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Mechanisms Of Gold Enrichment In Seafloor Massive Sulfide Deposits: A Study On The Higashi-Aogashima Hydrothermal Field, Claudia Martinez

UNLV Theses, Dissertations, Professional Papers, and Capstones

The study of Seafloor Massive Sulfides (SMS) deposit formation is vital for assessing both the economic potential and environmental risks posed by future marine mining projects. Metal-rich SMS deposits form in hydrothermal vent systems within tectonically active regions, such as back-arc basins, where faults enhance crustal permeability, enabling fluid migration driven by magmatic heat sources at depth in the crust. Currently our understanding of SMS formation processes is based on bulk-rock geochemical and isotopic data, lacking the necessary spatial and temporal resolution to understand ore forming processes. As a result, critical gaps remain in understanding the exact mechanisms responsible for …

Predicting Ph At In-Situ Temperature For Aquatic Environments, Sarah E. Bartoloni

USF Tampa Graduate Theses and Dissertations

pH is typically measured at a constant temperature and, as needed, converted to in-situ temperature using a system of thermodynamic equations. Using this equilibrium approach, adjustment of pH to in situ conditions requires two measured CO2 system parameters (pH, total alkalinity, dissolved inorganic carbon, or CO2 fugacity). Currently, when pH is the only measured CO2 system parameter, linear models are used to adjust the pH to in-situ temperature. Although many studies have attempted to optimize CO2 equilibrium constants (K1 and K2) for the CO2 system over a range of conditions, very little prior work has experimentally examined which CO2 system …

Hydrological Dynamics Of Surface-Groundwater Interactions Between Major Springs Of Mammoth Cave And The Green River, Kentucky, Usa, Matthew Cecil

Masters Theses & Specialist Projects

Mammoth Cave is an iconic example of the cave and karst systems that underlie over 50% of the United States and provide around 13% of the world’s population with water resources. These environmental features are vulnerable to drought, pollution, and human impacts. The complex hydrological regime of the Mammoth Cave system has been studied in the past, but there are improvements and updates that can be made to the past research. The dynamics of the surface-groundwater system, particularly reversals of the Green River and how it backfloods into the cave, are some examples. Echo River and River Styx Springs provide …

Very High Middle Miocene Surface Productivity On The U.S. Mid-Atlantic Shelf Amid Glacioeustatic Sea Level Variability, Marci M. Robinson, Harry J. Dowsett, Timothy D. Herbert

United States Geological Survey: Staff Publications

The Miocene Climatic Optimum (MCO) provides important insights into how the climate system operates under elevated temperatures and atmospheric CO₂ levels. Few western North Atlantic paleotemperature or paleoecological records exist from the MCO, despite their importance for understanding both regional and global climate dynamics. Here we present quantitative MCO paleoecological data from the western North Atlantic, specifically from the Baltimore Gas & Electric (BG&E) marine sediment core from southern Maryland, USA. We examine alkenones and planktic foraminifera and document the first sea surface temperature (SST) and productivity estimates for the MCO and the Middle Miocene Climate Transition (MMCT) from …

Data Fusion And Synergy Of Active And Passive Remote Sensing; An Application For Freeze Thaw Detections, Zahra Sharifnezhadazizi

Dissertations and Theses

There has been a recent evolvement in the field of remote sensing after increase of number satellites and sensors data which could be fused to produce new data and products. These efforts are mainly focused on using of simultaneous observations from different platforms with different spatial and temporal resolutions. The research dissertation aims to enhance the synergy use of active and passive microwave observations and examine the results in detection land freeze and thaw (FT) predictions. Freeze thaw cycles particularly in high-latitude regions have a crucial role in many applications such as agriculture, biogeochemical transitions, hydrology and ecosystem studies. The …

Simulating Cambrian Climate: The Significance Of Atmospheric Co2 Concentration And Continental Position, Grace Cutting

Ursidae: The Undergraduate Research Journal at the University of Northern Colorado

The Cambrian Period began approximately 541 million years ago, and is known for the “Cambrian Explosion”, a time when multicellular life began to rapidly diversify. There is natural historic evidence (isotopes, rock formations, and fossils) that suggests the Cambrian Period experienced a warm climate. However, there is also conflicting evidence that the Cambrian climate may have undergone freezing and thawing cycles, with ice possibly present near the equator. It is critical to understand how ecosystems were able to adapt to past climate changes, especially when analyzing the impacts of modern human activity on climate. Climate model simulations were run to …

Characterization Of Uranium, Lead, And Rare Earth Element Pollution In Natural Soils And Sediments, Hope Rasmussen

