unity3d To Visualize High-Resolution Point Clouds From Big Bat Cave, Kentucky, Jeffrey Aaron Baggett Apr 2021

Terrestrial Lidar Scanning And Gaming Engines: Using Unity3d To Visualize High-Resolution Point Clouds From Big Bat Cave, Kentucky, Jeffrey Aaron Baggett

Theses and Dissertations

Terrestrial LiDAR scanning has become a staple of modern speleological research and mapping due to its increasing availability, rapid deployment, and ability to collect large quantities of spatial data in a short period of time. In addition to spatial data, LiDAR scanners’ ability to record reflection intensity is of interest in the geoscience community as a proxy for surface reflectivity and as a means of aiding in visualizations when a lack of lighting prevents the use of photography at a useful scale. In this study, a methodology for rendering a stereoscopic, real-time rendering of a 10 scan, 425-million point portion …


Diversity – Independent Factors Predict Elevated Extinction Rates, Dustin Perriguey, Corinne Myers, Jason Moore, Louis Scuderi Apr 2021

Diversity – Independent Factors Predict Elevated Extinction Rates, Dustin Perriguey, Corinne Myers, Jason Moore, Louis Scuderi

Earth and Planetary Sciences ETDs

Multiple linear regression was used to determine the relationships between diversity-independent factors (i.e., abiotic, climatic) 2, 5, and 10 Myrs-prior to the most elevated Phanerozoic extinctions. We constructed five abiotic variables from Phanerozoic proxy records1–5 to compare to extinction rates: mean temperature, temperature instability, carbon cycle instability, continental weathering rates, and habitat instability. All three models were statistically significant (P < 0.05) and explained > 70% of the variation in Alroy’s6 three-timer generic extinction rates. However, the 2 Myr-prior model explained the most variance in extinction rates and had the most predictive power, based on adjusted and predictive R2 (~ 72% and 41%, respectively). Carbon …


Diversity – Independent Factors Predict Elevated Extinction Rates, Dustin Perriguey Apr 2021

Diversity – Independent Factors Predict Elevated Extinction Rates, Dustin Perriguey

Earth and Planetary Sciences Faculty and Staff Publications

Multiple linear regression was used to determine the relationships between diversity-independent factors (i.e., abiotic, climatic) 2, 5, and 10 Myrs-prior to the most elevated Phanerozoic extinctions. We constructed five abiotic variables from Phanerozoic proxy records1–5 to compare to extinction rates: mean temperature, temperature instability, carbon cycle instability, continental weathering rates, and habitat instability. All three models were statistically significant (P < 0.05) and explained > 70% of the variation in Alroy’s6 three-timer generic extinction rates. However, the 2 Myr-prior model explained the most variance in extinction rates and had the most predictive power, based on adjusted and predictive R2 (~ 72% and 41%, respectively). Carbon …


From Molecules To Mountains: A Multi-Proxy Investigation Into Ancient Climate And Topography Of The Pacific Northwest, Usa, Alex Mclean Apr 2021

From Molecules To Mountains: A Multi-Proxy Investigation Into Ancient Climate And Topography Of The Pacific Northwest, Usa, Alex Mclean

Dissertations and Theses

The modern Cascades are a north-south striking mountain range that intercepts Pacific Ocean-derived moisture resulting in orographic precipitation on the western flank and a relatively arid rain shadow in the lee. Because of the strong coupling between topography and climate and consistent moisture source (Pacific Ocean) throughout the year, the region is ideally situated for paleoclimate studies that utilize the isotopic composition (δ18O and δD) of meteoric water to determine when uplifts occurred. Here, I synthesize the spatial and temporal evolution of stable isotopes in paleowater proxies across the Pacific Northwest during the Cenozoic. New volcanic glass (δD) …


Bedrock To Buildings, Bryer Carlson Apr 2021

Bedrock To Buildings, Bryer Carlson

Michael D. Wilson Symposium

This poster explores Maine's bedrock in relation to the state's infrastructure.


Manganese Oxides In Martian Meteorites Northwest Africa (Nwa) 7034 And 7533, Yang Liu, Woodward W. Fischer, Chi Ma, John R. Beckett, Oliver Tschauner, Yunbin Guan, Usha F. Lingappa, Samuel M. Webb, Vitali B. Prakapenka, Nina L. Lanza, Carl B. Agee Apr 2021

Manganese Oxides In Martian Meteorites Northwest Africa (Nwa) 7034 And 7533, Yang Liu, Woodward W. Fischer, Chi Ma, John R. Beckett, Oliver Tschauner, Yunbin Guan, Usha F. Lingappa, Samuel M. Webb, Vitali B. Prakapenka, Nina L. Lanza, Carl B. Agee

Geoscience Faculty Research

We report the discovery of indigenous Mn-oxides in Martian regolith breccias Northwest Africa (NWA) 7034 and 7533. These Mn-oxides occur in Mn-rich regions as nanocrystals mixed with silicates, FeOOH, and possible phosphates. The Mn-rich regions contain up to 34 wt% Mn and typically display large chemical gradients on the scale of 10–20 μm. The Martian origin of Mn-oxides was established by the presence of Mn-rich glass (4.8–5.6 wt% Mn) in the fusion crust that crosscuts a Mn-oxides-bearing monzonite clast and by the absence of Mn-oxides on the environmentally exposed surfaces (exterior and fractures) of the meteorites. Manganese K-edge X-ray absorption …


Glaciers Of The Olympic Mountains, Washington - The Past And Future 100 Years, Andrew G. Fountain, Christina Gray, Bryce Allen Glenn, Brian Menounos, Justin Pflug, Jon L. Riedel Apr 2021

Glaciers Of The Olympic Mountains, Washington - The Past And Future 100 Years, Andrew G. Fountain, Christina Gray, Bryce Allen Glenn, Brian Menounos, Justin Pflug, Jon L. Riedel

Geology Faculty Publications and Presentations

In 2015, the Olympic Mountains contain 255 glaciers and perennial snowfields totaling 25.34 ± 0.27 km2, half of the area in 1900, and about 0.75 ± 0.19 km3 of ice. Since 1980, glaciers shrank at a rate of -0.59 km2 yr-1 during which 35 glaciers and 16 perennial snowfields disappeared. Area changes of Blue Glacier, the largest glacier in the study region, was a good proxy for glacier change of the entire region. A simple mass balance model of the glacier, based on monthly air temperature and precipitation, correlates with glacier area change. The mass …