Plankton Evolution Driven By Paleoceanographic Change: Prediscosphaera From The Mid-Cretaceous In The Western North Atlantic,
2012
University of Nebraska-Lincoln
Plankton Evolution Driven By Paleoceanographic Change: Prediscosphaera From The Mid-Cretaceous In The Western North Atlantic, Kristen L. Mitchell
Department of Earth and Atmospheric Sciences: Dissertations, Theses, and Student Research
Well-preserved nannofossil assemblages in late Albian and Cenomanian hemipelagic sections from Ocean Drilling Program (ODP) Leg 171B preserve a record of the early history and adaptive radiation of the calcareous nannofossil genus Prediscosphaera. There was a significant rise in the abundance of the genus (from an average of 2% in the early late Albian to about 6% in the latest Albian and Cenomanian. This rise, and other shorter term pulses of increased generic abundance, corresponds to black shale deposition episodes. Twelve distinct morphotypes that were derived from the long-ranging Prediscosphera columnata and Prediscosphaera spinosa, are recognized and differentiated …
Petrology Of Proterozoic To Tertiary Rocks In The Southern Burro Mountains, Nm: Insights Into Mazatzal To Basin And Range Magmatism And Tectonics,
2012
Stephen F Austin State University
Petrology Of Proterozoic To Tertiary Rocks In The Southern Burro Mountains, Nm: Insights Into Mazatzal To Basin And Range Magmatism And Tectonics, Theda Strickler
Undergraduate Research Conference
Analysis of thin sections from the Wind Mountain quadrangle, Burro Mountains, NM, near the Tyrone copper mine, reveals a complex geologic history. Rock samples collected in the study area were cut using a rock saw and thin sections were prepared and analyzed to determine mineral content and fabric patterns. The oldest rocks in the study area are strongly metamorphosed and locally mylonitized Proterozoic quartzofeldspathic gneisses and amphibolites of Mazatzal affinity. Mineralogical indications of shearing correlate with shear zones observed during field mapping in the area. Another set of samples are of younger Proterozoic granites and metagranites that intruded the country …
U/Pb Detrital Zircon Study Of The Upper Cretaceous To Miocene Strata Of Kodiak Island, Alaska,
2012
Department of Geological Sciences, University of Texas at El Paso
U/Pb Detrital Zircon Study Of The Upper Cretaceous To Miocene Strata Of Kodiak Island, Alaska, Sarah J. Olivas^, Cameron Davidson, John I. Garver, Diane I. Doser*, Hannah Hilbert-Wolf
COURI Symposium Abstracts, Spring 2012
No abstract provided.
Tidally Driven Coulomb Failure Along Europa's Agenor Linea,
2012
Department of Geological Sciences, University of Texas at El Paso
Tidally Driven Coulomb Failure Along Europa's Agenor Linea, Marissa Cameron^, Amanda Nahm, Robert Pappalardo, Bridget Smith-Konter*
COURI Symposium Abstracts, Spring 2012
No abstract provided.
Temporal And Spatial Analysis Of Monogenetic Volcanic Fields,
2012
University of South Florida
Temporal And Spatial Analysis Of Monogenetic Volcanic Fields, Koji Kiyosugi
USF Tampa Graduate Theses and Dissertations
Achieving an understanding of the nature of monogenetic volcanic fields depends on identification of the spatial and temporal patterns of volcanism in these fields, and their relationships to structures mapped in the shallow crust and inferred in the deep crust and mantle through interpretation of geochemical, radiometric and geophysical data.
