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Articles 511 - 540 of 1632
Full-Text Articles in Earth Sciences
Landmark Analysis Of Musteloid Carnassials Applied To Taxonomic Identification And Examination Of Sexual Dimorphism And Regional Morphotypes, Joel Alvin Christine
Landmark Analysis Of Musteloid Carnassials Applied To Taxonomic Identification And Examination Of Sexual Dimorphism And Regional Morphotypes, Joel Alvin Christine
Electronic Theses and Dissertations
Guy Wilson Cave (GWC) in Sullivan County, Tennessee holds many late Pleistocene mammal fossils. Based on visual morphology, several partial mandibles with lower carnassial from GWC appeared to be musteloids. Geometric morphometrics has been successfully used to identify fragmentary fossils, so a landmark based, 2 dimensional technique was applied to identify the GWC musteloids using the lower carnassial. Digital images of several GWC fossils and of extant reference musteloids were combined using morphometric programs tpsDIG1, tpsUtil, and tpsSuper. Statistical data analysis was performed in PASW Statistics. Results successfully separated Mephitis mephitis (striped skunk) from M. macroura (hooded skunk) and Martes …
North Central Region Soil Survey Conference Field Tour
North Central Region Soil Survey Conference Field Tour
Conservation and Survey Division: Faculty and Staff Publications
No abstract provided.
4th International Union Of Soil Sciences Soil Classification Conference Field Tour Guidebook
4th International Union Of Soil Sciences Soil Classification Conference Field Tour Guidebook
Conservation and Survey Division: Faculty and Staff Publications
No abstract provided.
Mary Anning Of Lyme Regis: 19th Century Pioneer In British Palaeontology, Larry E. Davis
Mary Anning Of Lyme Regis: 19th Century Pioneer In British Palaeontology, Larry E. Davis
Headwaters
No abstract provided.
Sedimentology And Geochronology Of Holocene Paleochannel Features In The Lower Ohio River Valley, Indiana, Kathryn G. De Rego, C. Russell Stafford, Mark Cantin
Sedimentology And Geochronology Of Holocene Paleochannel Features In The Lower Ohio River Valley, Indiana, Kathryn G. De Rego, C. Russell Stafford, Mark Cantin
Symposium 2012
Rivers condition human settlement strategy by determining both the location of aquatic resources and the stability of the landscape. Therefore, understanding where the river was and how quickly it migrated in the past aids in predicting buried site potential. This study investigates the sedimentology and geochronology of paleochannel deposits along the Lower Ohio River floodplain. A series of low, wide swales are prominent features in a series of bottoms in a ~40 km section of the river valley downstream from the Falls of the Ohio. Previous studies in Knob Creek Bottom indicate that one of these paleochannel swales was active …
The Use Of Diatoms To Infer Environmental Change Of The Lower White River, Southeastern Arkansas, Ruchi Bhattacharya
The Use Of Diatoms To Infer Environmental Change Of The Lower White River, Southeastern Arkansas, Ruchi Bhattacharya
Graduate Theses and Dissertations
This dissertation describes the limnology of the lower White River oxbow lakes in southeast Arkansas, inundated by the major 2008 spring flood. The flood water and sediment deposited in oxbow lakes were analyzed for water chemistry, sediment geochemistry and diatom assemblages and used as an analogue for past floods. The 2008 spring flood inundated and homogenized the entire floodplain; also represented by the predominantly planktonic diatom assemblage suggesting riverine input. Indicator species for eutrophication were also recorded consistent with the high nutrient content in the lakes. However, the variance in the surface diatom assemblage was best explained by the lake …
From The Foreland To The Hinterland: Taphonomy Across The Cretaceous To Paleogene Sevier Retroarc Region Of Nevada, Joshua William Bonde
From The Foreland To The Hinterland: Taphonomy Across The Cretaceous To Paleogene Sevier Retroarc Region Of Nevada, Joshua William Bonde
UNLV Theses, Dissertations, Professional Papers, and Capstones
Until 2004 very little paleobiology, let alone paleoecology, had been studied within exposures of the Sevier retro-arc foreland and hinterland, in the state of Nevada. This is due largely to poor and spotty exposure. This study focuses on taphonomic processes within three stratigraphic intervals in the foreland and hinterland of the Sevier retro-arc region, and what these taphonomic indicators reveal about the geography of the hinterland.
