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Articles 91 - 120 of 130

Full-Text Articles in Geology

Gravitational Study Of The Hastings Salt Dome And Associated Faults In Brazoria And Galveston Counties,Texas, Francis C. Okocha May 2017

Gravitational Study Of The Hastings Salt Dome And Associated Faults In Brazoria And Galveston Counties,Texas, Francis C. Okocha

Electronic Theses and Dissertations

Salt domes are important geological structures because they are potential major hydrocarbon traps and have a profound effect on overlying strata in the subsurface. Over five hundred salt domes have been located on the United States Gulf Coast region, including the Hastings Salt Dome. Hastings Oil Field is located about 40.2 km (25 miles) southeast of Houston, Texas. The Hasting oil field was discovered in 1934 and it was considered the largest oil reserve on the Gulf Coast. Its peak production of 75,000 BOPD (barrels of oil per day) was recorded in 1977 and it had a cumulative production of …


Structural And Stratigraphic Reconstruction Of The Whiting Dome Salt Structure In Viosca Knoll-Mississippi Canyon, Gom, Using 3d Seismic Data, Matthew R. Worrell May 2017

Structural And Stratigraphic Reconstruction Of The Whiting Dome Salt Structure In Viosca Knoll-Mississippi Canyon, Gom, Using 3d Seismic Data, Matthew R. Worrell

Electronic Theses and Dissertations

Understanding the complexities of salt tectonics is one of the most important factors regarding seismic interpretation of stratigraphy, structure, and geomorphology in the Gulf of Mexico. Evaluating the processes affecting recent mobilization of salt in the shallow, well-imaged section can help provide analogues for older, similar occurrences in the deeper section, thereby providing structural models for the autochthonous salt and its effect on stratigraphy and even potential timing and migration issues of hydrocarbons.

Progradation of delta front and shelf to slope transitional sediments has expulsed and emplaced an allochthonous salt structure (Whiting Dome) in the Viosca Knoll and Mississippi Canyon …


Basement And Cover Structural Analysis Along The Eagle River Gorge, Sawatch Range, Colorado, Kaitlin Lee Askelson May 2017

Basement And Cover Structural Analysis Along The Eagle River Gorge, Sawatch Range, Colorado, Kaitlin Lee Askelson

Electronic Theses and Dissertations

The Sawatch Range within the Rocky Mountains of central Colorado exposes Paleoproterozoic basement and overlying Paleozoic sedimentary rocks with a complex history of ductile and brittle deformation.

The goal of this study is to conduct analyses of brittle structures that occur in the basement and cover units to determine geometric relationships between the structures, provide a detailed description of structures and refine a geologic history for structures along the basement-cover contact in the northeastern Sawatch Range along the Eagle River canyon and U.S. Highway 24 from Red Cliff to Gilman, Colorado. Paleoproterozoic basement rocks include the Cross Creek granite, diorites, …


The Tuscaloosa Marine Shale: Geologic History, Depositional Analysis, And Exploration Potential, Jessica D. Pair Feb 2017

The Tuscaloosa Marine Shale: Geologic History, Depositional Analysis, And Exploration Potential, Jessica D. Pair

Electronic Theses and Dissertations

The Tuscaloosa Marine Shale (TMS) was deposited across southern Louisiana and Mississippi during the Upper Cretaceous. The study focuses on a core region containing vast deposits of Cretaceous-aged sediments that have economic importance for oil and gas exploration. This region has been conventionally drilled for decades, focusing on the recovery of the Cretaceous hydrocarbons. Explorers within this region had traditionally targeted the massive sand units of the Lower and Upper Tuscaloosa Group while neglecting the middle Tuscaloosa Marine Shale unit. With the onset of unconventional drilling technology, new explorers to the region have begun to delineate the Tuscaloosa Marine Shale’s …


Re-Evaluating The Tectonic Model For The Arbuckle Mountains, Oklahoma By Spatial And Geometric Analysis Of Stratigraphic And Structural Trends, Dakota James Kolb Jan 2017

Re-Evaluating The Tectonic Model For The Arbuckle Mountains, Oklahoma By Spatial And Geometric Analysis Of Stratigraphic And Structural Trends, Dakota James Kolb