Civil and Environmental Engineering Theses and Dissertations

Heavy metals in the environment add to the global burden of pollution, negatively impacting public health and ecosystem resilience. This study included projects regarding uranium (U), lead (Pb), and rare earth elements (REE) in natural samples, due to their known toxicity, ubiquity, and relevance in context to recent pollution trends. The first project focused on testing the potential of using a hydroxyapatite product as a remediation solution for U-contaminated groundwater and soil at an EPA Superfund site. The results showed that the U was sequestered in a highly crystalline mineral form within the solids, guiding the EPA to specify the …

Looking Past, Looking Forward: America's National Parks, Archaeology And Climate Change, Rachel Marie Blumhardt

Undergraduate Theses, Professional Papers, and Capstone Artifacts

America’s National Parks are rich with cultural history, flora, fauna and some of nature’s most impressive landscapes. As climate change continues to accelerate, these parks and their cultural and natural resources are being threatened. In this project, I will present a colorful, informational booklet that concentrates on 4 specific parks: Yellowstone National Park, National Park of American Samoa, Glacier Bay National Park and Mesa Verde National Park. I will focus on the archaeology and cultural significance of these parks, while also examining the ways that climate change is putting these, and other associated assets of the parks, at risk. I …

A Study Of Marine Terrace Formation Along The California Central Coast, Mary C. Devlin

Natural Resources Management and Environmental Sciences

Marine terrace formation is in many instances attributed to wave action, and shore platforms are often called “wave-cut”. However, alternative models for marine terrace formation suggest that other types of physical and chemical weathering have a more central role in the formation of marine terraces than is widely acknowledged. Roering and Retallack (2012) concluded that the roles of subaerial physical and chemical weathering are significant, and played a major role in the formation of the terraces. In this study, weathering of beach cliffs and shore platforms associated with marine terraces at eight sites in two different locations along the central …

Holocene Glacial Activity In Barilari Bay, West Antarctic Peninsula, Tracked By Magnetic Mineral Assemblages: Linking Ice, Ocean, And Atmosphere, Brendan Reilly, Carl Natter, Stefanie A. Brachfeld

Department of Earth and Environmental Studies Faculty Scholarship and Creative Works

We investigate the origin and fate of lithogenic sediments using magnetic mineral assemblages in Barilari Bay, west Antarctic Peninsula (AP) from sediment cores recovered during the Larsen Ice Shelf System, Antarctica (LARISSA) NBP10-01 cruise. To quantify and reconstruct Holocene changes in covarying magnetic mineral assemblages, we adopt an unsupervised mathematical unmixing strategy and apply it to measurements of magnetic susceptibility as a function of increasing temperature. Comparisons of the unmixed end-members with magnetic observations of northwestern AP bedrock and the spatial distribution of magnetic mineral assemblages within the fjord, allow us to identify source regions, including signatures for ‘‘inner bay,’’ …

A Pilot Study For Examining Population Movement During The Peri-Medieval Climatic Anomaly In The Nebraska Sand Hills, Nora C. Greiman

Department of Anthropology: Theses and Student Research

The Sand Hills of Nebraska comprise a dynamic environment of sand dunes that has changed much over the millennia since their formation. Periods of dune reactivation have occurred throughout history, including one such period at approximately A.D. 900-1300 associated with the Medieval Climatic Anomaly (MCA). Much is known about the geologic activity during this period but little is known about how human populations responded to changing environments. I examine the chronology of three sites occupied during the peri-MCA and the change or stasis in population movements via chemical characterization of ceramic artifacts. Optically stimulated luminescence (OSL) dating was performed on …

Fish Assemblage Structure, Distribution, And Trophic Ecology At Northwestern Gulf Of Mexico Banks, Todd Langland

LSU Doctoral Dissertations

The northwest Gulf of Mexico (Gulf) shelf-edge banks both provide unique hard bottom habitat and support the northernmost coral reefs on the North American continental shelf in a region that is generally characterized by low relief, soft sediments. The habitat value of many of these banks has led to their designation as Habitat Areas of Particular Concern (HAPC) and the Flower Garden Banks National Marine Sanctuary (FGBNMS). However, little is known about the fisheries resources and dynamics of the banks outside the FGBNMS. This study had three main objectives: 1) define reef fish assemblages at northwestern Gulf shelf-edge banks and …

Dust And Pleistocene Ice Ages: Eolian Sediments And Climate Change At Ziegler Reservoir, Snowmass Village, Colorado, Jeffrey S. Honke

