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Vitis Seeds (Vitaceae) From The Late Neogene Gray Fossil Site, Northeastern Tennessee, Usa., Fade Gong

Electronic Theses and Dissertations

This study focuses on the morphometric and systematic studies of fossil vitaceous seeds recently recovered from the Gray Fossil Site (7-4.5 Ma, latest Miocene-earliest Pliocene) northeastern Tennessee. Morphologically, all fossil seeds correspond to the extant subgenus Vitis (genus Vitis) of the Vitaceae based on the smooth dorsal surface with a centrally positioned chalaza connected with a conspicuous chalaza-apex groove and short linear ventral infolds that are slightly diverged apically. A multivariate analysis based on 11 measured characters from 76 complete seeds identified three types of seeds, each representing a distinct morphotaxon. Based on comparison with modern and fossil vitaceous …

From Decades To Epochs: Spanning The Gap Between Geodesy And Structural Geology Of Active Mountain Belts, Richard W. Allmendinger, John P. Loveless, Matthew E. Pritchard, Brendan Meade

Geosciences: Faculty Publications

Geodetic data from the Global Navigation Satellite System (GNSS), and from satellite interferometric radar (InSAR) are revolutionizing how we look at instantaneous tectonic deformation, but the significance for long-term finite strain in orogenic belts is less clear. We review two different ways of analyzing geodetic data: velocity gradient fields from which one can extract strain, dilatation, and rotation rate, and elastic block modeling, which assumes that deformation is not continuous but occurs primarily on networks of interconnected faults separating quasi-rigid blocks. These methods are complementary: velocity gradients are purely kinematic and yield information about regional deformation; the calculation does not …

Strain Rate Patterns From Dense Gps Networks, Matthias Hackl, Rocco Malservisi, Shimon Wdowinski

School of Geosciences Faculty and Staff Publications

The knowledge of the crustal strain rate tensor provides a description of geodynamic processes such as fault strain accumulation, which is an important parameter for seismic hazard assessment, as well as anthropogenic deformation. In the past two decades, the number of observations and the accuracy of satellite based geodetic measurements like GPS greatly increased, providing measured values of displacements and velocities of points. Here we present a method to obtain the full continuous strain rate tensor from dense GPS networks. The tensorial analysis provides different aspects of deformation, such as the maximum shear strain rate, including its direction, and the …

Archaeometric Comparison Between The Neolithic Pottery Of Different Cultures At The Archaeological Site Of Alba Iulia (Transylvania, Romania), Bruno Fabbri, Mihai Gligor, Sabrina Gualtieri, Simona Varvara

Studia UBB Geologia

A large quantity of pottery has been discovered at the Lumea Nouă Neolithic and Eneolithic settlement in Alba Iulia City (Romania). It belongs to different cultures, and in this paper a comparison among three of them is made: Vinča, Lumea Nouă and Foeni. An analogous number of samples has been selected for each of the three cultures, together with some clay samples collected in the Alba Iulia settlement area. The samples have been analysed by means of XRF, XRPD, and in thin section. Significant differences among the three cultures are only related to the alkalis contents. The Lumea Nouă pottery …

Fore-Arc Motion And Cocos Ridge Collision In Central America, Peter Lafemina, Timothy Dixon, Rob Govers, Edmundo Norabuena, Henry Turner, Armando Saballos, Glen Mattioli, Marino Protti, Wilfried Strauch

School of Geosciences Faculty and Staff Publications

We present the first regional surface velocity field for Central America, showing crustal response to interaction of the Cocos and Caribbean plates. Elastic half-space models for interseismic strain accumulation on the dipping subduction plate boundary fit the GPS data well and show strain accumulation offshore and beneath the Nicoya and Osa peninsulas in Costa Rica but not in Nicaragua. Since large subduction zone earthquakes occur in Nicaragua, we suggest that interseismic locking in Nicaragua and some other parts of Central America occurs but is mainly shallow, depth, too far offshore to be detected by our on-land GPS measurements. Our data …

The Biscayne Aquifer Of Southeastern Florida, Kevin J. Cunningham, Lee J. Florea

Earth, Environmental, and Atmospheric Sciences Faculty Publications

No abstract provided.

