Sedimentology Commons^™

Holdrege: Nebraska's State Soil, University Of Nebraska - Lincoln

Conservation and Survey Division: Faculty and Staff Publications

No abstract provided.

Holdrege Nebraska State Soil, Nebraska Society Of Professional Soil Scientists

Conservation and Survey Division: Faculty and Staff Publications

No abstract provided.

Influences Of Hurricanes, Floods, And Organic Production On River-Delta Evolution Over Decadal To Centennial Time-Scales, Crawford M. White

LSU Doctoral Dissertations

Episodic overbank flooding and sediment resuspension events (such as cold front passages or tropical cyclones) are recognized as important natural components for wetlands maintaining vertical equilibrium with sea-level. However, the relative importance of these components to an anthropogenically unmodified delta complex remains unclear. This study uses sediment cores to describe the relative importance of these vertical accretion components the Lafourche and Balize Deltas of the Mississippi River. Existing wetlands of the abandoned lower Lafourche receive no direct fluvial sediment, but instead are supported by sediment resuspended by tropical cyclones and cold fronts that pass over them. Wetlands of the modern …

Investigating Core Shale Depositional Environments Of Late Pennsylvanian Cyclothems Utilizing Geochemical Proxies To Test The Superestuarine Model, Bryce A. Mathis

LSU Master's Theses

The Late Paleozoic Midcontinent Sea (LPMS) inundated vast areas of the North American interior during glacio-eustatic transgressions, depositing widespread black shales facies within the core shale intervals of major cyclothems. These black shale deposits are unique because no modern analogs can adequately explain the depositional environments and model for organic matter preservation across such vast ancient epicontinental settings. One possible explanation is that a superestuarine circulation system developed across the LPMS during humid interglacial phases, which promoted strong water column stratification and benthic anoxia.

The goal of this research was to test the validity of the superestuarine estuarine model and …

Sedimentary Characteristics And Nutrient Sequestration Of Embanked Floodplains Along The Lower Mississippi River, Mississippi And Louisiana, R M Malitha Rathnayake

Master's Theses

The Mississippi River Basin is the largest river basin in North America and the third largest river basin in the world. Most of the corn, soybeans, wheat, cattle, and hogs harvested in the United States come from the Mississippi River Basin and about 58% of the entire drainage basin is croplands. Runoff from these lands carries sediments and nutrients, and the Mississippi River transports these downstream and ultimately deposits them in the Gulf of Mexico. The northern Gulf of Mexico is one of largest human-caused hypoxic zones in the world. Hypoxia is the phenomena where the dissolved oxygen level decreases …

Geology And Paleontology Along Part Of The Niobrara River In Northern Nebraska, Robert Matthew Joeckel, S. T. Tucker, Leslie M. Howard

Conservation and Survey Division: Faculty and Staff Publications

No abstract provided.

Stratigraphy, Petrology, And Paleontology Of The Late Cretaceous Campanian Mesaverde Group In Northeastern Utah, Christopher Ward

All Graduate Plan B and other Reports, Spring 1920 to Spring 2023

This project examines a poorly studied sandstone ridge called Snake John Reef located 22 miles southeast of Vernal, in northeastern Utah. Previously this ridge was mapped as exposures of late Cretaceous, undifferentiated Mesaverde Group, and recently unidentified dinosaur fossils have been found along the ridge by the Utah Field House of Natural History State Park Museum. Stratigraphic sections, petrographic thin sections, and collection and study of fossils from Snake John Reef were undertaken to understand the stratigraphic relationship as well as to reconstruct the depositional environment of the dinosaur bearing units. Snake John Reef represents exposures of three late Cretaceous …

Using Stable Isotope Geochemistry To Determine Changing Paleohydrology And Diagenetic Alteration In The Late Cretaceous Kaiparowits Formation, Ut Usa, Daigo Yamamura

Graduate Theses and Dissertations

The Western Interior Basin of the North America preserves one of the best sedimentary and paleontological records of the Cretaceous in the world. The Upper Cretaceous Kaiparowits Formation is a rapidly deposited fluvial sequence and preserves one of the most complete terrestrial fossil record of the North America. Such a unique deposit provides an opportunity to investigate the interaction between the physical environment and ecology. In an effort to decipher such interaction, stable isotope composition of cements in sedimentary rocks, concretions and vertebrate fossils were analyzed.