Electronic Theses and Dissertations

Understanding the spatial distribution and geometric relations between stratigraphy and structural features can allow for a more accurate tectonic timeline to be considered for not only the Arbuckle Mountains but for the assembly of modern North America. The Arbuckle Mountains in south central Oklahoma exhibit structurally complex stratigraphy associated with regional features like the Southern Oklahoma Aulacogen, the Arbuckle Anticline and the Washita Valley fault. Camp Classen YMCA and Turner Falls city park in Davis, OK, hosts observed, but largely unmapped, small scale structural features that best represent the magnitude of deformation. The goal of this study was to determine …


Co2 Adsorption On Volcanic Ash: Net Contribution Of Volcanic Eruptions To The Global Carbon Cycle, Lee New Jan 2017

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 Jan 2017

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 …


Carbon Cycle Trends Recorded By Organic Carbon Stable Isotopes In Paleocene Strata, Benton County, Mississippi: Implications For Chronostratigraphy Of The Porters Creek And Naheola Formations, Erica Gerweck Jan 2017

Carbon Cycle Trends Recorded By Organic Carbon Stable Isotopes In Paleocene Strata, Benton County, Mississippi: Implications For Chronostratigraphy Of The Porters Creek And Naheola Formations, Erica Gerweck

Electronic Theses and Dissertations

The paleocene-eocene thermal maximum (petm) is one of the most studied carbon isotope excursions in earth's history. The petm occurred 55 million years ago when excess isotopically heavy carbon (c13) was added into earth's carbon cycle, resulting in ecological and environmental changes. The petm is marked by a negative stable carbon isotope excursion (cie) in marine and continental strata around the globe. The paleocene and eocene boundary is contained in the sedimentary fill of the Mississippi embayment so there is high potential to produce new petm stable isotope datasets. The purpose of this project is to analyze the boundary for …


Paleodrainage Insights Into The Fluvial And Glacial History Of The Western Chukchi Margin, Arctic Alaska, Brittany A. Stockmaster Jan 2017

Paleodrainage Insights Into The Fluvial And Glacial History Of The Western Chukchi Margin, Arctic Alaska, Brittany A. Stockmaster

Electronic Theses and Dissertations

Chirp subbottom data collected from the Chukchi shelf, offshore of northwest Alaska, revealed extensive paleodrainage networks that incised the margin during sea level lowstands. These features are cut into folded Cretaceous bedrock strata and represent multiple sea level cycles. Several large incised valleys, 10s of km wide and up to 54 m deep, as well as numerous smaller, individual channels were identified. Sources of fluvial input include several, smaller rivers on the northwest Alaskan coast, such as the Kokolik, Kuk, Kukpowruk, and the Utukok Rivers. Correlation of sediment infill patterns provided insight to paleochannels and paleovalleys as well as outlined …


Geologic And Geochemical Characterization Of Cross-Communication Potential Within The Northern Edwards Aquifer System, Texas, Ingrid J. Eckhoff Dec 2016

Geologic And Geochemical Characterization Of Cross-Communication Potential Within The Northern Edwards Aquifer System, Texas, Ingrid J. Eckhoff

Electronic Theses and Dissertations

The Edwards Aquifer is a large, complex groundwater system located throughout Central Texas in association with the Balcones Fault Zone. The San Antonio and Barton Spring segments of the Edwards Aquifer have been extensively studied in the past because they provide groundwater resources to the largely urbanized areas of San Antonio and Austin, respectively, and smaller communities along the Interstate 35 corridor. Previous research has been conducted on these southern and central portions of the Edwards Aquifer system, which have characterized the structural, hydrogeological and geochemical variations within the highly karsted region. However, the Northern Segment of the Edwards Aquifer …


Geotechnical Properties Of The Travis Peak (Hosston) Formation In East Texas: A Compressive And Tensile Strength Analysis Using Regression Analysis., Pawan Kakarla Dec 2016

Geotechnical Properties Of The Travis Peak (Hosston) Formation In East Texas: A Compressive And Tensile Strength Analysis Using Regression Analysis., Pawan Kakarla

Electronic Theses and Dissertations

The estimation of rock mass strength is a key parameter in geotechnical engineering which is used in the design of geotechnical structures like tunnels, dams and slopes. Geotechnical engineering is the branch of civil engineering which works on the principles of soil and rock mechanics to evaluate subsurface conditions, stability of slopes, foundations of structures and construction of earthworks. The main focus of this study was to calculate the strength of Lower Cretaceous Travis Peak Formation rocks of East Texas and to check the accuracy by comparing it with Regression analysis. The parameters which were used were the Uniaxial Compression …


