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

Geology Commons™

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

29,938 Full-Text Articles 16,127 Authors 6,782,393 Downloads 178 Institutions

All Articles in Geology

Faceted Search

29,938 full-text articles. Page 1230 of 1248.

From Sink To Resurgence: The Buffering Capacity Of A Cave System In The Tongass National Forest, Usa, Chris Groves, Melissa Hendrikson 2011 Western Kentucky University

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 2011 Missouri University of Science and Technology

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 2011 University of Massachusetts Boston

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 2011 Portland State University

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 2011 University of Warsaw, Poland

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 2011 University of Arkansas, Fayetteville

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, 2011 The College of Wooster

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, 2011 The College of Wooster

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, 2011 The College of Wooster

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, 2011 The College of Wooster

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 2011 Western Kentucky University

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 2011 California Polytechnic State University, San Luis Obispo

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 2011 U.S. Geological Survey, Charlottesville

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 2011 Boise State University

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 2011 University of Missouri

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 2011 Fort Hays State University

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 2011 Fort Hays State University

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 2011 Fort Hays State University

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 2011 Fort Hays State University

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 2011 University of Nevada, Las Vegas

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 …


Digital Commons powered by bepress