First, the Willow Tank Formation of southern Nevada was deposited in the foredeep of the Sevier retroarc foreland basin. This unit represents a multi-channel, aggradational, fluvial system that drained the Sevier highlands to the …
Paleobiological Assessment Of Controls Underlying Long-Term Diversity Dynamics, Andrés L. Cárdenas
Paleobiological Assessment Of Controls Underlying Long-Term Diversity Dynamics, Andrés L. Cárdenas
USF Tampa Graduate Theses and Dissertations
Deciphering the factors underlying both long-term patterns of diversity and taxonomic turnover rates (i.e., extinction, and origination) has been one of Paleobiology's major foci for the past three decades. The importance of documenting these components is that they will expand our ability to interpret and model the evolutionary processes underlying those trends, highlight the evolutionary impact of historical events, and contribute to the formulation of robust predictions about the future of global diversity in response to the current anthropologically driven environmental changes. Accordingly, the first part of this study examines the possible occurrence of global marine evolutionary environmental controls into …
Plankton Evolution Driven By Paleoceanographic Change: Prediscosphaera From The Mid-Cretaceous In The Western North Atlantic, Kristen L. Mitchell
Plankton Evolution Driven By Paleoceanographic Change: Prediscosphaera From The Mid-Cretaceous In The Western North Atlantic, Kristen L. Mitchell
Department of Earth and Atmospheric Sciences: Dissertations, Theses, and Student Research
Well-preserved nannofossil assemblages in late Albian and Cenomanian hemipelagic sections from Ocean Drilling Program (ODP) Leg 171B preserve a record of the early history and adaptive radiation of the calcareous nannofossil genus Prediscosphaera. There was a significant rise in the abundance of the genus (from an average of 2% in the early late Albian to about 6% in the latest Albian and Cenomanian. This rise, and other shorter term pulses of increased generic abundance, corresponds to black shale deposition episodes. Twelve distinct morphotypes that were derived from the long-ranging Prediscosphera columnata and Prediscosphaera spinosa, are recognized and differentiated …
Algal Stromatolites In The Willow River Member Of The Lower Ordovician Shakopee Formation Near Chatfield, Minnesota, Usa, Sophia L. May, Larry E. Davis, David G. Brown
Algal Stromatolites In The Willow River Member Of The Lower Ordovician Shakopee Formation Near Chatfield, Minnesota, Usa, Sophia L. May, Larry E. Davis, David G. Brown
The Compass: Earth Science Journal of Sigma Gamma Epsilon
No abstract provided.