Characterization And Delineation Of Karst Geohazards Along Rm652 Using Electrical Resistivity Tomography, Culberson County, Texas, Adam F. Majzoub Dec 2016

Characterization And Delineation Of Karst Geohazards Along Rm652 Using Electrical Resistivity Tomography, Culberson County, Texas, Adam F. Majzoub

Electronic Theses and Dissertations

The Delaware Basin of West Texas and southeastern New Mexico is the major western subdivision of the Permian Basin and a northern extension of the Chihuahuan Desert. The major evaporite unit within the Delaware Basin is the Castile Formation, which consists of gypsum/anhydrite and is highly susceptible to dissolution and karsting. Manifestations of karst within the Castile outcrop are abundant and include sinkholes, subsidence features and caves, both epigene and hypogene in origin.

Land reconnaissance surveys conducted during the summer of 2015 documented abundant karst landforms in close proximity to a major thoroughfare, RM 652, in Culberson County, Texas. 2D …


Speleogenesis And Delineation Of Megaporosity And Karst Geohazards Through Geologic Cave Mapping And Lidar Analyses Associated With Infrastructure In Culberson County, Texas, Jon T. Ehrhart Dec 2016

Speleogenesis And Delineation Of Megaporosity And Karst Geohazards Through Geologic Cave Mapping And Lidar Analyses Associated With Infrastructure In Culberson County, Texas, Jon T. Ehrhart

Electronic Theses and Dissertations

The Gypsum Plain region of the Delaware Basin hosts approximately 1800 km2 of the Castile Formation outcrop. A myriad of karstic developments from closed sinkholes to large multi-kilometer cave systems have been documented within the region. Karst studies on the distribution and speleogenetic evolution within Castile strata began within the last decade with ever increasing data resolution. In this study, a combination of both physical field surveys and analyses of high resolution (~30 cm accuracy) LiDAR data was used to create a theoretical model for karst development across the region. This idealized model considers speleogenetic formation type variations (hypogene …


Cone In Cone Concretions Of The Stanley Group In Southeastern Oklahoma, Kyle B. Ayres May 2016

Cone In Cone Concretions Of The Stanley Group In Southeastern Oklahoma, Kyle B. Ayres

Electronic Theses and Dissertations

Cone in cone concretions found in the Stanley Group of Southeastern Oklahoma have a variety of external and internal attributes which allow diagenetic and theoretical models of formation to be hypothesized. Stanley Group carbonate cone in cone concretions are initially formed in sulfur reducing horizons at shallow burial depths in a poorly circulated possibly deep trough containing siliceous sediments and organic matter. Collected concretions near the town of Smithville, Oklahoma displayed four different external morphologies and four variations of mineral constituents. All concretions contained microscopic cones which initiated diffusion and/or fluid patterns and is an early cementation process that directly …


Characterization Of Lower Permian Carbonate Subaqueous Gravity Flows In Crockett County, Texas, Wesley L. Turner May 2016

Characterization Of Lower Permian Carbonate Subaqueous Gravity Flows In Crockett County, Texas, Wesley L. Turner

Electronic Theses and Dissertations

Transitional sediments on carbonate ramp slopes act as a link to relatively well-studied platform and basin depositional environments. In the southern Midland Basin, the key to understanding the relationship between these environments lies in the allochthonous gravity flow sediments found on the slope. Here, a succession of various gravity flow deposits is used to interpret how base level fluctuations affect the type of deposits found on the slope and their effect on the deep basinal environment. This study utilizes core samples from the Wolfcamp Formation adjacent to the Central Basin Platform in five wells in Northwest Crockett County, Texas. The …


An Investigation Of Hydrogeologic, Stratigraphic, And Structural Controls On Acer Grandidentatum Communities In A Karst Landscape, Owl Mountain Province, Fort Hood Military Installation, Texas, Melinda S. Faulkner May 2016

An Investigation Of Hydrogeologic, Stratigraphic, And Structural Controls On Acer Grandidentatum Communities In A Karst Landscape, Owl Mountain Province, Fort Hood Military Installation, Texas, Melinda S. Faulkner

