Geology Commons^™

Holocene Cyclic Records Of Ice-Rafted Debris And Sea Ice Variations On The East Greenland And Northwest Iceland Margins, D. A. Darby, J. T. Andrews, S. T. Belt, A. E. Jennings, P. Cabedo-Sanz

OES Faculty Publications

The dynamics of the Greenland Ice Sheet and drift of sea ice from the Arctic Ocean reaching Denmark Strait are poorly constrained. We present data on the provenance of Fe oxide detrital grains from two cores in the Denmark Strait area and compare the Fe grain source data with other environmental proxies in order to document the variations and potential periodicities in ice-rafted debris delivery during the Holocene. Based on their Fe grain geochemistry, the sediments can be traced to East Greenland sources and to more distal sites around the Arctic Basin. On the Holocene time scales of the two …

Constraining Boundaries And Extent Of The Charleston Uplift, Northeast New Madrid Seismic Zone, Using Shallow Seismic Reflection Methods, Clara Rose Rucker

Theses and Dissertations--Earth and Environmental Sciences

A recently identified 30 km by 7.2 km subsurface stratigraphic uplift, called the Charleston uplift, exhibits 36 m offset of Paleogene-Quaternary unconformity based on shallow borehole data. Two seismic soundings demonstrated relief in Paleozoic and Cretaceous reflectors across the northern boundary of the uplift, suggesting a structural origin rather than an erosional origin. This study collected and analyzed 18 additional shallow seismic soundings to confirm Paleozoic and Cretaceous offset across the boundaries of the uplift, to better constrain the surface trace of the uplift, and to examine potential extension into western Kentucky. One ground penetrating radar profile was taken in …

Hydrogeochemical Controls On Reactive And Nonreactive Solute Transport In Heterogenous Porous Media, Mahta Gholizadeh Ansari

Masters Theses

"This work examines how physical and chemical heterogeneity can affect reactive and non-reactive transport in porous media. The effect of heterogeneity of the porous media is investigated both on dissolution rate of magnesite and attenuation time of nonreactive contaminants in non-reactive media. Various spatial distribution were created using statistical parameters in PETREL.A total of 6793 transport modeling simulations were run using CrunchFlow. Lasso regression was used to select most significant features and those features are then used in linear regression and deep learning models.

The magnesite dissolution simulations were performed under different permeability ratios (magnesite /sand permeability) and inlet pH. …

Comparison Of Acoustic Recorders And Field Observers For Monitoring Tundra Bird Communities, Skyler T. Vold, Colleen M. Handel, Lance B. Mcnew

United States Geological Survey: Staff Publications

Acoustic recorders can be useful for studying bird populations but their efficiency and accuracy should be assessed in pertinent ecological settings before use. We investigated the utility of an acoustic recorder formonitoring abundance of tundra-breeding birds relative to point-count surveys in northwestern Alaska, USA, during 2014. Our objectives were to 1) compare numbers of birds and species detected by a field observer with those detected simultaneously by an acoustic recorder; 2) evaluate how detection probabilities for the observer and acoustic recorder varied with distance of birds from the survey point; and 3) evaluate whether avian guild-specific detection rates differed between …

The Aerosphere As A Network Connector Of Organisms And Their Diseases, Jeremy D. Ross, Eli S. Bridge, Diann J. Prosser, John Y. Takekawa

United States Geological Survey: Staff Publications

Aeroecological processes, especially powered flight of animals, can rapidly connect biological communities across the globe. This can have profound consequences for evolutionary diversification, energy and nutrient transfers, and the spread of infectious diseases. The latter is of particular consequence for human populations, since migratory birds are known to host diseases which have a history of transmission into domestic poultry or even jumping to human hosts. In this chapter, we present a scenario under which a highly pathogenic avian influenza (HPAI) strain enters North America from East Asia via postmolting waterfowl migration. We use an agent-based model (ABM) to simulate the …