Mary Anning: Princess Of Palaeontology And Geological Lioness, Larry E. Davis
Mary Anning: Princess Of Palaeontology And Geological Lioness, Larry E. Davis
The Compass: Earth Science Journal of Sigma Gamma Epsilon
On April 17, 2005, delegates at the 39th Biennial Convention of the Society of Sigma Gamma Epsilon passed a motion to include Mary Anning as one of the guiding pillars of geology in the Ritual of the Society. Mary Anning, of Lyme Regis, England, was a 19th century collector of fossils who made significant contributions to the growth of British palaeontology. Among her finds was one of the most complete specimens of Ichthyosaurs found in Britain, as well as the discovery of the first British Plesiosaurus and Dimorphodon (pterosaur). Mary Anning also discovered the true nature of coprolites. …
Ancient Cataclysmic Floods In The Pacific Northwest: Ancestors To The Missoula Floods, Erica Medley
Ancient Cataclysmic Floods In The Pacific Northwest: Ancestors To The Missoula Floods, Erica Medley
Dissertations and Theses
Ancient Cataclysmic Floods were the Ice Age Floods that left erosional and depositional features and preceded the Missoula Floods (15-18,000 ka) in the Pacific Northwest of the United States (Allen et al., 2009). All previously studied ancient sites were visited (14) and new sites (11) were found; four Missoula Flood quarries were also visited; a total of 29 sites were studied in this thesis. The use of calcrete paleosols to provide relative age dates for flood deposits was analyzed in this thesis. Missoula Flood gravel pits were sampled in order to examine the degree of calcrete development in flood deposits …
Three-Dimensional Hydrostratigraphy Of The Platte River Valley Near Ashland, Nebraska: Results From Helicopter Electromagnetic (Hem) Mapping In The Eastern Nebraska Water Resources Assessment (Enwra), P. R. Hanson, Jesse T. Korus, Dana Divine
Three-Dimensional Hydrostratigraphy Of The Platte River Valley Near Ashland, Nebraska: Results From Helicopter Electromagnetic (Hem) Mapping In The Eastern Nebraska Water Resources Assessment (Enwra), P. R. Hanson, Jesse T. Korus, Dana Divine
Conservation and Survey Division: Faculty and Staff Publications
No abstract provided.
Three-Dimensional Hydrostratigraphy Of The Sprague, Nebraska Area: Results From Helicopter Electromagnetic (Hem) Mapping For The Eastern Nebraska Water Resources Assessment (Enwra), Dana Divine, Jesse T. Korus
Three-Dimensional Hydrostratigraphy Of The Sprague, Nebraska Area: Results From Helicopter Electromagnetic (Hem) Mapping For The Eastern Nebraska Water Resources Assessment (Enwra), Dana Divine, Jesse T. Korus
Conservation and Survey Division: Faculty and Staff Publications
No abstract provided.
A Large Cervidae Holocene Accumulation In Eastern Brazil: An Example Of Extreme Taphonomical Control In A Cave Environment, Alex Hubbe, Augusto S. Auler
A Large Cervidae Holocene Accumulation In Eastern Brazil: An Example Of Extreme Taphonomical Control In A Cave Environment, Alex Hubbe, Augusto S. Auler
International Journal of Speleology
A remarkable cervid bone accumulation occurs at a single passage (named Cervid Passage; CP) at Lapa Nova, a maze cave in eastern Brazil. CP lies away from cave entrances, is a typical pitfall passage and contains bone remains of at least 121 cervids, besides few bats, peccaries and rodents remains. There is no evidence of water (or sediment) flow at the site and in general bones lack post depositional alterations and display anatomical proximity, suggesting that the majority of the remains found inside CP (mainly cervids) are due to animals that after entering the cave got trapped in the site. …
Varying Sediment Sources (Hudson Strait, Cumberland Sound, Baffin Bay) To The Nw Labrador Sea Slope Between And During Heinrich Events 0 To 4, J. T. Andrews, Donald C. Barber, A. E. Jennings, D. D. Erbel, B. Maclean, M. E. Kirby, J. S. Stoner
Varying Sediment Sources (Hudson Strait, Cumberland Sound, Baffin Bay) To The Nw Labrador Sea Slope Between And During Heinrich Events 0 To 4, J. T. Andrews, Donald C. Barber, A. E. Jennings, D. D. Erbel, B. Maclean, M. E. Kirby, J. S. Stoner
Geology Faculty Research and Scholarship
Core HU97048-007PC was recovered from the continental Labrador Sea slope at a water depth of 945m, 250km seaward from the mouth of Cumberland Sound, and 400km north of Hudson Strait. Cumberland Sound is a structural trough partly floored by Cretaceous mudstones and Paleozoic carbonates. The record extends from ~ 10 to 58k cal a BP. On-board logging revealed a complex series of lithofacies, including buff-colored detrital carbonate-rich sediments [Heinrich (H)-events] frequently bracketed by black facies. We investigate the provenance of these facies using quantitative X-ray diffraction on drill-core samples from Paleozoic and Cretaceous bedrock from the SE Baffin Island Shelf, …
An Elusive Carnivore Skeleton Discovered At The Ashfall Fossil Beds, Rick E. Otto
An Elusive Carnivore Skeleton Discovered At The Ashfall Fossil Beds, Rick E. Otto
University of Nebraska State Museum: Programs Information
An articulated skeleton of the fossil dog Cynarctus has been revealed at the Ashfall Fossil Beds. Cynarctus fits into the subfamily of Canids known as Borophaginae, an extinct group - some of which are referred to as “bone-crushers”. Cynarctus and a few of its allies appear to have had an omnivorous diet; with dentition similar to Procyonthe modern raccoon. The skeleton, as well as a complete skull and mandibles of a separate individual also recovered from the volcanic ash bed, are the well-preserved remains of a species otherwise poorly represented in the fossil record.