Electronic Theses and Dissertations

The Owl Mountain Province is located within the Fort Hood Military Installation, an approximately 880 km2 installation established in the 1940s in Bell and Coryell counties, Texas, which has undergone extensive land use changes associated with military training, maintaining much of the vegetation in early succession. This study investigates thelithologic, stratigraphic, and structural controls on the hydrologic, hydrogeologic, and geomorphologic evolution of the Owl Mountain Province as expressed by mesic vegetation communities, including Pleistocene relicts Acer grandidentatum, within karst terrains. These systems exhibit complexly overprinted speleogenetic evolutions within a dynamic groundwater regime resulting from regional climate shifts throughout the …


Speleogenesis Of Critchfield Bat Caves And Associated Hydrogeology Of The Northern Edwards Aquifer, Williamson County, Texas, Ashley N. Landers May 2016

Speleogenesis Of Critchfield Bat Caves And Associated Hydrogeology Of The Northern Edwards Aquifer, Williamson County, Texas, Ashley N. Landers

Electronic Theses and Dissertations

Karst development in the Edwards Aquifer has been significantly studied in the San Antonio and Barton Spring Segments; however, karst development remains poorly studied in the Northern Segment. Detailed characterization of the Northern Segment is vital for future water conservation because of increasing urban sprawl along the Interstate 35 corridor. The Northern Segment of the Edwards Aquifer consists of Lower Cretaceous strata of the Comanche Peak, Edwards, and Georgetown formations. The stratigraphy is dominated by Edwards Limestone as it is the only formation that crops out in the study area.

Karst, stratigraphic, GIS, and geochemical studies were conducted to evaluate …


The Stratigraphic Position Of Fossil Vertebrates From The Pojoaque Member Of The Tesuque Formation (Middle Miocene, Late Barstovian) Near Española, New Mexico, Garrett R. Williamson May 2016

The Stratigraphic Position Of Fossil Vertebrates From The Pojoaque Member Of The Tesuque Formation (Middle Miocene, Late Barstovian) Near Española, New Mexico, Garrett R. Williamson

Electronic Theses and Dissertations

The stratigraphy of the Pojoaque Member of the Tesuque Formation near Española, NM is not well understood. This region, during the Middle Miocene, represented a dynamic alluvial fan-fluvial-lacustrine environment within the Española Basin while the Rio Grande Rift was active. Cavazza (1986) identified two paleodrainage systems (lithosome A, basin-margin facies and B, basin-floor facies) by means of sandstone and conglomerate petrology, paleocurrent, and sedimentary facies analyses. After x-ray diffraction analyses of claystones within lithosome B, mordenite was discovered, which is a zeolite mineral commonly found within volcanic rocks. This is significant because the presence of mordenite confirms Cavazza’s (1986) conclusion …


Ecological Niche Modeling Of The North American Giant Salamander: Predicting Current And Future Potential Distributions And Examining Environmental Influences, Selena S. Roark May 2016

Ecological Niche Modeling Of The North American Giant Salamander: Predicting Current And Future Potential Distributions And Examining Environmental Influences, Selena S. Roark

Electronic Theses and Dissertations

North American Giant Salamanders (Cryptobranchus alleganiensis), commonly known as hellbenders, have been experiencing a population decline for decades due to human influences, such as pollution and habitat destruction. Many efforts are underway to save the hellbender but their entire potential geographical range has not been well-studied. Currently, hellbender populations are delineated by county boundaries and are on the International Union for Conservation of Nature Red List. The Genetic Algorithm for Rule-set Production, an Ecological Niche Model, was used to model the current hellbender potential distribution at a macro-scale under two different environmental scenarios. Additionally, future potential distributions were …


New Records Of Colubrids From The Late Hemphillian Gray Fossil Site Of Northeastern Tennessee, Derek J. Jurestovsky May 2016

New Records Of Colubrids From The Late Hemphillian Gray Fossil Site Of Northeastern Tennessee, Derek J. Jurestovsky

Electronic Theses and Dissertations

The Gray Fossil Site is a rich Hemphillian (North American Land Mammal Age) locality located in northeastern Tennessee which has produced tens-of-thousands of fossils of multiple taxa including hundreds of individual snake skeletal remains. Analyzed here are cranial and vertebral fossils identified as belonging to various colubrid taxa including Carphophis sp., Gyalopion sp., Heterodon sp., Natricinae indeterminate, Thamnophis sp., and a new, undescribed genus and species. In addition, multiple new features of snake vertebrae are described, some of which question the validity of the genus Neonatrix. Finally, the distribution and paleoecology of the listed genera allows an interpretation of …


