Geology Commons^™

Provenance Of A Garnet-Rich Beach Placer Deposit, Montauk Point, Long Island, Ny, Nazrul I. Khandaker, Stanley Schleifer, Zarine Ali, Olalekan Jemilugba

Publications and Research

Garnet and magnetite rich sand, also enriched in monazite and zircon, has been observed and sampled near Montauk Point, Long Island. The sediment is derived from the glacial till and stratified drift of the Ronkonkoma Moraine by mechanical weathering and erosion due to wave action at Montauk Point, the headland on the eastern tip of Long Island. Sand sized sediment is moved westward along the southern shore of Long Island by longshore transport. The garnet and magnetite components of this sediment are significantly denser than the quartzo-feldspathic components. This allows for hydraulic segregation of these components, by wave action, …

Halogen Emissions From A Small Volcanic Eruption: Modeling The Peak Concentrations, Dispersion, And Volcanically Induced Ozone Loss In The Stratosphere, G. A. Millard, T. A. Mather, D. M. Pyle, William I. Rose, B. Thornton

Department of Geological and Mining Engineering and Sciences Publications

Aircraft measurements in the Hekla, Iceland volcanic plume in February 2000 revealed large quantities of hydrogen halides within the stratosphere correlated to volcanic SO2. Investigation of the longer-term stratospheric impact of these emissions, using the 3D chemical transport model, SLIMCAT suggests that volcanic enhancements of H2O and HNO3 increased HNO3·3H2O particle availability within the plume. These particles activated volcanic HCl and HBr, enhancing model plume concentrations of ClOx (20 ppb) and BrOx (50 ppt). Model O3 concentrations decreased to near-zero in places, and plume average O3 remained 30% lower after two weeks. Reductions in the model O3column reduced UV shielding …

Geogram 2006, David J. Keeling Editor, Wku Department Of Geography And Geology

Earth, Environmental, and Atmospheric Sciences Publications

No abstract provided.

The Jabal Qarah Caves Of The Hofuf Area, Northeastern Saudi Arabia: A Geological Investigation, Nazrul I. Khandaker, Mahbub Hussain, Fadhel Al-Khalifah

Publications and Research

The Jabal Al Qarah Caves, located approximately 13 km east of Al Hofuf, Eastern Province of Saudi Arabia, are an intricate cave system developed in the calcareous sandstone, marl and clay of the Upper Miocene to Lower Pliocene Hofuf Formation. Physiographically, the hill of Jabal Al Qarah is an outlier mesa that is located at the eastern edge of the Shedgum Plateau, the southern extension of the As Summan Plateau, and the larger Syrian Plateau to the north. Based on cave morphology and interpreted evolutionary histoty, the Jabal Al Qarah caves appear to be significantly different from other limestone caves …

Precarious Rock Methodology For Seismic Hazard: Physical Testing, Numerical Modeling, And Coherence Studies, Rasool Anooshehpoor, James N. Brune, Amy J. Smiecinski, Raymond E. Keeler

Publications (YM)

The precarious rock methodology used for seismic hazard assessment includes location, age dating, field measurements of the quasi-static toppling acceleration of balanced rocks, and study of their dynamic response to realistic strong motion seismograms using numerical modeling. The work scope is contained in the task description issued by the DOE to the Seismology Laboratory of the University of Nevada, Reno and is itemized in section 2.3 below. In addition, measurement of the coherence of seismic energy at high frequencies, critical to the understanding of the variability of high frequency ground motions at the repository level, will be estimated based on …

Detection Of A Landslide Glide Plane Using Seismic Reflection Methods: Investigation At Little Valley Landslide In Draper, Utah, Brady E. Tingey

Theses and Dissertations

An integration of geological and geophysical techniques has been used to characterize the internal structure of the Little Valley Landslide in Draper, Utah, USA. The Little Valley Landslide is a pre-historic landslide as old as 13ka B.P. It is found to consist of chaotic and disturbed weathered volcanic units derived from Tertiary age volcanics that comprise a great portion of the Wasatch Range. Geotechnical investigations that were integrated with the geophysical results included excavation of trenches and drilling of boreholes. Geophysical methods, in particular high-resolution seismic data, were used to provide a framework for interpreting the geotechnical observations. High-resolution seismic …

Microbial Growth And Biofilm Formation In Geologic Media Is Detected With Complex Conductivity Measurements, Caroline A. Davis, Estella A. Atekwana, Eliot A. Atekwana, Lee D. Slater, Silvia Rossbach, Melanie R. Mormile

Geosciences and Geological and Petroleum Engineering Faculty Research & Creative Works