Effectiveness Of Four Water-Bearing Zones Of The Glacierized Basin In Meltwater Runoff Modeling, Umesh K. Haritashya
Effectiveness Of Four Water-Bearing Zones Of The Glacierized Basin In Meltwater Runoff Modeling, Umesh K. Haritashya
Department of Earth, Environment and Sustainability Faculty Publications
Meltwater runoff modeling from glacierized basins needs several input data, including total meltwater contributing area. This study utilizes optical remote sensing data to assess glacierized basins in the central Himalayas where snow and glaciers contribute substantially to the water resources. Result shows that there are four main water-bearing zones in the basin: (a) dry snow, (b) wet snow, (c) exposed glacial ice, and (d) debris-covered glacial ice, and it is possible to differentiate and map these zones and their spatio-temporal variations from satellite sensor data. These zones can then be incorporated in meltwater runoff modeling as separate entities because they …
Guidebook To The Geology Of The Platte River Valley Between Duncan And Schuyler, Nebraska, P.R. Hanson, Robert Matthew Joeckel, Aaron R. Young, Dana Divine, Jesse T. Korus Dr.
Guidebook To The Geology Of The Platte River Valley Between Duncan And Schuyler, Nebraska, P.R. Hanson, Robert Matthew Joeckel, Aaron R. Young, Dana Divine, Jesse T. Korus Dr.
Conservation and Survey Division: Faculty and Staff Publications
The Platte River is considered to be a classic example of a braided stream, that is, a comparatively shallow stream with a high width:depth ratio.
Calcareous Nannofossil Assemblage Changes Across The Paleocene–Eocene Thermal Maximum: Evidence From A Shelf Setting, Jean M. Self-Trail, David S. Powars, David K. Watkins, Gregory A. Wandless
Calcareous Nannofossil Assemblage Changes Across The Paleocene–Eocene Thermal Maximum: Evidence From A Shelf Setting, Jean M. Self-Trail, David S. Powars, David K. Watkins, Gregory A. Wandless
Department of Earth and Atmospheric Sciences: Faculty Publications
Biotic response of calcareous nannoplankton to abrupt warming across the Paleocene/Eocene boundary reflects a primary response to climatically induced parameters including increased continental runoff of freshwater, global acidification of seawater, high sedimentation rates, and calcareous nannoplankton assemblage turnover. We identify ecophenotypic nannofossil species adapted to low pH conditions (Discoaster anartios, D. araneus, Rhomboaster spp.), excursion taxa adapted to the extremely warm climatic conditions (Bomolithus supremus and Coccolithus bownii), three species of the genus Toweius (T. serotinus, T. callosus, T. occultatus) adapted to warm, rather than cool, water conditions, opportunists adapted to high productivity conditions (Coronocyclus bramlettei, …
Nebraska Statewide Groundwater-Level Monitoring Report 2011, Jesse T. Korus Dr., Mark E. Burbach, Leslie M. Howard
Nebraska Statewide Groundwater-Level Monitoring Report 2011, Jesse T. Korus Dr., Mark E. Burbach, Leslie M. Howard
Conservation and Survey Division: Faculty and Staff Publications
No abstract provided.