Evaluation Of Groundwater Quality In Paleozoic Aquifers Using Gis Techniques, Central Texas, Garrett R. Harris Apr 2016

Evaluation Of Groundwater Quality In Paleozoic Aquifers Using Gis Techniques, Central Texas, Garrett R. Harris

Electronic Theses and Dissertations

Lab analyses of groundwater chemistry from monitoring wells completed in the Paleozoic Aquifers surrounding the Llano Uplift of Central Texas has been recorded and made available to the public through the Texas Water Development Board (TWDB). This study evaluated the results of these data dating back to the 1940s to determine changes over time, the dynamics of the hydrologic system, and the locations where hydraulic connectivity is most probable. The initial results established two distinct hydrologic systems that required the separation of the northern from the southern region. The northern sub-region (NSR) contains the largest expanse of continuity of both …


The Porosity And Permeability Distribution Of The Shoal Grainstone And Thrombolitic Facies Of The Smackover Formation In Little Cedar Creek And Brooklyn Fields In Southwestern Alabama, Devin Thomas Jan 2016

The Porosity And Permeability Distribution Of The Shoal Grainstone And Thrombolitic Facies Of The Smackover Formation In Little Cedar Creek And Brooklyn Fields In Southwestern Alabama, Devin Thomas

Electronic Theses and Dissertations

The Smackover Formation is the most prolific hydrocarbon producer in Alabama, with the Little Cedar Creek and Brooklyn Fields being the two largest producers in Alabama. Unlike other Smackover fields Little Cedar Creek Field and Brooklyn Field production is the result of two reservoirs, known as the shoal grainstone and thrombolite (microbial) boundstone. Even with the success of the Smackover Formation, geographic trends of the porosity and permeability are problematic because production is affected. The distribution of the facies also plays a role in the porosity and permeability. The objective of this study is to delineate porosity and permeability trends …


Cyclostratigraphy And Sedimentation Of The Cenomanian-Turonian Tuscaloosa Marine Shale, Christian Gilbert Kunhardt Jan 2016

Cyclostratigraphy And Sedimentation Of The Cenomanian-Turonian Tuscaloosa Marine Shale, Christian Gilbert Kunhardt

Electronic Theses and Dissertations

A cyclostratigraphic and geochemical analysis was conducted on the basal high resistivity zone of the Tuscaloosa Marine Shale to determine if orbital forcing is apparent in mineralogical data suites. Geochemical data suites obtained via x-ray diffraction from five cored wells located near the southern Mississippi/Louisiana border were used in the study. The results were used in concert with previously published insolation and biostratigraphic data and unpublished stable carbon isotope data to determine sedimentation rate, to identify and correlate the cretaceous oceanic anoxic event 2 (OAE 2) recovery period within the studied interval, and to determine the possible mechanisms of orbital …


Using Kriging, Cokriging, And Gis To Visualize Fe And Mn In Groundwater, Crystal Johnson May 2015

Using Kriging, Cokriging, And Gis To Visualize Fe And Mn In Groundwater, Crystal Johnson

Electronic Theses and Dissertations

For aesthetic, economic, and health-related reasons, allowable concentrations of iron (Fe) and manganese (Mn) found present in drinking water are 0.3 mg/L and 0.05 mg/L, respectively. Water samples taken from private drinking wells in the rural communities within Buncombe County, North Carolina contain amounts of these metals in concentrations higher than the suggested limits. This study focused on bedrock geology, elevation, saprolite thickness, and well depth to determine factors affecting Fe and Mn. Using ArcGIS 10.2, spatial trends in Fe and Mn concentrations ranges were visualized, and estimates of the metal concentrations were interpolated to unmonitored areas. Results from this …


Using Geometric Morphometrics To Differentiate Lower First Molars Of Microtus Species: A Review Of The Clark’S Cave Bone Deposit, Va, Mark Shelleman May 2015

Using Geometric Morphometrics To Differentiate Lower First Molars Of Microtus Species: A Review Of The Clark’S Cave Bone Deposit, Va, Mark Shelleman