The Pecos River Hypogene Speleogenetic Province: A Basin-Scale Karst Paradigm For Eastern New Mexico And West Texas, Usa, Kevin W. Stafford, Alexander Klimchouk, Lewis Land, Marcus O. Gary

Faculty Publications

Since the mid-Tertiary, lateral migration and entrenchment of the Pecos River Valley in eastern New Mexico and west Texas, USA, has significantly influenced regional groundwater flow paths, providing a focus for ascending flow in multi-storey artesian systems and a powerful potentiometric driving force for hypogene speleogenesis. Individual occurrences of hypogene karst phenomena associated with the central Pecos River Valley are widespread throughout the greater Delaware Basin region, including development in a wide range of Permian carbonate and evaporate fades. Hypogene occurrences are well-documented as far north as Santa Rosa, New Mexico and as far south as Lake Amistad, Texas. Throughout …

Resistivity And Conductivity Studies Of The Rattlesnake Springs, New Mexico Watershed, Claudia Santiago

Open Access Theses & Dissertations

Rattlesnake Springs are a high-discharge artesian springs situated in the upper Black River Valley in southwestern Eddy Country, New Mexico. The aquifer that supplies the Rat- tlesnake Springs has been the main water source for domestic use by visitors of Carlsbad Caverns National Park and residents of neighboring ranches since the 1930s. Several ge- ological studies relying on surface geology and limited water wells had previously been conducted in the area to examine the trend of ground water flow. In this study I used con- ductivity and resistivity geophysical techniques to identify possible locations of fractures in the subsurface of …

Using Gis To Quantify Patterns Of Glacial Erosion On Northwest Iceland: Implications For Independent Ice Sheets, Sarah M. Principato, Jeremiah S. Johnson

Environmental Studies Faculty Publications

Glacial erosion patterns on northwest Iccliind are quantified using a Geographic Information System (GIS) in order to interpret subglacial characteristics of part of northwest Iceland affected by ice sheet glaciation. Ice scour lake density is used as a proxy for glacial erosion. Erosion classes are interpreted from variations in the density of lake basins. Lake density was calculated using two dilTerent methods: the first is sensitive to the total number of lakes in a specific area, and the second is sensitive to total lake area in a specific area. Both of these methods result in a value for lake density, …

Geochemistry Of The Middle Miocene Collision-Related Yamadaği ( Eastern Anatolia) Calc-Alkaline Volcanics, Turkey, Taner Eki̇ci̇, Musa Alpaslan, Osman Parlak, Ali̇ Uçurum

Turkish Journal of Earth Sciences

Major, trace element and K-Ar age determinations are reported for a suite from the Yamadağı volcanics in the Eastern Anatolia. The exposed rocks mainly consist of medium-potassium calc-alkaline basaltic andesites, andesites and dacites. Petrographical data exhibit disequilibrium mineral textures, such as resorption of the ferromagnesian phases, clinopyroxene-mantled orthopyroxene, and sieve-textured plagioclases. The Yamadağı volcanics have a calk-alkaline character, and trace element characteristics exhibit that the volcanics resemble subduction zone volcanics and/or volcanics assimilated by continental crust. K/Ar age determinations show that the Yamadağı volcanics were formed during the 12 ± 0.5 - 15 ± 0.5 Ma time interval. Geochemical characteristics …

Arkosic Rocks From The San Andreas Fault Observatory At Depth (Safod) Borehole, Central California: Implications For The Structure And Tectonics Of The San Andreas Fault Zone, S. D. Springer, James P. Evans, J. I. Garver, D. Kirschner, Susanne U. Janecke

Geosciences Faculty Publications

The San Andreas Fault Observatory at Depth (SAFOD) drill hole encountered indurated, high-seismic-velocity arkosic sedimentary rocks west of the active trace of the San Andreas fault in central California. The arkosic rocks are juxtaposed against granitic rocks of the Salinian block to the southwest and against fine-grained Great Valley Group and Jurassic Franciscan rocks to the northeast. We identify three distinct lithologic units using cuttings, core petrography, electrical resistivity image logs, zircon fission-track analyses, and borehole-based geophysical logs. The upper arkose occurs from 1920 to 2530 m measured depth (mmd) in the borehole and is composed of five structural blocks …

Temporal And Geochemical Insights Related To Volcanic And Plutonic Activity Within Big Bend National Park, Texas, Daniel Paul Miggins