Three Geologic Cross Sections Across Portions Of Eastern Nebraska Showing Quaternary Lithologic Units And Stratigraphy Of Uppermost Bedrock, Jesse T. Korus, Dana Divine, P. R. Hanson, J. S. Dillon
Three Geologic Cross Sections Across Portions Of Eastern Nebraska Showing Quaternary Lithologic Units And Stratigraphy Of Uppermost Bedrock, Jesse T. Korus, Dana Divine, P. R. Hanson, J. S. Dillon
Conservation and Survey Division: Faculty and Staff Publications
No abstract provided.
Nebraska Statewide Groundwater-Level Monitoring Report 2012, A. R. Young, M. E. Burbach, J. T. Korus, L. M. Howard
Nebraska Statewide Groundwater-Level Monitoring Report 2012, A. R. Young, M. E. Burbach, J. T. Korus, L. M. Howard
Conservation and Survey Division: Faculty and Staff Publications
No abstract provided.
Impact Of Abrupt Deglacial Climate Change On Tropical Atlantic Subsurface Temperatures, Matthew W. Schmidt, Ping Chang, Jennifer E. Hertzberg, Theodore R. Them Ii, Link Li, Bette L. Otto-Bliesner
Impact Of Abrupt Deglacial Climate Change On Tropical Atlantic Subsurface Temperatures, Matthew W. Schmidt, Ping Chang, Jennifer E. Hertzberg, Theodore R. Them Ii, Link Li, Bette L. Otto-Bliesner
OES Faculty Publications
Both instrumental data analyses and coupled ocean-atmosphere models indicate that Atlantic meridional overturning circulation (AMOC) variability is tightly linked to abrupt tropical North Atlantic (TNA) climate change through both atmospheric and oceanic processes. Although a slowdown of AMOC results in an atmospheric-induced surface cooling in the entire TNA, the subsurface experiences an even larger warming because of rapid reorganizations of ocean circulation patterns at intermediate water depths. Here, we reconstruct high-resolution temperature records using oxygen isotope values and Mg/Ca ratios in both surface- and sub-thermocline-dwelling planktonic foraminifera from a sediment core located in the TNA over the last 22 ky. …
Deglacial Variability Of Antarctic Intermediate Water Penetration Into The North Atlantic From Authigenic Neodymium Isotope Ratios, Ruifang C. Xie, Franco Marcantonio, Matthew W. Schmidt
Deglacial Variability Of Antarctic Intermediate Water Penetration Into The North Atlantic From Authigenic Neodymium Isotope Ratios, Ruifang C. Xie, Franco Marcantonio, Matthew W. Schmidt
OES Faculty Publications
Understanding intermediate water circulation across the last deglacial is critical in assessing the role of oceanic heat transport associated with Atlantic Meridional Overturning Circulation variability across abrupt climate events. However, the links between intermediate water circulation and abrupt climate events such as the Younger Dryas (YD) and Heinrich Event 1 (H1) are still poorly constrained. Here, we reconstruct changes in Antarctic Intermediate Water (AAIW) circulation in the subtropical North Atlantic over the past 25 kyr by measuring authigenic neodymium isotope ratios in sediments from two sites in the Florida Straits. Our authigenic Nd isotope records suggest that there was little …
Solar Forcing Of Florida Straits Surface Salinity During The Early Holocene, Matthew W. Schmidt, William A. Weinlein, Franco Marcantonio, Jean Lynch-Stieglitz
Solar Forcing Of Florida Straits Surface Salinity During The Early Holocene, Matthew W. Schmidt, William A. Weinlein, Franco Marcantonio, Jean Lynch-Stieglitz
OES Faculty Publications
