Geology Commons^™

Polygonal Sandcracks: Unique Sedimentary Desiccation Structures In Bahamian Ooid Grainstone, Bosiljka Glumac, H. Allen Curran, Sarah A. Motti, Madeline M. Weigner, Sarah Pruss

Geosciences: Faculty Publications

Sandcracks, which are ubiquitous in Holocene eolian and beach backshore carbonate grainstone on Alligator Point, Cat Island, Bahamas, resemble polygonal mudcracks, but formed in ooid sand without muddy matrix. In experiments on Cat Island beach sand, sediment surfaces cracked polygonally in the absence of mud or biofi lms while drying at room temperature due to contraction generated by capillary effects related to surface tension attraction of interstitial water. Gravitational collapse of irregular open pores and repacking of sand grains due to loss of cohesion between particles caused by evaporation of water enhance the cracking process and appearance of polygons by …

Mammalian Fauna From The Fullerton Gravel Pit (Ogallala Group, Late Miocene), Morton County, Kansas, Michael Anthony Calvello

Master's Theses or Doctor of Nursing Practice

The Fullerton Gravel Pit, Morton County, Kansas is one of many sites in western Kansas at which the Ogallala Group crops out. The Ogallala Group was deposited primarily by streams flowing from the Rocky Mountains. Evidence of water transport is observable at the Fullerton Gravel Pit through the presence of allochthonous clasts, cross-bedding, pebble alignment, and fossil breakage and subsequent rounding. Fluvial mechanisms also played an important role in the distribution of fossil material. When the fossils from the Fullerton Gravel Pit are placed in Voorhies Groups, it appears that a majority of them were removed from suspension gradually and …

Techniques To Promote Garry Oak Seedling Growth And Survival In Areas With High Levels Of Herbivory And Competition, David R. Clements, Seth Luginbill, David A. Jordan, Randall Dragt

University Faculty Publications and Creative Works

Though regeneration of Garry oak (Quercus garryana) seedlings within Garry oak ecosystems is important to maintain this threatened habitat, seedling regeneration is often poor. Two independent studies were initiated in the early 2000s to examine questions surrounding Garry oak recruitment: one at the Crow's Nest Ecological Research Area (CNERA) on Salt Spring Island, BC, and another at the Pacific Rim Institute for Environmental Stewardship (PRI) on Whidbey Island, WA. In both areas, Garry oak seedlings were caged and monitored for growth and relative health. Over 8 years at CNERA, growth of caged plants outpaced growth of controls, which was indicative …

Identifying Changes In Climatic Trends And The Fingerprints Of Landuse And Landcover Changes In The High Plains Of The Usa, Denis Mutiibwa

Department of Agricultural and Biological Systems Engineering: Dissertations, Theses, and Student Research

Human activities such as conversion of natural ecosystem to croplands and urban-centers, deforestation and afforestation impact biophysical properties of land surface such as albedo, energy balance, and surface roughness. Alterations in these properties affect the heat and moisture exchanges between the land surface and atmospheric boundary layer. The objectives of this research were; (i) to quantitatively identify the High plains’ regional climate change in temperatures over the period 1895 to 2006, (ii) detect the signatures of anthropogenic forcing of LULC changes on the regional climate change of the High Plains, and (iii) examine the trends in evolving regional latent heat …

New Stable Isotope Record Of Paleoecological Change In The Late Neogene Of The Western Great Plains From Enamel In Large Mammals, Zachary Kita

Department of Earth and Atmospheric Sciences: Dissertations, Theses, and Student Research

An expansion of C₄ grasslands occurred between 6 and 8 million years ago in the Great Plains of North America, as evidenced by a marked shift to more ¹³C-enriched carbon isotope compositions from large fossil mammal tooth enamel and paleosol carbonates. Prior to this expansion, habitats were comprised of exclusively C₃ vegetation. To explore this problem I present a compilation of bulk stable carbon (δ¹³C) and oxygen (δ¹⁸O) isotope values from a variety of large mammals from 6 localities that span from the late Clarendonian to the late Blancan in Nebraska. As expected, …

Full Conference Program With Abstracts, Jason S. Polk, Leslie A. North

International 2011 Conference on Karst Hydrogeology and Ecosystems

No abstract provided.