We investigate the spatial and temporal distributions of volcanism in the Abu Monogenetic Volcano Group, Southwest Japan. E-W elongated volcano distribution, which is identified by a nonparametric kernel method, is found to be consistent with the spatial extent of P-wave velocity anomalies in the lower crust and upper mantle, supporting …
Geologic Mapping Of The South Tibetan Detachment System In Western Bhutan Using Aster Multispectral Data,
2012
Department of Geological Sciences, University of Texas at El Paso
Geologic Mapping Of The South Tibetan Detachment System In Western Bhutan Using Aster Multispectral Data, Adam H. Nazarian ^, Jose M. Hurtado Jr.*
COURI Symposium Abstracts, Spring 2012
Remotely sensed data is a powerful tool for studying geology in areas where traditional field geology proves costly or difficult. This study focuses on geologic mapping of the South Tibetan Detachment System (STDS) in the area where Bhutan, India, and China meet. Having improved geologic maps is important as background information for better understanding the evolution and structure of the regional geology. Advanced Spaceborne Thermal Emission and Reflectance Radiometer (ASTER) multispectral imagery was used to differentiate the low-grade metamorphosed Tethyan Sedimentary Sequence (TSS) of the hanging wall from the mid- to high-grade metamorphosed Greater Himalayan Sequence (GHS) of the footwall. …
Reservoir Potential Of Sands Formed In Glaciomarine Environments: An Analog Study Based On Cenozoic Examples From Mcmurdo Sound, Antarctica,
2012
University of Nebraska-Lincoln
Reservoir Potential Of Sands Formed In Glaciomarine Environments: An Analog Study Based On Cenozoic Examples From Mcmurdo Sound, Antarctica, Christopher R. Fielding, Brian A. Blackstone, Tracy D. Frank, Zi Gui
Department of Earth and Atmospheric Sciences: Faculty Publications
This paper provides documentation of unexpectedly high-reservoir-quality glaciomarine sands found in the Cenozoic succession beneath McMurdo Sound, Antarctica, as an analogue study for evaluations of hydrocarbon prospectivity in basins elsewhere. The Oligocene to Lower Miocene succession of the Victoria Land Basin, an extant portion of the West Antarctic Rift System, comprises diamictites, mudrocks, and sandstones with minor conglomerates. These lithologies are arranged in repetitive stacking patterns (cycles), interpreted to record repeated advance and retreat of glaciers into and out of the basin, with attendant eustatic and isostatic effects. Phases of ice retreat within the cycles comprise an array of mudrocks, …
Evaluating The Effects Of Lithofacies And Thin Shales On The Lateral Distribution Of Hydrothermal Dolomite Reservoirs In The Michigan Basin,
2012
Western Michigan University
Evaluating The Effects Of Lithofacies And Thin Shales On The Lateral Distribution Of Hydrothermal Dolomite Reservoirs In The Michigan Basin, Peter J. Feutz
Masters Theses
The southern Michigan Basin contains numerous hydrothermal dolomite hydrocarbon fields, including the giant Albion-Scipio Field. The fields typically encompass narrow zones of faulting and fracturing which have been altered from a tight host limestone into a more porous and permeable dolomite by upward-moving hydrothermal fluids. Alternating layers of dolomite that spread laterally away from the main vertical fault conduits imply that structure alone may not define the resulting reservoir architectures within the region. A detailed analysis of primary depositional facies and thin shale seams suggests that secondary stratigraphic controls play a significant role in the development of reservoir rock within …
Wilson Cycles, Tectonic Inheritance, And Rifting Of The North American Gulf Of Mexico Continental Margin,
2012
Central Washington University
Wilson Cycles, Tectonic Inheritance, And Rifting Of The North American Gulf Of Mexico Continental Margin, Audrey D. Huerta, Dennis L. Harry
Geological Sciences Faculty Scholarship
The tectonic evolution of the North American Gulf of Mexico continental margin is characterized by two Wilson cycles, i.e., repeated episodes of opening and closing of ocean basins along the same structural trend. This evolution includes (1) the Precambrian Grenville orogeny; (2) formation of a rift-transform margin during late Precambrian opening of the Iapetus Ocean; (3) the late Paleozoic Ouachita orogeny during assembly of Pangea; and (4) Mesozoic rifting during opening of the Gulf of Mexico. Unlike the Atlantic margins, where Wilson cycles were first recognized, breakup in the Gulf of Mexico did not initially focus within the orogen, but …
Spectral Analysis Of Ground Magnetic Data In Magadi Area, Southern Kenya Rift,
2012
Jomo-Kenyatta University of Agriculture, Science and Technology, Department of Physics
Spectral Analysis Of Ground Magnetic Data In Magadi Area, Southern Kenya Rift, Jg Githiri, Jp Patel, Jo Barongo, Pk Karanja
Tanzania Journal of Science
The area surrounding Lake Magadi in the southern Kenya rift is characterized by hot springs that issue from fractures distributed along the shores of the lake. Presence of earthquake swarms that cluster in northern margin of Lake Magadi strongly indicate magmatic activity in the area. This study was done as a follow-up to investigate depth to the heat source possibly causing high seismic activity and high heat flow in the area. A ground magnetic survey was conducted to investigate geothermal potential of the area and a magnetic anomaly contour map prepared. Spectral analysis involving determining power spectrum was applied to …
Mg-Rich Metabasalts From The Southern Musoma –Mara Greenstone Belt: Possible Evidence For Mantle Plume Activity In The Tanzania Craton?,
2012
University of Dar es Salaam, Geology Department, P. O. Box 35052, Dar es Salaam, Tanzania.
