Geology Commons^™

A Global Standard For Monitoring Coastal Wetland Vulnerability To Accelerated Sea-Level Rise, Edward L. Webb, Daniel A. Friess, Ken W. Krauss, Donald R. Cahoon, Glenn R. Guntenspergen, Jacob Phelps

United States Geological Survey: Staff Publications

Sea-level rise threatens coastal salt-marshes and mangrove forests around the world, and a key determinant of coastal wetland vulnerability is whether its surface elevation can keep pace with rising sea level. Globally, a large data gap exists because wetland surface and shallow subsurface processes remain unaccounted for by traditional vulnerability assessments using tide gauges. Moreover, those processes vary substantially across wetlands, so modelling platforms require relevant local data. The low-cost, simple, high-precision rod surface-elevation table–marker horizon (RSET-MH) method fills this critical data gap, can be paired with spatial data sets and modelling and is financially and technically accessible to every …

Use Of Nmr Logging To Obtain Estimates Of Hydraulic Conductivity In The High Plains Aquifer, Nebraska, Usa, Katherine Dlubac, Rosemary Knight, Yi-Qiao Song, Nate Bachman, Ben Grau, Jim Cannia, John Williams

United States Geological Survey: Staff Publications

Hydraulic conductivity (K) is one of the most important parameters of interest in groundwater applications because it quantifies the ease with which water can flow through an aquifer material. Hydraulic conductivity is typically measured by conducting aquifer tests or wellbore flow (WBF) logging. Of interest in our research is the use of proton nuclear magnetic resonance (NMR) logging to obtain information about water-filled porosity and pore space geometry, the combination of which can be used to estimate K. In this study, we acquired a suite of advanced geophysical logs, aquifer tests, WBF logs, and sidewall cores at the …

Spatially Explicit Models For Inference About Density In Unmarked Or Partially Marked Populations, Richard B. Chandler, J. Andrew Royle

United States Geological Survey: Staff Publications

Recently developed spatial capture-recapture (SCR) models represent a major advance over traditional capture-recapture (CR) models because they yield explicit estimates of animal density instead of population size within an unknown area. Furthermore, unlike non-spatial CR methods, SCR models account for heterogeneity in capture probability arising from the juxtaposition of animal activity centers and sample locations. Although the utility of SCR methods is gaining recognition, the requirement that all individuals can be uniquely identified excludes their use in many contexts. In this paper, we develop models for situations in which individual recognition is not possible, thereby allowing SCR concepts to be …

The Geologic Records Of Dust In The Quaternary, Daniel R. Muhs

United States Geological Survey: Staff Publications

Study of geologic records of dust composition, sources and deposition rates is important for understanding the role of dust in the overall planetary radiation balance, fertilization of organisms in the world’s oceans, nutrient additions to the terrestrial biosphere and soils, and for paleoclimatic reconstructions. Both glacial and non-glacial processes produce fine-grained particles that can be transported by the wind. Geologic records of dust flux occur in a number of depositional archives for sediments: (1) loess deposits; (2) lake sediments; (3) soils; (4) deep-ocean basins; and (5) ice sheets and smaller glaciers. These archives have several characteristics that make them highly …

Abiotic Nitrate And Nitrite Reactivity With Iron Oxide Minerals, Prakash Dhakal

Theses and Dissertations--Plant and Soil Sciences

Under iron (Fe³⁺)-reducing conditions where aqueous Fe²⁺ and unreduced solid Fe³⁺-oxides commonly coexist, soil Fe²⁺ oxidation has been shown to be coupled with nitrate (NO₃^-) reduction. One possible secondary reaction is the involvement of NO₃^- and nitrite (NO₂^-) with Fe-oxide minerals found in many natural environments. Yet, spectroscopic measurements and kinetic data on reactivity of NO₃^- and NO₂^- with Fe-containing oxide minerals such as goethite (a-FeOOH), and magnetite (Fe₃O­₄) are not found in the literature. The reactivity of …

Lithological And Sequence Stratigraphic Examination Of The Madison Group Marker Beds, Eastern Williston Basin Margin, North Dakota, Troy Jd. Skitt

Theses and Dissertations

The Frobisher-Alida interval consists of eight log-defined subintervals or “beds” within the Mississippian upper Mission Canyon and lower Charles Formations of the Madison Group in the Williston Basin. The subintervals are composed of predominantly evaporite and carbonate lithologies, and include in descending order: 1) Midale, 2) Rival, 3) Bluell, 4) Sherwood, 5) Mohall, 6) Glenburn, 7) Wayne, and 8) Landa. The top of the lower six subintervals are separated by thin but areal extensive log-defined markers of contrasting lithologies and include in descending order: 1) State A, 2) Sherwood Argillaceous Marker (S.A.M.), 3) K-1, 4) K-2, 5) K-3, and 6) …

Characterization Of Mass Wasting Through The Spectral Analysis Of Lidar Imagery: Owyhee River, Southeastern Oregon, Christopher Earl Markley