From Sink To Resurgence: The Buffering Capacity Of A Cave System In The Tongass National Forest, Usa, Chris Groves, Melissa Hendrikson

Earth, Environmental, and Atmospheric Sciences Faculty Publications

The Tongass National Forest of Southeast Alaska, USA, provides a unique environment for monitoring the impact of the cave system on water quality and biological productivity. The accretionary terrane setting of the area has developed into a complex and heterogeneous geologic landscape which includes numerous blocks of limestone with intense karstification. During the Wisconsian glaciation, there were areas of compacted glacial sediments and silts deposited over the bedrock. Muskeg peatlands developed over these poorly drained areas. The dominant plants of the muskeg ecosystem are Sphagnum mosses, whose decomposition leads to highly acidic waters with pH as low as 2.4. These …

Crustal Structure And Evolution Beneath The Colorado Plateau And The Southern Basin And Range Province: Results From Receiver Function And Gravity Studies, Lamuail Bashir, Stephen S. Gao, Kelly H. Liu, Kevin Lee Mickus

Geosciences and Geological and Petroleum Engineering Faculty Research & Creative Works

Over the past several decades, contrasting models have been proposed for the physical and chemical processes responsible for the uplift and long-term stability of the Colorado Plateau (CP) and crustal thinning beneath the Basin and Range Province (BRP) in the southwestern United States. Here we provide new constraints on the models by modeling gravity anomalies and by systematically analyzing over 15,500 P-to-S receiver functions recorded at 72 USArray and other broadband seismic stations on the southwestern CP and the southern BRP. Our results reveal that the BRP is characterized by a thin crust (28.2 ± 0.5 km), a mean V …

The Impact Of Modern Weathering On The Geochemistry Of A Marine Permo-Triassic Boundary Section, Jeremy Christopher Williams

Graduate Masters Theses

The Permian-Triassic Boundary (PTB) marks the end-Permian extinction, the greatest mass extinction recorded in Earth's history. The Attargoo PTB section located in Spiti Valley, Himachal Pradesh, India was situated along the north continental margin of Gondwana-land in the Neo-Tethys Ocean during the end-Permian extinction. In Spiti Valley, PTB sections such as Attargoo are exposed by a thin (~ 2cm) ferruginous layer separating the Permian black shale from Triassic Limestone. Studies that have presented geochemical data to support a theory of the end-Permian extinction lack any interpretation of post-depositional effects on Spiti Valley PTB sections. In order to accurately present a …

Landslide Susceptibility In Tryon State Park, Oregon, Tracy E. Handrich

Anthós

LIDAR and topographic data were used to identify areas of high landslide susceptibility. An arctangent equation was used to calculate slope angle, design criteria of susceptibility and designate zones of high, moderate, and low risk.

Taxonomic Composition, Paleoecology And Biostratigraphy Of Late Cretaceous Diatoms From Devon Island, Nunavut, Canadian High Arctic, Jakub Witkowski, David M. Harwood, Karen Chin

Department of Earth and Atmospheric Sciences: Faculty Publications

Upper Cretaceous sediments of the Kanguk Formation exposed in Eidsbotn and Viks Fiord grabens on Devon Island, Nunavut, Canadian High Arctic, yielded 91 fossil marine diatom species and varieties (including indeterminate taxa), representing 41 genera. Excellent preservation of the assemblages was aided by shallow burial, protection in down­faulted linear grabens, and the presence of abundant volcanic material. Planktonic species and resting spores com­prise nearly 70% of the diatom assemblage, and provided abundant food resources for the Late Cretaceous Arctic eco­system. Deposition of the approximately 225 m-thick stratigraphic sequence was predominantly in a shallow marine neritic setting, with an upward progression …

Secretive Marsh Bird Species Co-Occurrences And Habitat Associations Across The Midwest, Usa, Jason R. Bolenbaugh, Sarah E. Lehnen, David G. Krementz