Mg-Rich Metabasalts From The Southern Musoma –Mara Greenstone Belt: Possible Evidence For Mantle Plume Activity In The Tanzania Craton?, S Manya
Tanzania Journal of Science
Mg-rich metabasalts from the Simba Sirori to Majimoto segment of the southern Musoma-Mara greenstone belt are the most magnesian lavas reported in the Archaean Tanzania Craton. The lavas yielded a Sm-Nd isochron age of 2768 ± 38 Ma (MSWD = 1.2) and corresponding !Nd(2.7 Ga) values in the range of + 0.66 to + 2.81. The lavas exhibit high MgO contents of up to 16 wt %, Cr (140 – 1590 ppm), Ni (80 – 510 ppm), values which are higher than those of primitive NMORB, but are comparable with those of Archaean komatiitic basalts and modern oceanic plateau basalts. …
Feeding Habitats Of The Gulf Sturgeon, Acipenser Oxyrinchus Desotoi, In The Suwannee And Yellow Rivers, Florida, As Identified By Multiple Stable Isotope Analyses,
2012
U.S. Geological Survey
Feeding Habitats Of The Gulf Sturgeon, Acipenser Oxyrinchus Desotoi, In The Suwannee And Yellow Rivers, Florida, As Identified By Multiple Stable Isotope Analyses, Kenneth J. Sulak, J. J. Berg, M. Randall
United States Geological Survey: Staff Publications
Stable 13C, 15N, and 34S isotopes were analyzed to define the feeding habitats of Acipenser oxyrinchus desotoi in the Suwannee and Yellow River populations. For the majority (93.9%) of Suwannee sub adults and adults, 13C and 34S signatures indicate use of nearshore marine waters as primary winter feeding habitat, probably due to the limiting size of the Suwannee Sound estuary. In the Yellow River population, 13C isotope signatures indicate that adults remain primarily within Pensacola Bay estuary to feed in winter, rather than immigrating to the open Gulf of Mexico. A minor Suwannee River subset (6% of …
Heterogeneous Detection Probabilities For Imperiled Missouri River Fishes: Implications For Large-River Monitoring Programs,
2012
Kansas Cooperative Fish and Wildlife Research Unit, Division of Biology, Kansas State University & Present address: U.S. Fish and Wildlife Service, Ashland Fish and Wildlife Conservation Office
Heterogeneous Detection Probabilities For Imperiled Missouri River Fishes: Implications For Large-River Monitoring Programs, Joshua T. Schloesser, Craig P. Paukert, Wyatt J. Doyle, Tracy D. Hill, Kirk D. Steffensen, Vince H. Travnichek
United States Geological Survey: Staff Publications
Occupancy modeling was used to determine (1) if detection probabilities (p) for 7 regionally imperiled Missouri River fishes (Scaphirhynchus albus, Scaphirhynchus platorynchus, Cycleptus elongatus, Sander canadensis, Macrhybopsis aestivalis, Macrhybopsis gelida, and Macrhybopsis meeki) differed among gear types (i.e. stationary gill nets, drifted trammel nets, and otter trawls), and (2) how detection probabilities were affected by habitat (i.e. pool, bar, and open water), longitudinal position (five 189 to 367 rkm long segments), sampling year (2003 to 2006), and season (July 1 to October 30 and October 31 to June 30). Adult, large-bodied fishes were …
Habitat And Prey Availability Attributes Associated With Juvenile And Early Adult Pallid Sturgeon Occurrence In The Missouri River, Usa,
2012
US Geological Survey, South Dakota Cooperative Fish and Wildlife Research Unit, Department of Wildlife and Fisheries Sciences & Present address: Minnesota Pollution Control Agency,
Habitat And Prey Availability Attributes Associated With Juvenile And Early Adult Pallid Sturgeon Occurrence In The Missouri River, Usa, Bryan D. Spindler, Steven R. Chipps, Robert A. Klumb, Brian D. S. Graeb, Michael C. Wimberly
United States Geological Survey: Staff Publications
