Paleontology Commons^™

A Centennial Record Of Paleosalinity Change In The Tidal Reaches Of The Potomac And Rappahannock Rivers, Tributaries To Chesapeake Bay, Neil E. Tibert, Lindsay J. Walker, William P. Patterson, J. Bradford Hubeny, Emma Jones, Olivia R. Cooper

Virginia Journal of Science

Gravity and push cores from the Potomac and Rappahannock Rivers (Virginia Tidewater) were collected from central and proximal estuarine zones with known seasonal salinity stratification. The lowermost microfossil associations in the cores comprise alternating ostracode populations of Cyprideis salebrosa and Cytheromorpha. This microfossil association gives way to an oligohaline association dominated by the freshwater ostracode Darwinula stevensoni. Stable oxygen isotope values (δ¹⁸O) of Rapphannock Cyprideis salebrosa are highly variable ranging between -6.6 to -3.2‰ VPDB. δ¹⁸O values for Potomac Cytheromorpha fuscata range from -8.2 to -3.2‰ VPDB. Positive excursions in δ¹⁸O values …

Nebraska's Wetlands: Their Wildlife And Ecology, Paul A. Johnsgard

Conservation and Survey Division: Faculty and Staff Publications

1 An Overview of Nebraska's Wetlands

2 The Missouri Valley • Natural History Profiles of Some Missouri Valley Wetland Species • The Missouri Valley Wetlands

3 The Niobrara Valley Region • Natural History Profiles of Some Niobrara Valley Wetland Species • The Niobrara Valley Wetlands

4 The Platte Valley Region • Natural History Profiles of Some Platte Valley Wetland Species • The Central Platte Valley Wetlands • The North Platte Valley Wetlands

5 Other River Valley Wetlands • Natural History Profiles of Some Typical Riverine Species • The Elkhorn Valley Wetlands • The Loup Valley Wetlands • The Republican Valley …

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 …

4th International Union Of Soil Sciences Soil Classification Conference Field Tour Guidebook

Conservation and Survey Division: Faculty and Staff Publications

No abstract provided.

North Central Region Soil Survey Conference Field Tour

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

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

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

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

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

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

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

The Compass: Earth Science Journal of Sigma Gamma Epsilon

No abstract provided.

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 39^th 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 19^th 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

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

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

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

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

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

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 δ¹⁸O_SW)(a …

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, …