Electronic Theses and Dissertations

The discovery of the Ziegler Reservoir fossil site near Snowmass Village, Colorado presents an opportunity to examine subalpine ecosystem response, during a relatively unknown period, in which climate conditions were similar to present. Finegrained sediments at Ziegler Reservoir represent continuous deposition between ~140–55 ka (thousand years before present), spanning the close of the Bull Lake glacial period [marine isotope stage (MIS) 6], the Sangamon interglacial (MIS 5) and the early stages of the Pinedale (early Wisconsin) glacial period (MIS 4). Ziegler Reservoir is positioned on top of a ridge, at an elevation of 2705 m, and has a small watershed …

Small-Scale Mapping Of Indeterminate Arborescent Acroporid Coral (Acropora Cervicornis) Patches, Brian K. Walker, E. A. Larson, Alison L. Moulding, David S. Gilliam

Marine & Environmental Sciences Faculty Articles

Western Atlantic populations of the staghorn coral Acropora cervicornis have drastically declined over the past few decades. Hence, interest in its ecology and spatial extent has increased. Acroporid corals with indeterminate arborescent growth like A.cervicornis primarily reproduce asexually by fragmentation, which can lead to extensive monotypic patches. Since fragmentation is a major component in indeterminate acroporid reproduction, these patches may expand or move over time. Periodic perimeter mapping facilitates comparison of patch areas to determine movement or expansion. A repeatable, low-cost method using a differential GPS carried by a snorkeler was employed to map the perimeter of A.cervicornis …

Spatial Analyses Of Benthic Habitats To Define Coral Reef Ecosystem Regions And Potential Biogeographic Boundaries Along A Latitudinal Gradient, Brian K. Walker

Marine & Environmental Sciences Faculty Articles

Marine organism diversity typically attenuates latitudinally from tropical to colder climate regimes. Since the distribution of many marine species relates to certain habitats and depth regimes, mapping data provide valuable information in the absence of detailed ecological data that can be used to identify and spatially quantify smaller scale (10 s km) coral reef ecosystem regions and potential physical biogeographic barriers. This study focused on the southeast Florida coast due to a recognized, but understudied, tropical to subtropical biogeographic gradient. GIS spatial analyses were conducted on recent, accurate, shallow-water (0–30 m) benthic habitat maps to identify and quantify specific regions …

Hydrostratigraphic Interpretation Of Test-Hole And Surface Geophysical Data, Elkhorn And Loup River Basins, Nebraska, 2008 To 2011, Christopher M. Hobza, Paul A. Bedrosian, Benjamin R. Bloss

United States Geological Survey: Water Reports and Publications

The Elkhorn-Loup Model (ELM) was begun in 2006 to understand the effect of various groundwater-management scenarios on surface-water resources. During phase one of the ELM study, a lack of subsurface geological information was identified as a data gap. Test holes drilled to the base of the aquifer in the ELM study area are spaced as much as 25 miles apart, especially in areas of the western Sand Hills. Given the variable character of the hydrostratigraphic units that compose the High Plains aquifer system, substantial variation in aquifer thickness and characteristics can exist between test holes. To improve the hydrogeologic understanding …

Hyperspectral-Based Adaptive Matched Filter Detector Error As A Function Of Atmospheric Profile Estimation, Allan W. Yarbrough

Theses and Dissertations

Hyperspectral imagery is collected as radiance data. This data is a function of multiple variables: the radiation profile of the light source, the reflectance of the target, and the absorption and scattering profile of the medium through which the radiation travels as it reflects off the target and reaches the imager. Accurate target detection requires that the collected image matches as closely as possible the known "true" target in the classification database. Therefore, the effect of the radiation source and the atmosphere must be removed before detection is attempted. While the spectrum of solar light is relatively stable, the effect …

Hydrostratigraphic Interpretation Of Test-Hole And Geophysical Data, Upper Loup River Basin, Nebraska, 2008-10, Christopher M. Hobza, Theodore H. Asch, Paul A. Bedrosian

United States Geological Survey: Water Reports and Publications

Nebraska's Upper Loup Natural Resources District is currently (2011) participating in the Elkhorn-Loup Model to understand the effect of various groundwater-management scenarios on surface-water resources. During Phase 1 of the Elkhorn-Loup Model, a lack of subsurface geological information in the Upper Loup Natural Resources District, hereafter referred to as the upper Loup study area, was identified as a gap in current knowledge that needed to be addressed. To improve the understanding of the hydrogeology of the upper Loup study area, the United States Geological Survey, in cooperation with the Upper Loup Natural Resources District and the University of Nebraska Conservation …