Open Access Theses & Dissertations

Big Bend National Park located in the southeastern part of the Trans-Pecos Magmatic Province in west Texas contains a diverse suite of volcanic and intrusive rocks. Ongoing geologic mapping, geochronology, and geochemical studies have focused on the timing and geological relationships associated with these volcanic and intrusive rocks. Igneous activity within Big Bend National Park occurred from 46.5 to 22.0 Ma. Precise 40Ar/39Ar and U-Pb zircon geochronology has resolved the timing of this activity into five discrete episodes: 1) eruption and emplacement of both intrusive and volcanic mafic rocks at 46.5 Ma followed by ~42.0 Ma mafic volcanic pulse; 2) …

Investigating The Margins Of Pleistocene Lake Deposits With High-Resolution Seismic Reflection In Pilot Valley, Utah, John V. South

Theses and Dissertations

A vast area of the northeastern Great Basin of the western USA was inundated by a succession of Plio-Pleistocene lakes, including Lake Bonneville (28 ka to 12 ka). The Pilot Valley playa, located just east of the Utah-Nevada border near Wendover, Utah, within the eastern Basin and Range Province, represents an 8 to 16 km wide and ~50 km long remnant of these lakes. The playa corresponds to the upper surface of a closed basin that is delimited by two mountain ranges, which are mantled by recent alluvial fans over which the playa sediments have prograded. In order to investigate …

In Memoriam

Studia UBB Geologia

No abstract provided.

Gsi: Geo Scene Investigation! On-Site Programming (Grade 7), Discover Mojave: Forever Earth

Curriculum materials (FE)

GSI: Geo Scene Investigation! introduces students to the differences between observations and interpretations and to some of the fundamental principles of geology. Students identify specific geologic processes and landforms in the landscape surrounding them at Lake Mead National Recreation Area (NRA) by solving mysteries with a set of geology-related clues.

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 …

Gsi: Geo Scene Investigation! On-Site Programming, Support Materials (Grade 7), Discover Mojave: Forever Earth

Curriculum materials (FE)

What happened geologically to produce the landscape we see today? What was the stage like that ultimately produced the Colorado River? What are the processes that are still at work today?

To begin exploring and discovering the answers to these questions, we can look at what’s happened in the past and also examine the clues that are evident on today’s landscape. Lake Mead’s geologic past can be organized like acts in a play. These geologic “acts” represent the area’s significant geologic events. The acts are not equal in terms of time (millions of years), nor is all geologic time accounted …

Finding Concealed Active Faults: Extending The Southern Whidbey Island Fault Across The Puget Lowland, Washington, Brian L. Sherrod, Richard J. Blakely, Craig S. Weaver, Harvey M. Kelsey, Elizabeth Barnett, Lee Liberty, Karen L. Meagher, Kristin Pape

CGISS Publications and Presentations

The southern Whidbey Island fault zone (SWIF), as previously mapped using borehole data, potential field anomalies, and marine seismic reflection surveys, consists of three subparallel, northwest trending strands extending ~100 km from near Vancouver Island to the northern Puget Lowland. East of Puget Sound, the SWIF makes landfall between the cities of Seattle and Everett but is concealed beneath a thick mantle of young glacial deposits and vegetation. A ~20-km-wide, northwest trending swath of subparallel, low-amplitude aeromagnetic anomalies crosses this region of the Puget Lowland and is on strike with the SWIF. The most prominent aeromagnetic anomaly, the Cottage Lake …

Geology Of The Southern Reveille Range, Nye County, Nevada, Matthew Alan Mckelvey

UNLV Theses, Dissertations, Professional Papers, and Capstones

The Reveille Range in central Nevada provides a unique window into the mid-Miocene geology and volcanology of the central Great Basin during the "ignimbrite flare up." Although faulted along its margins, the interior of the range is relatively undeformed thus preserving volcanic centers. The Reveille Range contains three mid-Miocene caldera complexes. Previous studies have identified the Goblin Knobs caldera (25.6 Ma) in the central Reveille Range and the caldera of northern Reveille Range (25.3 Ma) to the north. These calderas are completely filled with intracaldera tuffs. This study has identified a younger third caldera located in the southern part of …