Co2 Adsorption On Volcanic Ash: Net Contribution Of Volcanic Eruptions To The Global Carbon Cycle, Lee New

Electronic Theses and Dissertations

Adsorption of co2 on mineral surfaces accounts for a small percentage of the terrestrial co2 sink. Volcanic ash is virtually free of co2 when erupted and has a high surface area resulting in a high capacity for co2 adsorption. Volcanism is commonly assumed to be only a source of co2, but pyroclastic eruptions can also potentially serve as a sink. Adsorption was investigated for 6 volcanic ash samples of andesitic composition from four volcanoes: Okmok, Redoubt, Spurr, and Tungurahua. The eruption of volcano redoubt released 0.75 x 109 metric tons of co2 and 55 x 109 kg of ash throughout …

Detection Of Sedimentary Depositional Cycles In The Salado Formation, Southeastern New Mexico, Scott Paul Milo

Electronic Theses and Dissertations

An abundance of evaporitic features is preserved throughout the approximately 2,000-foot-thick Salado formation that is present across west Texas and southeastern New Mexico. The formation and preservation of evaporitic features are largely influenced by hydrology, and so those found in the Salado represent an uninterrupted record of hydrogeologic conditions in what is now the southwestern United States during the late Permian. Because it is home to the Waste Isolation Pilot Plant (WIPP) repository chamber, the salado has been the subject of countless studies ranging from areas of sedimentology, to geochemistry, to geotechnical engineering, to hydrology. However, until now there have …

Seismic Anisotropy As A Function Of Mineralogy And Rock Type In Chester Gneiss Dome, Southeast Vermont, Brittany Watling

Wayne State University Theses

Our knowledge of composition and structure in middle and lower crustal rocks is limited due to restricted accessibility, and thus comes mainly from studies of seismic velocities. But isotropic seismic velocities are not sufficient to distinguish between the many possible rock types in the middle and lower crust. Seismic anisotropy is the directional dependence of seismic velocity, and may provide further constraints on mineralogy and rock type. This study is focused on characterizing the seismic anisotropy of rocks from the Chester dome in southeast Vermont. We have simplified the Chester dome rock types into four groups based on rock type …

Kentucky Stratigraphy, Stephen F. Greb

Map and Chart--KGS

No abstract provided.

Depositional Controls And Sequence Stratigraphy Of Lacustrine To Marine Transgressive Deposits In A Rift Basin, Lower Cretaceous Bluff Mesa, Indio Mountains, West Texas, Andrew Anderson

Open Access Theses & Dissertations

Successful hydrocarbon exploration in former rift basins of the South Atlantic pre-salt has generated interest in understanding depositional, diagenetic, and stratigraphic controls on pre-salt deposits. However, most studies to date have focused on attributes and controls on presalt lacustrine carbonate reservoir systems and little work has been done on the overlying marine sealing facies. Currently our standard sequence stratigraphic model of marine transgression of rift systems involves a single pulse of marine flooding over fluvially-incised valleys resulting in backstepping of fluvial and estuarine siliciclastic facies within the erosionally confined zone of an incised valley. However, the pre-salt systems of the …

Gypsum, Calcite, And Dolomite Caprock Fabrics And Geochemistry From The Gypsum Valley Salt Diapir, Paradox Basin, Southwestern Colorado, Kevin Lerer

Open Access Theses & Dissertations

Caprocks are found on top of or in a lateral position relative to salt diapirs. The caprocks predominantly comprise sulfate minerals such as anhydrite or gypsum, which presumably accreted during the dissolution of salt from evaporite sediments. In some cases, the sulfate minerals are replaced by carbonate minerals, referred to as "carbonate caprock". Carbonate caprocks associated with salt diapirs are important because they can act as reservoirs or conduits for hydrocarbons, and because they can be easily misidentified as carbonate lithologies belonging to the stratigraphy of the sedimentary sequences adjacent to the diapir, which can jeopardize the accurate interpretation of …