Geological Analysis And Hydrodynamic Modeling Of Tropical Cyclone Influence: Northeastern Gulf Of Mexico Inner Shelf, Amy Lynn Spaziani

LSU Master's Theses

The need to characterize offshore resources as borrow areas for beach restoration has initiated interest of the impact of storms to the inner continental shelf. While numerous studies have investigated the response of coastal systems to major storms, very little is known about the geological response of inner shelves to frequent and intense storms. This approach integrated a geological study with modeling of hydrodynamics during recent storms, in order to relate trends in the geological signature to physical forcing mechanisms during storms. First, waves and hydrodynamic conditions were modeled during two major recent storms that made landfall in the northeastern …

Extraction And Analysis Of Coral Reef Core Samples From Broward County, Florida., Anastasios Stathakopoulos

HCNSO Student Theses and Dissertations

The reefs off Broward County exist as three shore-parallel, sequentially deeper terraces named the "inner", "middle", and "outer" reefs and also a shallower, nearshore ridge complex. These structures span the continental coast of southeast Florida from Palm Beach County to southern Miami-Dade County and were characterized as relict, early Holocene shelf-edge and mid-shelf reefs along with limestone ridges. Presently, the reefs are colonized by a fauna characteristic of West Atlantic/Caribbean reef systems. Scleractinian coral cover is low except for a few dense patches of Acropora cervicornis, while Acropora palmata is absent except for a few individual living colonies.

Coral …

The Mayan Ice Cap: Glacial Geology And Paleoclimate Of The Northern Guatemalan Highlands, Alex Joseph Roy

UNLV Theses, Dissertations, Professional Papers, and Capstones

The Sierra de los Cuchumatanes region of the northern Guatemalan highlands supported a large plateau ice cap with an area of -40 km2 along with a group of 5 cirque glaciers -1 to 2 km2 during the local last glacial maximum (LLGM). A comprehensive mapping reconstruction of the northern Guatemalan highlands is presented here, including glacial geology and an estimate of maximum ice limits from physical evidence and computer modeling. The glacial geologic map was produced via field mapping with global positioning system (GPS) surveying combined with aerial stereo photographic and topographic map analysis. This new field work on moraine …

Metcrax 2006 - Meteorological Experiments In Arizona's Meteor Crater, C. David Whiteman, Sebastian Hoch, Maura Hahnenberger, Andreas Muschinski, Vincent Hohreiter, Mario Behn, Yonghum Cheon, Sharon Zhong, Wenqing Yao, David Fritts, Craig Clements, Thomas Horst, William Brown, Steven Oncley

Faculty Publications, Meteorology and Climate Science

The Meteor Crater Experiment (METCRAX 2006) was conducted in October 2006 at Arizona's Meteor Crater to investigate stable boundary layer evolution in a topographically uncomplicated basin surrounded by the nearly homogeneous plain of the Colorado Plateau. The two goals of the experiment were 1) to investigate the microscale and mesoscale structure and evolution of the stable boundary layer in the crater and its surroundings and 2) to determine whether atmospheric seiches or standing waves are produced inside the crater. This article provides an overview of the scientific goals of the experiment; summarizes the research measurements, the crater topography, and the …

Sediment Flux And Fate In The Mississippi River Diversion At West Bay: Observation Study, Thomas Mitchell Andrus

LSU Master's Theses

Land-building sediment diversions, such as the Mississippi River Diversion at West Bay, can be used as important building blocks in the conservation and restoration of Mississippi Delta wetlands. Sediment deposition and retention patterns were studied in the West Bay diversion outfall area through analyses of sediment cores, hydrodynamics, and bathymetry. Cores and x-ray samples were collected at twenty stations in March 2004, August 2004, November 2005, and April 2006. Cores were analyzed for grain-size distributions and ⁷Be activities, in order to examine patterns of recent sediment deposition. In comparing ratios of total ⁷Be inventory to atmospheric ⁷Be …

Visualizing The Geology Of Lake Trout Spawning Sites: Northern Lake Michigan, Peter Dartnell, Peter Barnes, James V. Gardner, Kristen Lee

Center for Coastal and Ocean Mapping

Geologists and biologists are working together to understand the links between lake floor geology (composition and shape) and the distribution of lake trout throughout their life cycle. Lake floor geology is one of the main factors determining where lake trout spawn, feed, and hide. In support of ongoing research to study Lake Michigan trout habitats, the U.S. Geological Survey in cooperation with the U.S. Army Corps of Engineers mapped the morphology of principle lake trout spawning sites. Using the Army Corps of Engineer's SHOALS airborne lidar (Light Detection and Ranging) system we mapped six regions in Northern Lake Michigan in …