Despite the difference in facies and sedimentary architecture, the isotope composition does not change …

Quantifying Riverbed Sediment Using Recreational-Grade Side Scan Sonar, Daniel Hamill

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

The Colorado River in Glen, Marble, and Grand Canyons is subject to a complex regulatory framework, including the Colorado River Compact, the Endangered Species Act, and the Grand Canyon Protection Act of 1992. Physical, biological, and cultural resources are extensively monitored by the Glen Canyon Dam Adaptive Management Program (GCDAMP) to assess the effect of Glen Canyon Dam (GCD) operations on the downstream environment. The GCDAMP consists of a diverse group of stakeholders who identify priority resources and agree upon water releases at GCD. Large expenditures of money have been devoted to monitoring physical and biological resources in Grand Canyon. …

Microfeatures Of Modern Sea-Ice-Rafted Sediment And Implications For Paleo-Sea-Ice Reconstructions, Kristen E. St. John, Sandra Passchier, Brooke Tantillo, Dennis Darby, Lance Kearns

Department of Earth and Environmental Studies Faculty Scholarship and Creative Works

Distinguishing sea-ice-rafted debris (SIRD) from iceberg-rafted debris is crucial to an interpretation of ice-rafting history; however, there are few paleo-sea-ice proxies. This study characterizes quartz grain microfeatures of modern SIRD from the Arctic Ocean, and compares these results with microfeatures from representative glacial deposits to potentially differentiate SIRD from ice-rafted sediments which have been recently subjected to glacial processes. This allows us to evaluate the use of grain microfeatures as a paleo-sea-ice proxy. SIRD grains were largely subrounded, with medium relief, pervasive silica dissolution and a high abundance of breakage blocks and microlayering. The glacial grains were more angular, with …

Stratigraphic Architecture And Lithofacies Of High-Frequency Deltaic Sequences: Virtual Outcrop Analysis Of The Upper Cretaceous (Turonian) Ferron Sandstone Member Of The Mancos Shale, South-Central Utah, Usa, Conor J. Horton

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

Sequence stratigraphic models for low-accommodation settings are not well-formulated and lack documented examples illustrating lithofacies stratal stacking pattern complexities. Presented herein is a detailed stratigraphic analysis of the Upper Cretaceous (Turonian) Ferron Sandstone Member of the Mancos Shale Formation; a fluvial-deltaic succession that primarily accumulated under forced-regressive, falling stage systems tracts during decreasing accommodation. The small (4 km2) study area is located at the connecting point of a 67 km long, depositional strike-oriented and a 30 km long, depositional-dip transect within the western-limb of the Henry Mountains Syncline. Detailed outcrop sections and digital Light Detection and Ranging (LiDAR) derived Virtual …

Evidence For Late Pliocene Deglacial Megafloods From Giant Sediment Waves In The Northern Gulf Of Mexico, Zexuan Wang

Masters Theses & Specialist Projects

Laurentide Ice Sheet outburst floods to the Gulf of Mexico have been mainly documented based on deep-sea cores, especially the megafloods, only during the last several interglacial episodes in the late Pleistocene. The paleoclimatic significance of giant sedimentary structures developed under unconfined Froude-supercritical turbidity currents in subaqueous settings is considerably under-examined. This research extensively documents >20-km-wide and 200-m-thick Plio-Pleistocene giant sediment waves for the first time on the northern Gulf of Mexico continental slope using 3D seismic data, which show waveform morphology in unprecedented detail. The results suggest that such large-scale bedforms were formed under sheet-like unconfined Froudesupercritical turbidity currents …

An Overview Of Secondary Aquifers In Nebraska, Dana Divine, Steven S. Sibray

Conservation and Survey Division: Faculty and Staff Publications

No abstract provided.

Interpretive Geologic Cross Sections Across Lower Platte North Natural Resources District, Nebraska (Ccs-20), Dana Divine

Conservation and Survey Division: Faculty and Staff Publications

No abstract provided.