Provenance Analysis Of The Cretaceous Pythian Cave Conglomerate, Northern California, Gregory Alan Augsburger

Earth and Environmental Geosciences Student Honors Theses

Reconstructions of the Mesozoic paleogeography of the North American Cordillera depend on data that can link displaced terranes to each other and/or to the North American craton. The Pythian Cave Conglomerate (PCC) sits unconformably on the eastern terranes of the Klamath Mountains south of Yreka, California and has the potential to yield valuable information about the tectonic history of the region. The PCC is approximately 60 m thick, with the lower 40 m dominated by cobble conglomerate with thin sandstone lenses, and the upper 20 m containing thicker and more laterally continuous interbedded sandstone layers. Originally interpreted as Tertiary conglomerate …

An Ordovician Global Reference Section Recently Selected In Oklahoma, Daniel Goldman, Stephen A. Leslie, Stig M. Bergström, Jaak Nõlvak, Seth A. Young, Stanley C. Finney

Department of Earth, Environment and Sustainability Faculty Publications

Ordovician fossil faunas are characterized by a marked biogeographic differentiation that results in a minimal similarity between most North American faunas and those of major Ordovician areas elsewhere in the world. This provincial distribution of most fossils has led to establishment of different schemes of fossil-based regional stages in, for instance, North America, Baltoscandia, China, and the British Isles.

Because these chrono-stratigraphic units have been largely based on shelly fossils with distributions restricted to a particular region, it has been impossible in most cases to establish a precise international correlation of these regional stages. Furthermore, some general terms, such as …

Backstripping The Chesapeake Bay Impact Structure: Differentiating Regional Tectonics From Impact Effects, Travis Gary Hayden

Masters Theses

The Chesapeake Bay impact structure is a ca. 35.4 Ma old crater located on the coastal plain of Virginia along the eastern seaboard of North America. The impact generated a crater between 85 and 90 km in diameter, and over 2000 meters deep. Deposition returned to normal shortly after impact, resulting in a unique record of both the impact related and subsequent passive margin sedimentation. We use backstripping to show that the impact strongly affected sedimentation for 7 m.y. through a combination of impact derived crustal scale tectonics, dominated by the introduction and subsequent removal of a negative thermal anomaly, …

Pamphlet To Accompany Geologic Map Gmc-34: Geologic Map Of The O’Neill 1º X 2º Quadrangle, Nebraska, With Configuration Maps Of Surfaces Of Formations, Robert F. Diffendal Jr., Michael R. Voorhies, E. Jane Voorhies, H. E. Lagarry, C. L. Timperley, M. E. Perkins

Robert F. Diffendal, Jr., Publications

This map is necessarily generalized. It is based primarily on data from 7.5’ surficial geologic quadrangle maps of the map area prepared by the authors principally from 1991 to 2000, from Voorhies (unpublished data, 1974), as well as data from test-hole drilling done across the quadrangle by the Conservation and Survey Division, University of Nebraska, and its cooperators over many years since the 1930s. For more detailed information, consult the geologic data files of the Conservation and Survey Division, School of Natural Resources, University of Nebraska-Lincoln. The quadrangle is mostly covered by vegetation and Holocene sediments. Limited good exposures of …

Geological Mapping Of Orhon, Tariat, And Egiin Dawaa, Central Mongolia, Through The Interpretation Of Remote Sensing Data, Tara Alexandra Stolz

Browse all Theses and Dissertations

Multi-spectral satellite data from the Advanced Spaceborn Thermal Emission and Reflection Radiometer (ASTER) and Landsat Thematic Mapper (TM) were used to make interpretations regarding the surface lithology and structure of the Tariat, Egiin Dawaa, and Orhon regions in Central Mongolia. These areas experienced widespread Cenozoic volcanism. This study mapped the locations and extents of the volcanic flows, located cinder cones and faults evident in the areas, and identified a possible exposure of the Mongolian granitic batholith in the Orhon area. ER Mapper, a geospatial imaging software, was used to generate and run algorithms. Image transforms and supervised classifications were used …

In Memoriam Jean Philippe Marcoux, A.M. Celal Şengör

Turkish Journal of Earth Sciences

No abstract provided.