Electronic Theses and Dissertations

Clark’s Cave contains a large collection of late Pleistocene mammal material. In particular, it contains a sizable amount of Microtus spp. which can be valuable paleoclimate indicators. Identification techniques traditionally used to classify these species have been shown to be unreliable. Recent studies have shown that using geometric morphometric techniques on lower first molars can be more successful. By placing landmarks and running a discriminate analysis on new and previously collected material from the cave, significant differences in Microtus species proportions were found. Specifically, showing the deposit has a larger proportion of M. xanthognathus than previously reported; resulting in a …


Microtremor Recordings In Northern Mississippi: Evaluating Site Effect And Correlating With Wave Climate, Zhen Guo Jan 2015

Microtremor Recordings In Northern Mississippi: Evaluating Site Effect And Correlating With Wave Climate, Zhen Guo

Electronic Theses and Dissertations

Site effects is considered as one of the main reasons that cause enormous damages in earthquakes and it is mainly controlled by the local geological condition. The main research area, Northern Mississippi, is located in Mississippi Embayment (ME) where is mainly composed of unconsolidated sediments which can be as thick as 1400m along the Mississippi River floodplain, and is favorable to have significant site effects. Meanwhile Northern Mississippi is also located in the moderate to heavy potential damage area of the New Madrid Seismic Zone, which is in the northern section of ME. Therefore, it is very necessary to evaluate …


Identifying A Mechanism For An Infiltration Threshold From The Sunflower River, Ms To The Underlying Alluvial Aquifer, Austin Cole Patton Jan 2015

Identifying A Mechanism For An Infiltration Threshold From The Sunflower River, Ms To The Underlying Alluvial Aquifer, Austin Cole Patton

Electronic Theses and Dissertations

Long-term groundwater level and stream stage measurements at a USGS coupled groundwater stream-gaging station located on the Sunflower River in Sunflower, MS show an apparent stage-threshold for infiltration to the underlying alluvial aquifer. This site is located near the center of a large regional groundwater cone of depression in the Mississippi River Valley alluvial aquifer. The USGS well (termed well 3 in this study) was thought to be completed in the regional shallow aquifer, though often recording anomalously high water levels relative to other wells in the region. The purpose of this research was to identify the responsible mechanism for …


Dust And Pleistocene Ice Ages: Eolian Sediments And Climate Change At Ziegler Reservoir, Snowmass Village, Colorado, Jeffrey S. Honke Jun 2014

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 …


Continuous Tracking Of Lava Effusion Rate In A Lava Tube At Kilauea Volcano Using Very Low Frequency (Vlf) Monitoring, Richard A. Freeman May 2014

Continuous Tracking Of Lava Effusion Rate In A Lava Tube At Kilauea Volcano Using Very Low Frequency (Vlf) Monitoring, Richard A. Freeman

Electronic Theses and Dissertations

Measurement of lava effusion rates is a key objective for monitoring basaltic eruptions because it helps constrain geophysical models of magma dynamics, conduit geometry, and both deep and shallow volcano processes. During these eruptions, lava frequently travels through a single "master" lava tube. A new method and instrument for continuously monitoring the crosssectional area of lava streams in tubes and estimating the instantaneous effusion rate (IER) is described. The method uses 2 stationary very low frequency (VLF) radio receivers to measure an unperturbed VLF signal and the influence of highly conductive molten lava on that signal. The difference between these …


Analysis Of Snake Creek Burial Cave Mustela Fossils Using Linear & Landmark-Based Morphometrics: Implications For Weasel Classification & Black-Footed Ferret Conservation, Nathaniel S. Fox Iii May 2014

Analysis Of Snake Creek Burial Cave Mustela Fossils Using Linear & Landmark-Based Morphometrics: Implications For Weasel Classification & Black-Footed Ferret Conservation, Nathaniel S. Fox Iii

Electronic Theses and Dissertations

Two discreet methods of geometric morphometrics were applied to evaluate the taxonomic utility of each in classifying the craniomandibular region of several Mustela species. Use of both linear measurements and 2-dimensional landmarks proved successful in discriminating between extant M. nigripes (black-footed ferret) and Neovison vison (American mink), in addition to the extant North American weasel species (M. erminea, M. frenata, M. nivalis). Methods were then used to classify Late Pleistocene Mustela spp. fossils collected from Snake Creek Burial Cave (SCBC) of eastern Nevada. Data acquired for unknown predicted group memberships varied markedly among methods and specimens. …