Complex conductivity measurements (0.1-1000 Hz) were obtained from biostimulated sand-packed columns to investigate the effect of microbial growth and biofilm formation on the electrical properties of porous media. Microbial growth was verified by direct microbial counts, pH measurements, and environmental scanning electron microscope imaging. Peaks in imaginary (interfacial) conductivity in the biostimulated columns were coincident with peaks in the microbial cell concentrations extracted from sands. However, the real conductivity component showed no discernible relationship to microbial cell concentration. We suggest that the observed dynamic changes in the imaginary conductivity (σ″) arise from the growth and attachment of microbial cells and …

Mapped Overland Distance Of Paleotsunami High-Velocity Inundation N Back-Barrier Wetlands Of The Central Cascadia Margin, U.S.A, Robert B. Schlichting, Curt D. Peterson

Geology Faculty Publications and Presentations

Investigations of back-barrier, open-coastal plain settings have been used to establish minimum inundation distances of prehistoric tsunamis produced by great subduction zone earthquakes in the central Cascadia margin. Distinctive sand sheets were characterized at four localities within the central Cascadia margin, a shoreline distance of about 250 km. The sand sheets vary in thickness from 0.2 to 25 cm. They thin in the landward direction and consist of well-sorted beach sand that fines upsection. Many of the sand sheets include capping layers of organic-rich detritus, as well as assimilated mud rip-up clasts and soil litter. Marine diatoms and bromine (i.e., …

Deep-Water Antipatharians: Proxies Of Environmental Change, B. Williams, M.J. Risk, S.W. Ross, K.J. Sulak

United States Geological Survey: Staff Publications

Deep-water (307–697 m) antipatharian (black coral) specimens were collected from the southeastern continental slope of the United States and the north-central Gulf of Mexico. The sclerochronology of the specimens indicates that skeletal growth takes place by formation of concentric coeval layers. We used 210Pb to estimate radial growth rate of two specimens, and to establish that they were several centuries old. Bands were delaminated in KOH and analyzed for carbon and nitrogen stable isotopes. Carbon values ranged from _16.4‰ to _15.7‰; the oldest specimen displayed the largest range in values. Nitrogen values ranged from 7.7‰ to 8.6‰. …

Sinkhole Structure Imaging In Covered Karst Terrain, Sarah E. Kruse, M. Grasmueck, Matthew Weiss, D. Viggiano

Geology Faculty Publications

Ground penetrating radar (GPR) and resistivity techniques have been widely used to map the locations of sinkholes in covered karst terrain. To determine whether a sinkhole is a likely preferential conduit for groundwater flow, however, requires higher-resolution imaging than that used in conventional sinkhole mapping surveys. Field observations combined with simulated surveys for a 15-m diameter 3-m deep sinkhole in west-central Florida are used to assess the resolution of GPR and resistivity surveys targeting the semiconfining unit that floors the sinkhole depression. 2D resistivity surveys clearly show the central depression as well as resistivity contrasts between the cover sediments within …

Maximum A Posteriori Resampling Of Noisy, Spatially Correlated Data, John A. Goff, Chris Jenkins, Brian R. Calder

Center for Coastal and Ocean Mapping

In any geologic application, noisy data are sources of consternation for researchers, inhibiting interpretability and marring images with unsightly and unrealistic artifacts. Filtering is the typical solution to dealing with noisy data. However, filtering commonly suffers from ad hoc (i.e., uncalibrated, ungoverned) application. We present here an alternative to filtering: a newly developed method for correcting noise in data by finding the “best” value given available information. The motivating rationale is that data points that are close to each other in space cannot differ by “too much,” where “too much” is governed by the field covariance. Data with large uncertainties …

Hydrochemistry In An Alpine Karst System, Sequoia And Kings Canyon National Parks, California, Joel Despain

Masters Theses & Specialist Projects

This study uses high-resolution, long-term conductivity, temperature, discharge, pH, and laboratory data from 2001 through 2003 from an alpine karst spring located at 2,500 m amsl in Sequoia National Park, California to reveal detailed chemical parameters of this karst system. The data show a system with a pronounced spring run-off, extended periods of base flow quiescence, storm responses tied to precipitation as rain or as snowfall, and clear diurnal and seasonal patterns of discharge. pH and spC values show an inverse relationship to discharge and temperature, which are generally in phase. Total inorganic carbon (TIC) and the fraction of mineral-derived …

Strategies For Reducing Mosquito-Borne Disease Vulnerability In Equine Populations: A Kentucky Case Study, Sara Dalton