Automatic Processing Of High-Rate, High-Density Multibeam Echosounder Data, Brian R. Calder, Larry A. Mayer

Center for Coastal and Ocean Mapping

Multibeam echosounders (MBES) are currently the best way to determine the bathymetry of large regions of the seabed with high accuracy. They are becoming the standard instrument for hydrographic surveying and are also used in geological studies, mineral exploration and scientific investigation of the earth's crustal deformations and life cycle. The significantly increased data density provided by an MBES has significant advantages in accurately delineating the morphology of the seabed, but comes with the attendant disadvantage of having to handle and process a much greater volume of data. Current data processing approaches typically involve (computer aided) human inspection of all …

Status Of Coral Reefs Of Little Cayman, Grand Cayman And Cayman Brac, British West Indies, In 1999 And 2000 (Part 1: Stony Corals And Algae), Carrie Manfrino, Bernhard Riegl, Jerome L. Hall, Robert Graifman

Marine & Environmental Sciences Faculty Articles

A benthic assessment of the isolated Cayman Islands was completed at 42 sites. Major changes in the reef community structure were documented by comparison with earlier studies. Acropora palmata and A. cervicornis, once abundant as shallow framework builders, were uncommon. Diseased stony corals were seen in >90% of the study sites, with the highest averages in Little Cayman, especially at Bloody Bay which is one of the most highly regulated marine parks in the Cayman Islands. The Montastraea annularis species complex accounted for two-thirds of the diseased corals which, along with other massive species, were affected largely by white-plague …

Benthic Community Analysis Of Hog Island Bay, Virginia, David James Lewis

Biological Sciences Theses & Dissertations

The benthic infaunal macroinvertebrate communities of Hog Island Bay of the Virginia Eastern Shore were quantitatively sampled at 30 locations on August 31 and September 1, 1995. The primary objectives of this study were: (1) to characterize the subtidal macroinfaunal benthic communities of Hog Island Bay, (2) to examine relationships between abiotic factors and the macroinfaunal communities and (3) to characterize the environmental condition of the system using the Benthic Index of Biotic Integrity (B-IBI) (Weisburg et al. 1997) and the EMAP Benthic Index for the Virginian Province (Strobel et al. 1995).

The ecological condition of Hog Island Bay appears …

An Evaluation Of Methods For Identifying And Interpreting Buried Soils In Late Quaternary Loess In Alaska, Daniel R. Muhs, Thomas A. Ager, Josh M. Been, Joseph G. Rosenbaum, Richard L. Reynolds

United States Geological Survey: Staff Publications

The presence of buried soils in Alaskan loess is controversial, and therefore criteria for identifying buried soils in these deposits need to be evaluated. In this paper, morphologic and chemical criteria for identifying buried soils are evaluated by studying modern soils developed mostly in Holocene loess under tundra, boreal forest, and transitional coastal-boreal forest vegetation in different parts of Alaska. Data from modern Alaskan soils that developed under vegetation similar to that of the present indicate that soil morphology, organic-matter concentrations, and P concentrations can be useful diagnostic tools for identifying buried soils. Soil morphologic criteria, particularly horizon colors and …

The Role Played By Semisubmersible Exploratory Drilling Platforms As A Vector In Marine Biological Introductions, Sean S. Bercaw

Marine Affairs Theses and Major Papers

Through discussion of Semisubmersible Exploratory Drilling Platforms and their role as vectors in marine biological introductions, this paper establishes a base of knowledge for future referral. Included in this project are details of semisubmersibles, their unique characteristics and operations, historical movements, past introductions, future operations, and continuing potential for invasions. The significance of semisubmersibles as biological vectors is further addressed. Three criteria will be used to assess the significance of the role of semisubmersibles in the introduction of alien species: first, what is the rate of SEDP movements over time; second, how are SEDP movements unique, and what role does …

Distribution Of Foraminifera And Pollen In Coastal Depositional Environments Of The Southern Delmarva Peninsula, Virginia, U.S.A., Han Jun Woo

OES Theses and Dissertations

The coastal zone of the southern Delmarva Peninsula exhibits a wide variety of barrier island system subenvironments. This study investigates whether 20 a priori subenvironments can be distinguished from each other on the basis of abiotic environmental variables, pollen assemblages, living foraminiferal populations, and total (living plus dead) foraminiferal assemblages.

The physical data collected from the coastal zone were subjected to canonical variate analysis which discriminated 83% of the stations in 19 groups. These groups were clustered into two internally overlapping sets which represented the inside and outside of the inlet.

Twenty-two pollen types were found in low-energy marsh and …