United States Geological Survey: Staff Publications

Because secretive marsh birds are difficult to detect, population status and habitat use for these birds are not well known. We conducted repeated surveys for secretive marsh birds across 264 sites in the Upper Mississippi River and Great Lakes Joint Venture region to estimate abundance, occupancy, and detection probabilities during the 2008 and 2009 breeding seasons. We identified species groups based on observed species co-occurrences. Two species, least bittern Ixobrychus exilis and American bittern Botaurus lentiginosus, co-occurred with other species less often than expected by chance, and two species groups, rails (Virginia rail Rallus limicola and sora Porzana carolina) and …

Dendrochronological Dating Of The Johnson House, Perry County, Ohio

Historic Structures

Dating historical structures in Perry County, Ohio. The Historical Structures collection consists of reports that are the resoult of dendochronological analysis of timbers from structures in Pennsylvania and Ohio. Contributors: Theisen, Jon; Wiles, Greg

Dendrochronological Dating Of Perry County District Library, Somerset, Ohio

Historic Structures

Dating historical structures in Somerset, Ohio 2011. The Historical Structures collection consists of reports that are the resoult of dendochronological analysis of timbers from structures in Pennsylvania and Ohio. Contributors: Mudd, Anna; Theisen, Jon; Wiles, Greg

Dendrochronological Dating Of The Linnabary House, Worthington, Ohio

Historic Structures

Dating historical structures in Worthington, Ohio 2011. The Historical Structures collection consists of reports that are the result of dendochronological analysis of timbers from structures in Pennsylvania and Ohio. Contributors: Theisen, Jon; Wiles, Greg

Dendrochronological Dating Of The Old Rectory, Worthington, Ohio

Historic Structures

Dating historical structures in Worthington, Ohio. Dating historical structures in Worthington, Ohio. The Historical Structures collection consists of reports that are the result of dendochronological analysis of timbers from structures in Pennsylvania and Ohio. Contributors: Theisen, Jon; Wiles, Greg

The Formation History Of Layered Chondrules In Acfer-139 (Cr2), Matt Downen

Mahurin Honors College Capstone Experience/Thesis Projects

Chondrules are spherical grains made of silicates and metal that represent some of the oldest materials our solar system. Acfer-139 (CR) is a carbonaceous chondrite with large multilayered chondrules. The multilayered chondrules are composed of a silicate core surrounded by alternating layers of silicates and metals. Serial sectioning was used to analyze the sample in three dimensions. EMPA and LA-ICP-MS were used to create elemental maps of Acfer-139 (CR2) and determine the geochemistry of different layers in each thick section cut. XRCMT was used to construct a 3-D model of a large multilayered chondrule named Ch-1 with concentric layers of …

Aerial Reconnaissance Of Stream Terraces And Landslides Within Bitterwater Creek Watershed In Kern County, California, Zachary Smith

Natural Resources Management and Environmental Sciences

No abstract provided.

Rapid Wetland Expansion During European Settlement And Its Implication For Marsh Survival Under Modern Sediment Delivery Rates, Matthew L. Kirwan, A. Brad Murray, Jeffrey P. Donnelly, D. Reide Corbett

United States Geological Survey: Staff Publications

Fluctuations in sea-level rise rates are thought to dominate the formation and evolution of coastal wetlands. Here we demonstrate a contrasting scenario in which land-use–related changes in sediment delivery rates drive the formation of expansive marshland, and vegetation feedbacks maintain their morphology despite recent sediment supply reduction. Stratigraphic analysis and radiocarbon dating in the Plum Island Estuary (Massachusetts, United States) suggest that salt marshes expanded rapidly during the eighteenth and nineteenth centuries due to increased rates of sediment delivery following deforestation associated with European settlement. Numerical modeling coupled with the stratigraphic observations suggests that existing marshland could survive, but not …

Evapotranspiration In The Riparian Zone Of The Lower Boise River With Implications For Groundwater Flow, Brady Allen Johnson