Masters Theses & Specialist Projects

This research examined equine management practices that limit or contribute to the spread of West Nile virus and other mosquito-bome disease. I hypothesize that there is a relationship between equine management practices and outbreaks of mosquito-borne disease in horse populations. Improved and appropriate mosquito habitat management may limit the risk of mosquito-borne disease in humans and horses by helping to lower the mosquito populations. The study goals were to recognize equine management practices and mosquito prevention practices that foster outbreaks of mosquito-borne disease. This study used a questionnaire for county level analysis of equine management practices and the relationship to …

Seaside, Oregon, Tsunami Pilot Study : Modernization Of Fema Flood Hazard Maps, Frank I. González, Eric L. Geist, Costas Synolakis, Diego Rodriguez Arcas, Douglas Bellomo, David Carlton, Thomas Horning, Bruce Jaffe, Jeff Johnson, Utku Kânoğlu, Harold O. Mofjeld, Jean Newman, Thomas Parsons, Robert Peters, Curt D. Peterson, George Priest, Vasily V. Titov, Angie J. Venturato, Joseph Weber, Florence L. Wong, Ahmet Yalçıner

Geology Faculty Publications and Presentations

FEMA Flood Insurance Rate Map (FIRM) guidelines do not currently exist for conducting and incorporating tsunami hazard assessments that reflect the substantial advances in tsunami research achieved in the last two decades; this conclusion is the result of two FEMA-sponsored workshops and the associated Tsunami Focused Study (Chowdhury et al., 2005). Therefore, as part of FEMA's Map Modernization Program, a Tsunami Pilot Study was carried out in the Seaside/Gearhart, Oregon, area to develop an improved Probabilistic Tsunami Hazard Assessment (PTHA) methodology and to provide recommendations for improved tsunami hazard assessment guidelines. The Seaside area was chosen because it is typical …

Evidence Of An Active Enso And Pdq During The Mid-Holocene From A Costa Rican Speleothem, April D. Azouz

UNLV Theses, Dissertations, Professional Papers, and Capstones

Although the El Nino/Southern Oscillation (ENSO) is the most important source of inter-annual climate variability in the tropics, its Holocene history is poorly understood, particularly in Central America. A high resolution (-3.8 years/sample) paleoclimate record of Central American rainfall variability has been reconstructed from a U /Th-dated stalagmite (7890 to 6490 yrs B.P.) from Costa Rica to constrain the onset and variability of ENSO throughout the Holocene, and to determine its role in generating regional climate anomalies. I suggest drier conditions, forced by El Nino, are represented by higher 5180 values, and are correlative with higher 513C values, indicating that …

Stable Isotope Compositions Of Organic Carbon And Contents Of Organic Carbon And Nitrogen Of Lacustrine Sediments From Sub-Arid Northern Tanzania, Ann Muzuka

Tanzania Journal of Science

The stable isotope compositions of organic carbon (OC), and contents of OC and nitrogen for four sediment cores recovered from lakes Makat (located in the Ngorongoro Crater), Ndutu and Masek (located in the Serengeti Plains) are used to document sources of organic matter (OM) and climatic changes in sub-arid northern Tanzania during the late Pleistocene-Holocene period. Accelerate mass spectrometer (AMS) 14C ages on total OM for sediments collected from the Ngorongoro Crater Lake indicate that the sedimentation rate is approximately 17 cm/ka. The δC values from the 20 cm long core (short core) show a downcore increase, whereas that of …

Sediment Characteristics And Hydrodynamic Setting Of Reef Platform Sediments Of Kunduchi, North Of Dar Es Salaam Harbour, Y. W. Shaghude, N. Nyandwi, A. N. N. Muzuka, A. M. A. M. Dubi, O. U. Mwaipopo

Tanzania Journal of Science

Sediment grain size distribution, carbonate content and current velocities for the Kunduchi area are used to determine its hydrodynamic setting and sediment characteristics. The sediment mean grain size generally decreases northward. The sediments consist of medium to coarse sand south of the Tegeta River and fine sand further north. The sediment sorting values, which lack a north-south trend, vary from moderately well sorted to poorly sorted. The skewness of the sediment vary from near-symmetrical to very negatively skewed while the peakedness (kurtosis) varies from platykurtic to leptokurtic. The carbonate content increases with distance offshore, whereas the siliciclastic component decreases with …

The Provenance Of Eocene Tuff Beds In The Fossil Butte Member Of The Green River Formation Of Wyoming: Relation To The Absaroka And Challis Volcanic Fields, Matthew R. Chandler