Genesis Of Unique Carbonate Fans In A Pre-Salt Reservoir Analogue, Indio Mountains, West Texas, Andre Llanos

Open Access Theses & Dissertations

Hydrocarbon exploration in pre-salt sediments of rift basins on the South Atlantic Margin have proven to be successful major oil plays. Located on the western margin of the rift, the Brazilian pre-salt reservoirs of the Santos, Campos, and Espirito Santo Basins are hosted by lacustrine/marine-influenced carbonates that comprise laterally extensive, laminated microbialite facies. The Indio Mountains, located in West Texas, provide well-exposed outcrops of Lower Cretaceous marine and non-marine rift basin strata that can be considered a reservoir-analog to the South Atlantic Margin pre-salt facies. Of particular interest for hydrocarbon exploration are unique carbonate features that have been discovered in …

Nebraska Statewide Groundwater-Level Monitoring Report 2016, Aaron R. Young, Mark E. Burbach, Leslie M. Howard, Michele M. Waszgis, R. Matthew Joeckel, Sue Olafsen Lackey

Conservation and Survey Division: Faculty and Staff Publications

The term “groundwater” has come to be all but synonymous with Nebraska. Nearly three-quarters of the volume of the High Plains aquifer lies beneath the State, and groundwater maintains our streams, our ecosystems, our people, and our vitally important agricultural economy. Although Nebraska’s total groundwater resource is vast, it is also quite vulnerable to changes induced by natural processes and by humankind, necessitating a long-term commitment to wise management through informed decision making. Monitoring, studying, and reporting are the essential basis for such management and, ultimately, for meeting the myriad challenges presented by change.

The personnel of the Conservation and …

The Oligocene West Elk Breccia: Evidence For Massive Volcanic Debris Avalanches In The Eastern Gunnison River Valley, West-Central Colorado, U.S.A., Patrick J. Whalen

Theses and Dissertations--Earth and Environmental Sciences

The West Elk Breccia has been studied since the late 1800’s with many interpretations regarding its origin. One unrecognized possibility is that parts of it are debris-avalanche deposits. This study has recognized evidence for this interpretation at three scales: volcano scale, outcrop scale, and intra-outcrop scale. At the volcano scale, a scarp in the old volcano reveals underlying Mesozoic bedrock, suggesting sector collapse. At the outcrop scale, megablocks of the original edifice, up to hundreds of meters in length, have atypical orientations and are surrounded by a gravel matrix. At the intra-outcrop scale, jigsaw-fit fracturing and rip-up clasts are common …

Initial Microseismic Recordings At The Onset Of Unconventional Hydrocarbon Development In The Rome Trough, Eastern Kentucky, Andrew Holcomb

Theses and Dissertations--Earth and Environmental Sciences

The Cambrian Rogersville Shale is a part of a hydrocarbon system in the Rome Trough of eastern Kentucky and West Virginia that can only be produced unconventionally. In Kentucky, the Rogersville Shale ranges in depth from ~1,800 to ~3,700 m below the surface with the crystalline basement ~1,000 m lower than the formation’s base. Baseline Rome Trough microseismicity data were collected, focusing on wastewater injection wells and recently completed and planned unconventional hydrocarbon test wells in the Rogersville Shale, using thirteen broadband seismic stations installed between June, 2015 and June, 2016 and existing University of Kentucky and central and eastern …

Potential Field Modeling Across The Neodymium Line Defining The Paleoproterozoic-Mesoproterozoic Boundary Of The Southeastern Margin Of Laurentia, Rachel Lauren Durham