Boise State University Theses and Dissertations

Riparian zones in semi-arid regions often exhibit high rates of evapotranspiration (ET) in spite of low soil moisture content due to vegetation that is able to withdraw water from shallow aquifers. This work better defines the relationship between ET and the saturated zone by comparing the observed water table drawdown to analytically modeled drawdown in fully penetrating wells of an unconfined aquifer in response to daily ET flux. ET at the Boise Hydrogeophysical Research Site or BHRS (a riparian zone in a temperate, semi arid environment) is calculated following the approach of Batra et al. (2006) but uses site …

Memorial To Charles Alexander Baskerville (1928–2009), Allen W. Hatheway, Ajitkumar Shah, Joseph J. Lifrieri, Nazrul I. Khandaker, Stanley Schleifer

Publications and Research

Charles Alexander Baskerville captured our imagination, as a senior colleague in the practice of engineering geology in New York City. “Charlie” held the seat of master Big Apple Geologist during his matured career. He was the source, he knew the possibilities, he was aware of the pitfalls of this most geologically complex of American cities. His final work was his greatest reach—the four bedrock geologic quadrangles of the city. Baskerville mapped New York City for more than fifty years. He was sought and given access to sites of bedrock and bedrock/ overburden interface on the various capitol construction projects undertaken …

Spatial Analysis Of A Bioterrorist Attack On Four Major United States Cities Using An Aerosolized Hemorrhagic Fever Virus, Kathryn Prinslow

Master's Theses or Doctor of Nursing Practice

Before the attack on September 11,2001, the United States was very vulnerable to a biological attack. Since then, those responsible for the security of the United States Homeland Security have become more aware of the country's vulnerability. Biological agents have the potential to give small groups of people unprecedented power to terrorize, as indicate by the "Amerithrax" attack in 2001, and of all of these agents, none have more potential for destruction than Ebola Hemorrhagic Fever (EHF). This research uses one of the deadliest viruses that have not been eradicated to identify the number of fatalities in an outbreak affecting …

Geoenabling A Rural Community Through Web Gis: A Case Study Of The City Of Hays, Ellis County Kansas, Eamonn W. Coveney

Master's Theses or Doctor of Nursing Practice

The objective of this study was to describe the internet GIS implementation in the City of Hays and Ellis County, Kansas, then compare it to examples of implementation from other similar communities. Geospatial resources were consolidated from both agencies and used to develop two web mapping applications for employee and public access. Both mapping applications were developed on the ArcGIS Server platform using the .NET Web Application Developer Framework. In addition, a HTML website was developed to accommodate common data requests and an online map repository. The implementation approach of the City of Hays and Ellis County is similar to …

The Mammals And Paleoindian Artifact From The Feaster Sand Pit, Late Pleistocene (Wisconsin)-Early Holocene, Of Cowley County (Southeastern), Kansas, Miranda L. Lucas

Master's Theses or Doctor of Nursing Practice

Over 100 fossil remains of late Pleistocene (Wisconsin)-early Holocene mammals, including one modified by Paleoindians into an arrow shaft straightener were recovered from the Feaster sand pit in the southwestern part of Cowley County, Kansas. Taxa identified to species include Procyon lotor (Linnaeus), Mammut Americanum (Kerr), Mammuthus columbi (Falconer), Mammuthus jeffersonii (Osborn), Equus scotti (Gidley), Equus conversidens (Owen), Camelops hesternus (Leidy), Antilocapra americana (Ord), and Bison antiquus (Ledy). The Feaster sand pit is thought to be late Pleistocene (Wisconsin) to early Holocene in age due to the high co-occurrence of mammals that are similar to the taxa of known late …

An Allosaurus From The Morrison Formation (Late Jurassic) Of Converse County, Wyoming, Dennis D. Roth

Master's Theses or Doctor of Nursing Practice

I describe a partial skeleton of a theropod from the Later Jurassic Morrison Formation of Converse County, Wyoming. Collected material included 17 vertebrae, three ribs, two associated left metatarsals and an incomplete ilium of an Allosaurus in a gray silty-mudstone containing conchostraca. Several vertebrae are deformed with transverse processes broken and pressed against the neural spine, or twisted transverse processes from lateral or dorso-venteral compression. The material has evidence of erosion prior to deposition, as well as during postfossilization. I propose the deformation of the vertebrae is due to a demineralization of the bones. The flattened surfaces appear to have …