All Master's Theses

Quantifying landslide character is an important aspect of understanding hillslope-channel interactions. Spectral analysis of high-resolution, LiDAR derived, DEMs was carried out following methods described by Booth et al. (2009) to determine the characteristic spectral signature inherent in different styles of landslides in the Owyhee River Canyon in southeastern Oregon. The main factor in landslide generation in this location is a lithologic contact in which a coherent basaltic caprock overlies relatively weak sediments where most of the landslide failure surfaces originated. Changes in spectral power distribution through time were quantified by comparing a sequence of adjacent rotational landslides of apparent different …

A Comparison Of Pixel-Based Versus Object Oriented Analysis Of Landslides Using Historical Remote Sensing Data, Ren N. Keyport

Dissertations, Master's Theses and Master's Reports - Open

With recent advances in remote sensing processing technology, it has become more feasible to begin analysis of the enormous historic archive of remotely sensed data. This historical data provides valuable information on a wide variety of topics which can influence the lives of millions of people if processed correctly and in a timely manner. One such field of benefit is that of landslide mapping and inventory. This data provides a historical reference to those who live near high risk areas so future disasters may be avoided. In order to properly map landslides remotely, an optimum method must first be determined. …

Geol 440/840: Tectonics—A Peer Review Of Teaching Project Inquiry Portfolio, Caroline M. Burberry

UNL Faculty Course Portfolios

This document is a follow-up document to the Benchmark Portfolio for this course, created in 2012. It details the changes made to the course following the observations from the Benchmark Portfolio and demonstrates that discussion of the metacognitive issues surrounding critical thinking does have some effect on increasing student learning. The document concludes with changes which will be made to the 2014 iteration of the class, to continue this inquiry and improvement process.

Geol 106: Environmental Geology—A Peer Review Of Teaching Project Benchmark Portfolio, Leilani Arthurs

UNL Faculty Course Portfolios

The Peer Review of Teaching (PRT) program provides faculty members the environment, support, structure, and time to carefully think about how they teach a particular course. PRT benchmark portfolios are prepared as a part of this program to assist faculty members in reflecting on and documenting their instructional practices and the potential impact they have on student learning.

This benchmark portfolio targets the Spring 2013 semester of GEOL 106: Environmental Geology. It documents the course objectives that provided the foundation for the instructional approach, the course-level learning goals that defined what students should be able to do by the end …

Geochemical And Isotopic Characterization Of Lead In Fugitive Dust From Unsurfaced Roads In Missouri, Emitt C. Witt

Doctoral Dissertations

"Eighteen unsurfaced roadways in Missouri's rural Ozark region were sampled to characterize the differences in trace element and isotopic chemistry to determine if there is a human health concern with inhaling and/or ingestion of fugitive dust generated by a moving vehicle. Road reaches were selected to represent those in similar rural areas with and without the presence of mining activity--13 roads were selected in the Viburnum Trend (VT) resource mining area and five were located to the southwest of the mining areas. Samples were collected using a novel cyclonic fugitive dust sampler (patent pending) that collects a composite sample from …

Palynology Of Acid-Saline Lakes Of Western Australiabiostratigraphy And Paleoenvironmental Reconstruction, Carlos A. Sanchez Botero

Doctoral Dissertations

"Lakes are excellent repositories of fossils and sedimentary features that provide clues to past climatic and geologic events. Sediments from four cores drilled in Lake Aerodrome (LA1-09, LA2-09) and Lake Brown (LB1-09, LB2-09), two of the hundreds of ephemeral lakes in southern Western Australia, were analyzed for their palynological contents to understand the geologic and climatic evolution of the depositional basin. Palynofacies assemblages defined by statistical analyses of dispersed organic matter suggested differences in the depositional conditions and probable correlations between Lake Aerodrome cores. Detailed identifications and quantification of organic-walled microfossils yielded two palynomorph assemblages that reflect a climatic turnover: …

Sediment Impact On The Formation Of Hypoxic Waters In The Northern Gulf Of Mexico: A Synthesis Of Sediment Texture, Composition, Erodibility And Transport, Rangley Claude Mickey

Electronic Theses and Dissertations

Annual hypoxic events have been found to occur over the past several decades in the northern Gulf of Mexico (nGOM) and have prompted researchers to begin studying the mechanisms that control hypoxia formation so they may advise policy makers on the appropriate mitigating responses. This has led to the development of 3-dimensional modeling systems that incorporate marine physical, biological, geological, and chemical processes that may impact the formation and duration of hypoxic regimes in the nGOM. This study used field, laboratory, and modeling techniques to examine how sediment may be eroded from the seabed and where/how it is transported across …

A History Of Place: Using Phytolith Analysis To Discern Holocene Vegetation Change On Sanak Island, Western Gulf Of Alaska, Cricket C. Wilbur

Antioch University Dissertations & Theses

This study investigated a terrestrial climate proxy, phytoliths, as a complimentary approach to documenting the dynamics of present and past vegetation on Sanak Island, the largest island in a small island group in the eastern Aleutian archipelago, and as a new basis by which to interpret Holocene environmental variability in Alaska. A phytolith reference collection was established from 59 selected plant species of maritime tundra belonging to 27 families. The grass species and a sedge species produced abundant phytolith forms whereas the majority of dicotyledons in this study were trace producers of phytoliths. A paleoenvironmental reconstruction from fossil phytoliths recovered …