Previous studies showed that sea surface salinity (SSS) in the Florida Straits as well as Florida Current transport covaried with changes in North Atlantic climate over the past two millennia. However, little is known about earlier Holocene hydrographic variability in the Florida Straits. Here, we combine Mg/Ca-paleothermometry and stable oxygen isotope measurements on the planktonic foraminifera Globigerinoides ruber (white variety) from Florida Straits sediment core KNR166-2 JPC 51 (24° 24.70' N, 83° 13.14' W, 198 m deep) to reconstruct a high-resolution (~25 yr/sample) early to mid Holocene record of sea surface temperature and δ18OSW)(a …
Three-Dimensionally Preserved Integument Reveals Hydrodynamic Adaptations In The Extinct Marine Lizard Ectenosaurus (Reptilia, Mosasauridae), Johan Lindgren, Michael J. Everhart, Michael W. Caldwell
Three-Dimensionally Preserved Integument Reveals Hydrodynamic Adaptations In The Extinct Marine Lizard Ectenosaurus (Reptilia, Mosasauridae), Johan Lindgren, Michael J. Everhart, Michael W. Caldwell
Sternberg Museum of Natural History Faculty Publications
The physical properties of water and the environment it presents to its inhabitants provide stringent constraints and selection pressures affecting aquatic adaptation and evolution. Mosasaurs (a group of secondarily aquatic reptiles that occupied a broad array of predatory niches in the Cretaceous marine ecosystems about 98-65 million years ago) have traditionally been considered as anguilliform locomotors capable only of generating short bursts of speed during brief ambush pursuits. Here we report on an exceptionally preserved, long-snouted mosasaur (Ectenosaurus clidastoides) from the Santonian (Upper Cretaceous) part of the Smoky Hill Chalk Member of the Niobrara Formation in western Kansas, USA, that …
Extreme Variation In The Sagittal Crest Of Tapirus Polkensis (Mammalia Perissodactyla) At The Gray Fossil Site Northeastern Tn., Aaron Randall Abernethy
Extreme Variation In The Sagittal Crest Of Tapirus Polkensis (Mammalia Perissodactyla) At The Gray Fossil Site Northeastern Tn., Aaron Randall Abernethy
Electronic Theses and Dissertations
The preservation and quantity of fossil tapirs (Tapirus polkensis) from the Gray Fossil Site in northeastern Tennessee provides a unique opportunity for comparison and analysis of skeletal characters. Intraspecifically, modern tapirs show little to no variation in the morphology of the sagittal crest. However, several different morphologies exist within the sample at Gray. No osteological evidence of sexual dimorphism exists for tapirs, and no correlation between crest shape and sex was observed. Several juveniles display well defined crests, while some adults have only minor thickening of the temporal ridges; therefore, no distinct correlation between age and crest state …
The Application Of Biostratigraphy And Paleoecology At Southern Ocean Drill Sites To Resolve Early To Middle Miocene Paleoclimatic Events, Ryan Farmer
Department of Earth and Atmospheric Sciences: Dissertations, Theses, and Student Research
The diatom biostratigraphy and paleoceanography of Ocean Drilling Program (ODP) Site 744 on the Southern Kerguelen Plateau, southern Indian Ocean are documented for the early to middle Miocene to improve chronostratigraphic age control for the Southern Ocean and Antarctic region. Paleoenvironmental fluctuations in the Southern Ocean are inferred from changes in fossil diatom abundance, preservation, and assemblage composition. A robust, new age model for Holes 744A and 744B is constructed using Constrained Optimization (CONOP) model ages for diatom biostratigraphic datum levels and new magnetic polarity data, which enables assessment of a nearly continuous record of paleoenvironmental change from ~20.25 to …
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, …