Theses and Dissertations--Earth and Environmental Sciences

A zone of high magnetization along the SE margin of Paleoproterozoic Laurentia in the United States is indicated by magnetic anomaly data. The SE edge corresponds to the geochemical Neodymium mantle derivation model age (T_DM) boundary and the entire anomaly overlies the Paleoproterozoic Mazatzal Province. Two-dimensional gravity and magnetic models across the Nd boundary are created with Moho constrained from receiver functions with gravity, sedimentary thickness and the base of the crustal magnetization. Upper crustal magnetization does not show strong variation across this boundary and much of the strong magnetization appears to lie in the middle crust. Using …

Effects Of Hydrologic Connectivity And Land Use On Floodplain Sediment Accumulation At The Savannah River Site, South Carolina, Jeremy E. Eddy

Theses and Dissertations--Earth and Environmental Sciences

Floodplains, and the sediment accumulating naturally on them, are important to maintain stream water quality and serve as sinks for organic and inorganic carbon. Newer theories contend that land use and hydrologic connectivity (water-mediated transport of matter, energy, and/or organisms within or between elements of the hydrologic cycle) play important roles in determining sediment accumulation on floodplains. This study hypothesizes that changes in hydrologic connectivity have a greater impact on floodplain sediment accumulation than changes in land use. Nine sediment cores from seven sub-basins were collected from the Savannah River Site (SRS), South Carolina, and processed for grain-size, radionuclide dating …

Utilizing Structure-From-Motion Photogrammetry And Unmanned Aerial Vehicles To Characterize Variability In Fluvial Deposits From The Salt Wash Member Of The Morrison Formation, East-Central Utah, John Chesley

Theses and Dissertations

Modern fluvial systems are highly variable, often containing the entire spectrum of fluvial styles (e.g., braided to meandering). This variability is difficult to capture in ancient fluvial deposits due to limited 1- and 2-dimesional exposures, which provide only a snapshot of the depositional history at one location. As a result, researchers are forced to interpolate between exposures and develop regional scale models that often underestimate the complexity and variability seen in modern environments. Outcrops of the Upper Jurassic Salt Wash Member of the Morrison Formation in east-central Utah, USA provide a relatively unique opportunity to examine ancient fluvial sandstone bodies …

Lake Magadi And The Soda Lake Cycle: A Study Of The Modern Sodium Carbonates And Of Late Pleistocene And Holocene Lacustrine Core Sediments, Emma Mcnulty

Graduate Dissertations and Theses

The Magadi Basin, Kenya, within the East African Rift Valley, contains two closed-basin alkaline lakes, Lake Magadi and Nasikie Engida that now precipitate trona (Na2CO3.NaHCO3.2H2O) and nahcolite (NaHCO3). Observations of the conditions of modern trona and nahcolite deposition in the Magadi Basin form the basis of the “soda lake cycle”. This study aims to use the sedimentary structures of the modern sodium carbonates of Lake Magadi as an analogue for similar ancient deposits around the world, including the vast trona and nahcolite deposits of the Eocene Green River Formation. Lake Magadi has been evolving since 1.08 Ma within a well-known …

Imaging Bioturbation In Supratidal Carbonates: Non-Invasive Field Techniques Enhance Neoichnological And Zoogeomorphological Research, San Salvador, The Bahamas, Karen Kopcznski, Ilya Buynevich, H. Allen Curran, Jon Caris, Jonathan Nyquist

Geosciences: Faculty Publications

A case study in unconsolidated carbonates on San Salvador Island, The Bahamas, utilized high-frequency (800 MHz) georadar imaging to augment existing methodologies (burrow counts and measurements, casting) in brachyuran bioturbation research (Ocypode quadrata and Gecarcinus lateralis), and as part of a new dataset characterizing blue land crab (Cardisoma guanhumi) burrows. Non-invasive techniques such as ground-penetrating radar (GPR) can complement traditional field surveys aimed at quantifying mesoscale bioturbation in modern settings. These methods can establish diagnostic features for tracemaker identification and refine existing ichnofacies models. Drone-mounted aerial coverage provided the first high-resolution images of the micro-topography and …