Are 34s-Enriched Authigenic Sulfide Minerals A Proxy For Elevated Methane Flux And Gas Hydrates In The Geologic Record?, Walter S. Borowski, Nancy M. Rodriguez, Charles K. Paull, William Ussler Iii

EKU Faculty and Staff Scholarship

The sulfate–methane transition (SMT) zone is a diagenetic transition within anoxic marine sediments created by the metabolic activity of a consortium of sulfate-reducing bacteria and methane-oxidizing Archaea. As interstitial dissolved sulfate is consumed by microbially mediated sulfate reduction of sedimentary organic matter (SOM) and anaerobic oxidation of methane (AOM) large enrichments of ³⁴S occur in the interstitial sulfate pool. These isotopic enrichments are transmitted to the dissolved sulfide pool (∑HS⁻) and subsequently into sulfide minerals (So, ∼FeS, FeS₂).

We investigate the sulfur isotopic composition of pore-water sulfate and sulfide minerals at three sites underlain …

Subsurface Imaging And Petrophysical Analysis Of The South Georgia Rift Basin, South Carolina, Olusoga Martins Akintunde

Theses and Dissertations

The Triassic-Jurassic South Georgia Rift (SGR) basin, buried beneath Coastal Plain sediments of southern South Carolina, southeastern Georgia, western Florida, and southern Alabama, consists of an assemblage of continental rift deposits (popularly called red beds), and mafic igneous rocks (basalt flows and diabase sills). The red beds are capped by basalts and/or diabase sills, and constitute the target for supercritical CO2 storage as part of a Department of Energy funded project to study feasibility for safe and long-term sequestration. This study addresses key stratigraphic, structural and petrophysical issues critical to determine subsurface suitability for CO2 storage as well as improved …

Benthic Boundary Layer Processes: Bedform Evolution And Bottom Turbulence, Timothy Robert Nelson

Theses and Dissertations

Bedform roughness, caused by ripples on the seabed, plays an important role in controlling sediment dynamics in the nearshore region. In this dissertation, the temporal and spatial evolution of ripples from two field sites located in the South Atlantic Bight, offshore Long Bay, SC and Georgia are used to relate wave-induced ripple geometry (wavelength and orientation) to near bed directional wave velocities. 2-D spectral analysis techniques were developed to automate detection of ripple wavelength, direction, and irregularity. This analysis showed that magnitude, direction, and duration of wave forcing controls ripple geometry and irregularity. During highly energetic events, ripple geometry changes …

Volcanic And Tectonic Processes Along Anomalous Mid-Ocean Ridges, Julia Kathryn Howell

Theses and Dissertations

The morphological and structural characteristics of the global spreading ridge system are systematically related to spreading rate and magma supply (e.g. Macdonald, 1982). Because intermediate spreading-rate ridges (ISRs) spreading between 60 and 80 mm/yr have characteristics of both fast and slow spreading ridges, they are ideal environments to study the differences controlling upper crustal accretion. We examine the distribution of seamounts along spreading ridges to understand the relationship between seamount volcanism and axial morphology along four ISRs: the Juan de Fuca Ridge (JdFR), the Galápagos Spreading Centers (GSC), the Southeast Indian Ridge (SEIR), and the Eastern Lau Spreading Centers (ELSC). …

Geochemical Source Components In Seafloor Lavas In The Aleutian Back-Arc, Max Thomas Siegrist

Theses and Dissertations

Whole-rock compositions of seafloor lavas are used to constrain the processes and source characteristics contributing to the formation of geochemically distinctive, primitive magma types located in the Aleutian back-arc. Samples were dredged primarily from small volcanic cones on the seafloor, located between the emergent volcanoes and in the back-arc up to 60 km from the volcanic front. Compositions vary from basalt to dacite, with 48-70 % SiO₂ and 4-13 % MgO. Nearly 30% of the samples are primitive, with Mg/Mg+Fe >0.60. Most primitive samples are basalts, which fall into two groups, based on minor and trace element abundances. Low/med-K …

Morphological Changes Associated With Tropical Storm Debby In The Vicinity Of Two Tidal Inlets, John's Pass And Blind Pass, West-Central Florida, Andrew Brownell

USF Tampa Graduate Theses and Dissertations

Tropical Storm Debby affected the Gulf coast of Florida in late June, 2012. The storm's southerly approach temporarily reversed the annual net southward longshore sediment transport. The energetic conditions associated with Tropical Storm Debby can be seen in the wind, wave and tidal measurements taken from both onshore and offshore weather stations around the dual tidal inlets system of John's Pass and Blind Pass, approximately 25 kilometers north of the mouth of Tampa Bay. The energetic and persistent southerly forcing, in addition to higher storm induced water levels and wave heights, resulted in atypical beach erosion and sediment deposition on …