Composition, Microstructures, And Petrophysics Of The Mozumi Fault, Japan: In Situ Analyses Of Fault Zone Properties And Structure In Sedimentary Rocks From Shallow Crustal Levels, Angela J. Isaacs, James P. Evans, Peter T. Kolesar, Tsuyoshi Nohara

Geosciences Faculty Publications

[1] We characterize the chemical, microstructural, and geophysical properties of fault-related rock samples from the 80–100 m wide Mozumi fault zone, north central Honshu, Japan. The fault is exposed in a research tunnel 300–400 m below the ground, and we combine geological data with borehole geophysical logs to determine the elastic and seismic properties of the fault zone. Detailed mapping within the tunnel reveals that the fault zone consists of two zones of breccia to foliated cataclasites 20 and 50 m thick. Two narrow (tens of centimeters wide) principal slip zones on which most of the slip occurred bound the …

Modern Strain Localization In The Central Walker Lane, Western United States: Implications For The Evolution Of Intraplate Deformation In Transtensional Settings, Benjamin E. Surpless

Earth and Environmental Geosciences Faculty Research

Approximately 25% of the differential motion between the Pacific and North American plates occurs in the Walker Lane, a zone of dextral motion within the western margin of the Basin and Range province. At the latitude of Lake Tahoe, the central Walker Lane has been considered a zone of transtension, with strain accommodated by dip-slip, strike-slip, and oblique-slip faults. Geologic data indicate that extension and strike-slip motion are partitioned across the central Walker Lane, with dip-slip motion resulting in E–W to ESE–WNW extension along the present-day western margin of the central Walker Lane since approximately 15 Ma, and dextral strike-slip …

Middle Crustal Ductile Deformation Patterns In Southern Tibet: Insights From Vorticity Studies In Mabja Dome, Jackie Langille

All Master's Theses

Mabja Dome, southern Tibet, exposes mid-crustal rocks proposed to have originated from a southward flowing mid-crustal channel. Kinematic, mean kinematic vorticity (Wm), and metamorphic petrography analyses on these mid-crustal rocks were performed to test this hypothesis. Kinematic indicators show a transition with structural depth from top-north and top-south shear to solely top-south shear. Along the northernmost transects, Wm in schists and orthogneisses range from 0.52–0.84 (63–36% pure shear). Wm for quartzites ranges from 0.9–0.99 (27–1% pure shear). Deformation temperatures increase from ~450 °C in the chloritoid-zone to ~700 °C in the sillimanite-zone and were recorded between ~35–16 Ma. These patterns …

Turbulent Lifestyle: Microbial Mats On Earth’S Sandy Beaches—Today And 3 Billion Years Ago, Nora Noffke

OES Faculty Publications

Archean Earth history is very difficult to reconstruct. Until recently, only bacterial cells preserved in chert, microborings, and stromatolites provided the few clues to ancient life. Now, siliciclastic “microbially induced sedimentary structures” (MISS) are adding to our knowledge of both past life and paleoenvironments. MISS rise from the interaction of photoautotrophic microbial mats with physical sediment dynamics in siliciclastic, shallow-marine settings. Archean MISS can be understood through observations of living microbial mats and modern biotic-physical sedimentary processes. Such geobiological studies are key to the interpretation of the early evolution of prokaryotes. For example, the 2.9 Ga Pongola Supergroup, South Africa, …

The Global Stratotype Section And Point (Gssp) For The Base Of The Katian Stage Of The Upper Ordovician Series At Black Knob Ridge, Southeastern Oklahoma, Usa, Daniel Goldman, Stephen A. Leslie, Jaak Nõlvak, Seth Young, Stig M. Bergström, Warren D. Huff

Department of Earth, Environment and Sustainability Faculty Publications

The International Subcomission on Ordovician Stratigraphy (ISOS) of the International Commission on Stratigraphy (ICS) recently defined the base of the global Upper Ordovician Series to be at the first appearance datum (FAD) of the graptolite species Nemagraptus gracilis in the Fågelsång GSSP in southern Sweden. This designation recognized the tremendous utility for global correlation of the first appearance of a cosmopolitan taxon that occurs within a consistent succession of other first appearance datums (e.g., Finney and Bergström, 1986; Bergström et al., 2000). Current efforts by the ISOS have focused on subdividing the Upper Ordovician into three stages and choosing appropriate …