The pallid sturgeon Scaphirhynchus albus is a federally endangered species native to the Missouri and lower Mississippi Rivers, USA. As part of recovery efforts, over 360 000 pallid sturgeon have been stocked into the Missouri River since 1994, and a standardized, long-term monitoring program was initiated in 2003. Understanding the distribution and habitat requirements of juvenile and early adult pallid sturgeon (fork length <720 mm, age <10 yr) is an important goal of the monitoring and recovery programs. In this study, we collected information on habitat characteristics and prey availability from the upper Missouri River along the Nebraska-South Dakota border and compared these attributes between capture (present) and non-capture (absent) locations (N = 59). To evaluate the relative influence of habitat and prey availability on pallid sturgeon occurrence, we examined several candidate models using an informationtheoretic approach. A prey availability model had the most support and included site-specific information on Diptera and Ephemeroptera abundance. A habitat-based model showed that juveniles and early adults were found in relatively deeper water and avoided areas where bottom velocities were greater than 1.2 m s−1. Although not as well supported as the prey-effects model (evidence ratio = 6.4), habitat features also provided a plausible model for predicting occurrence. The models developed here could be used to evaluate pallid sturgeon habitat potential in the Missouri River basin and help guide future monitoring and conservation management of this endangered species.
Projecting Changes In Extreme Precipitation In The Midwestern United States Using North American Regional Climate Change Assessment Program (Narccap) Regional Climate Models,
2012
University of Dayton
Projecting Changes In Extreme Precipitation In The Midwestern United States Using North American Regional Climate Change Assessment Program (Narccap) Regional Climate Models, Shuang-Ye Wu
Department of Earth, Environment and Sustainability Faculty Publications
Based on the physics of global circulation, many expect an enhanced greenhouse effect to lead to a more active hydrological cycle with more precipitation on average (Hennessy et al. 1997). This expected increase has been found in observations (Zhang et al. 2007) and has also been suggested by climate models, although these models are not consistent with respect to the spatial and temporal variability about this change. An increase in mean precipitation depth, assuming no change in the shape of the frequency distribution, would imply an increased frequency of heavy-precipitation events. However, some studies (Hennessy et al. 1997, Allen and …
Mafic Alkaline Magmatism In The East Tintic Mountains, West-Central Utah: Implications For A Late Oligocene Transition From Subduction To Extension,
2012
Brigham Young University - Provo
Mafic Alkaline Magmatism In The East Tintic Mountains, West-Central Utah: Implications For A Late Oligocene Transition From Subduction To Extension, Tara Laine Allen
Theses and Dissertations
Voluminous Eocene to Oligocene intermediate to silicic volcanic rocks related to subduction erupted throughout the Great Basin and were supplanted by bimodal eruptions of basalt and rhyolite related to extension in the Miocene. Locally, in the northern East Tintic Mountains of central Utah, this important transition is marked by a distinctive package of mafic alkaline magmas that reveal important details about the nature of this fundamental change. A late Oligocene anorthoclase-bearing shoshonite lava in the Boulter Peak quadrangle contains megacrysts of anorthoclase, with phenocrysts of olivine, clinopyroxene, magnesiohastingsite, magnetite, and apatite. The anorthoclase grains occur as glomerocrysts with irregular, resorbed …
Geodetic Constraints On San Francisco Bay Area Fault Slip Rates And Potential Seismogenic Asperities On The Partially Creeping Hayward Fault,
2012
Harvard University
Geodetic Constraints On San Francisco Bay Area Fault Slip Rates And Potential Seismogenic Asperities On The Partially Creeping Hayward Fault, Eileen L. Evans, John P. Loveless, Brendan J. Meade
Geosciences: Faculty Publications