Mesozoic Burial, Mesozoic And Cenozoic Exhumation Of The Funeral Mountains Core Complex, Death Valley, Southeastern California, Mengesha Assefa Beyene

UNLV Theses, Dissertations, Professional Papers, and Capstones

The Funeral Mountains of Death Valley National Park, CA, provide an opportunity to date metamorphism resulting from crustal shortening and subsequent episodic extensional events in the Sevier hinterland. It was not clear whether crustal shortening and thus peak temperature metamorphism in the hinterland of the Sevier-Laramide orogenic wedge have occurred whether in Late Jurassic, Early Cretaceous , Late Cretaceous or somewhere between. Particularly ambiguous is the timing of crustal shortening in the deep levels of the hinterland of the Sevier belt, now manifest in the metamorphic core complexes, and how and when these middle-to-lower crustal rocks were exhumed. A 6-point …

Molecular Organic Geochemistry Of The Oil And Source Rocks In Railroad Valley, Eastern Great Basin, Nevada, United States, Laode Ahdyar

UNLV Theses, Dissertations, Professional Papers, and Capstones

A comprehensive geochemical study of oils from Railroad Valley, Nevada and two candidate source rock intervals from the nearby Egan Range, was conducted in order to establish oil-oil and oil-source rock correlations. Analyses consisted of total organic carbon, Rock-Eval pyrolysis, and vitrinite reflectance for source rock samples, as well as biomarker, diamondoids, and stable carbon isotope analyses on source rock extracts and oil samples.

Total organic carbon analyses showed high organic content in the Mississippian Chainman Shale. However, outcrop samples of the Paleogene Sheep Pass Formation Member B are organically lean. Strata in both of these units are immature to …

Vertebrate Taxonomic Composition, Species Diversity, And Paleoecology Of Two Pliocene Mid-Latitude, Inland-Basin Fossil Assemblages: Panaca Local Fauna (Lincoln County, Nevada) And Hagerman Local Fauna (Twin Falls County, Idaho), Vicki Lynn Meyers

UNLV Theses, Dissertations, Professional Papers, and Capstones

I studied the sedimentology, species diversity, relative abundance, paleoenvironment, and paleoecology of the vertebrate fauna of the early Pliocene (Blancan Land Mammal Age) Panaca Formation of southeastern Nevada, and I compared these data with the slightly younger Hagerman fauna of south-central Idaho. The purpose of this study is to characterize the paleoecology and species diversity of mid-latitude inland basins during the Blancan Land Mammal Age, a time of climate change and immigrating taxa from Asia and South America. This study involved surface collecting and screenwashing of the Panaca Formation sediment in Meadow Valley, as well as a compilation of data …

Geochemical Controls On Mercury Methylation In Backwaters Of A Gulf Coastal Plain River System, Implications For Water Column Processes, Liam N. Schenk

Graduate Theses and Dissertations

The abundance and distribution of mercury and methyl mercury were investigated at three sites in the lower Ouachita River in the summer of 2010 in an effort to provide the first characterization of the extent of mercury contamination in this river system, and to investigate the potential for mercury methylation in the water column of backwaters off of the main channel. Results showed that filtered methyl mercury was positively correlated to dissolved organic carbon (r2=0.76) for water samples taken from the bottom 1 ft of the water column at three sites, suggesting the importance of dissolved organic carbon in mercury …

Pleistocene Climate In Alaska From Stable Isotopes In An Ice Wedge, Corinne Y. Griffing

UNLV Theses, Dissertations, Professional Papers, and Capstones

The CRREL permafrost tunnel offers a unique opportunity to sample ice wedges in a climate-controlled environment, penetrating frozen silts which host massive ground ice that may record Dansgaard-Oeschger (D-O) and Heinrich Events. Ice wedges in the tunnel have been dated to approximately 36-22 ka (Hamilton et al., 1988), allowing the paleoclimate of the region to be reconstructed during MIS 3, when D-O and Heinrich events were documented in various other records. These climate cycles are rapid climate oscillations that have been recognized in records from the Arctic and subarctic, and suggest that climate can rapidly shift by 10°C over millennial …