Growth Laws For Sub-Delta Crevasses In The Mississippi River Delta: Observations And Modeling, Tara A. Yocum

LSU New Orleans Theses and Dissertations

In this study we assessed growth laws of sub-delta crevasses in the Mississippi River delta plain, experimental laboratory deltas, and compared them to previously studied river dominated large deltas worldwide. Metrics for channel and delta geometry for each system were obtained using a combination of geospatial tools, bathymetric datasets, sediment size, and hydrodynamic observations. Most crevasses and experimental deltas appear to obey delta growth laws suggesting that they exhibit planform metrics similar to larger deltas. However, some channels within each system, exhibit outlier behavior (e.g. asymmetric growth) where channel length is much larger than channel width. Hydrodynamic observations and morphodynamic …

Lithology And Depositional Environments Of A Portion Of The Clays Ferry Formation (Middle And Upper Ordovician) Exposed At Silver Creek, Madison County, Kentucky, Autumn Murray

EKU Faculty and Staff Scholarship

We measure, describe, and interpret a carbonate stratigraphic section within the Clays Ferry Formation (Middle and Upper Ordovician) cropping out in Madison County, Kentucky (USGS Kirksville 7.5” quadrangle). The total thickness of the measured section is 4.76 m. We sampled the stratigraphic section at approximately half-meter intervals, also taking samples at lithology changes. We collected a total 20 samples, all of which were slabbed, and then selected 12 samples for thin section analysis.

Observed lithologies represent discrete depositional environments. The rocks are dominantly limestones with some carbonate shales deposited in shallow-water depositional environments that are generally open-marine, subtidal with perhaps …

Channel Bar Morphology, Distribution, And Mining-Related Geochemistry In The Big River, St. Francois County, Missouri: Implications For Geomorphic Recovery, Lindsay Marie Olson

Graduate Theses/Dissertations

Tailings releases associated with large-scale historical Pb mining in St. Francois County, Missouri resulted in system-wide contamination of Pb and excess sediment in the Big River. Previous studies have addressed basin and segment scale variability of the contaminants; however, little is known about reach and bar scale variability. This study addresses how mining sediment inputs influence bar form and geochemistry across a range of scales. Bar sediment samples were collected at 21 reaches and analyzed for particle size and geochemistry, while air photo analysis was used to evaluate channel morphology, bar type, and area. Bar area is initially low in …

Cyclostratigraphic Trends Of Δ13c In Upper Cambrian Strata, Great Basin, Usa: Implications For Astronomical Forcing, Wesley Donald Weichert

Graduate Theses/Dissertations

Composite geochemical studies of carbonate isotope values (δ13C) by other investigators have established that the Cambrian period is punctuated by a series of significant, globally correlated, positive and negative δ13C excursions. However, it remains unclear if low-amplitude secular variations in δ13C values exist superimposed on, or between large-scale perturbations in the Cambrian carbon cycle, especially in cyclic successions. Rocks of Steptoean-Sunwaptan (Paibian-Jiangshanian) stage, exposed in the Great Basin of Utah and Nevada, are excellent candidates for testing the hypothesis that sedimentary cycles record minor variations in Earth's orbit (Milankovitch cycles) through application of high-resolution chemostratigraphic analysis. High-resolution δ13C data was …

Using Survey Data And Hec-Ras Modeling To Assess A Riffle-Remediation Structure On The Big River, Bonne Terre, Missouri, Nichole Renee Weedman

Graduate Theses/Dissertations

Sediment transport and deposition in river channels can vary for many reasons including flooding, dredging, channel velocity, and grain size. On the Big River, the Army Corps of Engineers constructed a riffle ramp structure to trap and remediate lead-contaminated sediments. The performance of the structure is unknown. The goal of this study is to evaluate the storage capabilities of the riffle structure. To do this, survey data was collected to analyze sediment storage and entered into the HEC-RAS 5.0 to model the hydraulics of the channel before and after the riffle installation. Samples were collected to assess the level of …

Environmental Changes Across The Early Mississippian Carbon Isotope Excursion, Dev Krishna Maharjan

UNLV Theses, Dissertations, Professional Papers, and Capstones

The Early Mississippian K–O (Kinderhookian-Osagean) δ13C excursion or TICE (mid-Tournaisian carbon isotope excursion) is characterized by an anomalous carbonate carbon isotope value of ≥5‰ that has been documented from numerous stratigraphic sections across the globe. This δ13C excursion coincides with global cooling and sea-level fall and predicts a significant change in seawater chemistry. However, sulfate sulfur isotope data across the K-O δ13C excursion reported in previous studies seem not to be responsive to the carbon cycle. Likewise, a recent study has documented a unidirectional increase in nitrogen isotopes across this excursion, which is not anticipated considering the amount of organic …