The Hayward fault in the San Francisco Bay Area (SFBA) is sometimes considered unusual among continental faults for exhibiting significant aseismic creep during the interseismic phase of the seismic cycle while also generating sufficient elastic strain to produce major earthquakes. Imaging the spatial variation in interseismic fault creep on the Hayward fault is complicated because of the interseismic strain accumulation associated with nearby faults in the SFBA, where the relative motion between the Pacific plate and the Sierra block is partitioned across closely spaced subparallel faults. To estimate spatially variable creep on the Hayward fault, we interpret geodetic observations with …
Response Of A Carbonate Platform To The Cenomanian-Turonian Drowning And Oae 2: A Case Study From The Adriatic Platform (Dalmatia, Croatia),
2012
Croatian Geological Survey
Response Of A Carbonate Platform To The Cenomanian-Turonian Drowning And Oae 2: A Case Study From The Adriatic Platform (Dalmatia, Croatia), Tvrtko Korbar, B. Glumac, Blanka Cvetko Tesovic, Sarah B. Cadieux
Geosciences: Faculty Publications
Global perturbations during the Cenomanian–Turonian boundary (CTB) interval and the Oceanic Anoxic Event 2 (OAE 2) represent one of the most extensively studied past environmental changes. To explore the response of various carbonate-platform depositional systems to such major environmental perturbations, strata of the intra-Tethyan Adriatic carbonate platform (sensu stricto) from the island of Bracˇ (Adriatic Sea, Croatia) provide excellent exposures and a previously well-established Upper Cretaceous lithostratigraphic framework. Within this context, this study integrated lithostratigraphy, biostratigraphy, and chemostratigraphy to describe a drowned-platform succession underlain and overlain by peritidal carbonates. Carbon-isotope stratigraphy of this succession revealed a shift towards positive d13C …
Real-Time Change And Damage Detection Of Landslides And Other Earth Movements Threatening Public Infrastructure,
2012
Oregon State University
Real-Time Change And Damage Detection Of Landslides And Other Earth Movements Threatening Public Infrastructure, Michael J. Olsen, Shawn Butcher, Evon P. Silvia
TREC Final Reports
Geologic hazards such as coastal erosion, landslides, seismic loading, etc. constantly threaten public highway construction and maintenance. Repeat surveys using terrestrial laser scanning (TLS, ground-based LiDAR) enable rapid 3D data acquisition to map, see, analyze, and understand the processes generating such problems. Previously, change detection and analysis between scan surveys was conducted during post-processing upon return to the office, instead of while collecting data in the field. Change detection in the field improves the effectiveness and efficiency of the field investigation. We have developed a new algorithm that quickly geo-references scans upon field acquisition and simultaneously performs change detection by …
Particle Transport Over Rough Hillslope Surfaces By Dry Ravel: Experiments And Simulations With Implications For Nonlocal Sediment Flux,
2012
San Jose State University
Particle Transport Over Rough Hillslope Surfaces By Dry Ravel: Experiments And Simulations With Implications For Nonlocal Sediment Flux, Emmanuel Gabet, Morgan Mendoza
Faculty Publications
Past studies of hillslope evolution have typically assumed that soil creep processes are governed by a linear relationship between local hillslope angle and transport distance. The assumption of “linear diffusion” has fallen out of favor because, when coupled with an expression of mass continuity, it yields unrealistic hillslope profiles. As a consequence, a better understanding of the mechanics of sediment transport is needed. Here we report results from a series of flume experiments performed to investigate sediment transport by dry ravel, a common soil creep process in arid and semiarid environments. We find that, at gentle slopes, transport distances follow …