Theses and Dissertations

The Green River Formation was deposited between 53.5 and 48.5 Ma. The Angelo, Fossil Butte, and Lower members of the Green River Formation at Fossil Basin, preserve ash fall tuffs deposited in ancient Fossil Lake. 40Ar/39Ar dating of sanidine yielded eruptive ages of 51.29 ± 1.29 Ma and 52.20 ± 3.08 Ma for two of the tuff beds within Fossil Basin. Immobile element and mineral compositions of Fossil Basin tuffs indicate that most tuffs erupted from a subduction zone originally as rhyolites and dacites. X-ray diffraction analyses reveal that the tuffs' glassy matrices have been altered to illite, calcite, clinoptilolite, …

Geophysical Investigations And Groundwater Modeling Of The Hydrologic Conditions At Masaya Caldera, Nicaragua, Richard Eric Macneil

USF Tampa Graduate Theses and Dissertations

Masaya volcano, Nicaragua, has been the site of tremendous Plinian basaltic eruptions. Two eruptions ~6,500 and 2,250 BP formed the 6 kilometer (km) x 11 km, northwest trending Masaya caldera. The present day active Santiago Crater within the caldera is the site of persistent volcano degassing and occasional phreatic explosions. While the mechanism responsible for these phreatic explosions is unclear, one possible explanation is the interaction of groundwater with the shallow magma chamber beneath Masaya. This interaction with meteoric water is supported by the substantial steam discharge from the vent, which is significantly larger than other similar volcanoes in the …

Anguilliform Larvae Collected Off North Carolina, Steve W. Ross, Tara L. Casazza, Andrea M. Quattrini, Kenneth J. Sulak

United States Geological Survey: Staff Publications

The distinctive larval stage of eels (leptocephalus) facilitates dispersal through prolonged life in the open ocean. Leptocephali are abundant and diverse off North Carolina, yet data on distributions and biology are lacking. The water column (from surface to 1,293 m) was sampled in or near the Gulf Stream off Cape Hatteras, Cape Lookout, and Cape Fear, North Carolina during summer through fall of 1999–2005, and leptocephali were collected by neuston net, plankton net, Tucker trawl, and dip net. Additional samples were collected nearly monthly from a transect across southern Onslow Bay, North Carolina (from surface to 91 m) from April …

A Stratigraphic And Geochronologic Analysis Of The Morrison Formation/Cedar Mountain Formation Boundary, Utah, Brent W. Greenhalgh

Theses and Dissertations

The Lower Cretaceous Cedar Mountain Formation preserves several vertebrate faunas and has the potential of providing critical timing information pertaining to Early Cretaceous dinosaurs and the Sierran magmatic arc. Historically, the Morrison/Cedar Mountain contact and the duration of the unconformity between them have been difficult or impossible to determine because 1) the formations were deposited in similar environments, 2) the basal Cedar Mountain Formation is composed of reworked Morrison Formation, and 3) there are no radiometric ages for the lower Cedar Mountain Formation. A stratigraphic study through central Utah reveals a diagnostic suite of pedogenic and sedimentologic characters across the …

Characterization Of Fracture Systems In Sublette County, Wyoming Using P-Wave And C-Wave 3d Seismic, Keith R. Johnson

Masters Theses

Birefringence of seismic shear waves has proven to be a useful tool for identifying fracture intensity and orientation in the subsurface. Naturally occurring fractures have been shown to contribute to the deliverability of natural gas production in some reservoir formations in Rocky Mountain sedimentary basins. A multicomponent 3D 3C seismic survey acquired on the southeastern end of Pinedale Anticline in Sublette County, Wyoming was mapped to characterize fault systems within the sedimentary section. The tectonic and depositional history in the study area was determined by literature search and by one-dimensional backstripping. Compressional and wrench fault systems were observed and mapped. …

Sedimentology And Stratigraphy Of The Pennsylvanian Saginaw Aquifer, Central Lower Michigan, U.S.A., Niah B. H. Venable

Masters Theses

The Saginaw Aquifer is an important bedrock aquifer serving the needs of over 400,000 people in the Tri-County area of the Central Lower Peninsula of Michigan. The aquifer is comprised of the Pennsylvanian Grand River and Saginaw Formations. This study focuses on expanding existing knowledge of the general sedimentologic and stratigraphic characteristics of these units using conventional geological methods including core analysis, local log to core correlation, local and regional log to log correlation, and biostratigraphy. Analysis of new core from the study area examines facies and depositional environments given cursory coverage in outcrop studies by past researchers.

Incised valley …

Field Studies Of Hydrophobic Filter Pack Performance In Free Product Monitoring And Recovery, Nathan J. Brandner

Masters Theses

Multiple field experiments were conducted to determine the performance of hydrophobic filter packs, compared to the hydrophilic industry standard filter pack in free product hydrocarbon recovery. Laboratory and field studies have been previously performed in support of enhancing free product hydrocarbon recovery with the use of hydrophobic filter pack designs. This study was an attempt to test the efficacy of using hydrophobic filter pack materials to enhance free product recovery.

Six recovery wells were installed at three field sites, each site utilizing a pair of recovery wells, one hydrophobic and one hydrophilic, to compare their performances. Fine-grained hydrophobic filter pack …

Geologic Map And Structural Analysis Of The Twin Rocks 7.5 Minute Quadrangle, Wayne County, Utah, Samuel C. Sorber

Theses and Dissertations

A new geologic map of the Twin Rocks 7.5 minute quadrangle primarily located within Capitol Reef National Park, south-central Utah, provides stratigraphic and structural detail not previously available. This map has also been instrumental in understanding the evolution and development of fluvial terraces associated with Sulfur Creek and the structural geology of the backlimb of the Miners Mountain uplift. Nine bedrock stratigraphic formations and eight types of Quaternary deposits were mapped throughout the quadrangle. Bedrock stratigraphy ranges in age from Permian to Jurassic. New details absent on previous geologic maps include members of the Chinle and Moenkopi Formations and the …

Dendrochronological Analysis Of Smithville Community Historical Society Cabin And House, Smithville, Ohio

Historic Structures

Dating historical structures in Wayne County, Ohio using dendrochronology. The Historical Structures collection consists of reports that are the result of dendochronological analysis of timbers from structures in Pennsylvania and Ohio. Contributors: Lehmann, Sophie; Wiles, Greg

Kinematics Of Orocline Tightening In The Core Of An Arc: Paleomagnetic Analysis Of The Ponga Unit, Cantabrian Arc, Northern Spain, Arlo Brandon Weil

Geology Faculty Research and Scholarship

Paleomagnetic and structural analyses of the Western European Variscan Belt (WEVB) suggest that the most viable kinematic model for Variscan deformation in northern Iberia is oroclinal bending of an originally linear belt in a two-stage tectonic history. This history represents two regional compression phases (E-W in the Late Carboniferous and N-S in the Permian, both in present-day coordinates), which resulted in the refolding (about steeply plunging axes) of initially north-south trending thrusts and folds in the hinge zone, and oroclinal tightening due to vertical axis rotation of the belt's limbs. However, the orocline model has yet to be critically tested …

Morphologic Features Of Conduits And Aquifer Response In The Unconfined Floridan Aquifer System, West Central Florida, Lee J. Florea, H L. Vacher

Earth, Environmental, and Atmospheric Sciences Faculty Publications

Conduits within the unconfined Floridan Aquifer of west-central Florida include both horizontal and vertical components. In this paper, we investigate each and propose theories based upon cave survey data and a collection of over 300 Florida cave maps. First, we find that vertical portions of conduits visually correlate to fractures, and these fractures tend to be the dominant control of conduit directionality. Length-weighted rose diagrams of passage directions reveal a NW-SE and NE-SW pattern of conduit directions statistically similar to results found in remote sensing studies of photolinears. Secondly we note that horizontal elements of conduits occur at consistent horizons …

Seasonal Sediment Transport And Unusually Large Spit Development At Sandy Point, San Salvador, Bahamas, Vincent J. Voegeli, Alicia L. Simonti, H. Allen Curran

Geosciences: Faculty Publications

Reprinted from: R.L. Davis & D. Gamble, eds., Proceedings of the 12th Symposium on the Geology of the Bahamas and Other Carbonate Regions, San Salvador, Gerace Research Center

Petrogenesis Of Pleistocene Basalts In The Norris-Mammoth Corridor, Yellowstone National Park, Kristeen Marie Bennett

UNLV Theses, Dissertations, Professional Papers, and Capstones

The basalts of the Norris-Mammoth corridor within the Yellowstone Plateau volcanic field have an outcrop erupted volume of ~94 km³. Basalt in the Yellowstone Plateau volcanic field is minor in volume compared to 3,700 km³ of felsic lavas, domes, and pyroclastic rocks. The tholeiitic eruptive products formed small Hawaiian-style shield volcanoes. A newly identified volcanic vent, called the Panther Creek vent, within the Swan Lake Flat basalt stratigraphic unit, was primarily Strombolian in its eruption style. This vent is the first recognized cinder cone in Yellowstone National Park.

All basaltic units within the Norris-Mammoth corridor, and the …