Open Access. Powered by Scholars. Published by Universities.®

Geology Commons™

Open Access. Powered by Scholars. Published by Universities.®

Theses and Dissertations

Discipline
Institution
Keyword
Publication Year

Articles 271 - 300 of 626

Full-Text Articles in Geology

Correlation Of Electron Donor Concentrations In Sediments With Sediment Properties: New Providence, Iowa, Bijesh Maharjan Jan 2008

Correlation Of Electron Donor Concentrations In Sediments With Sediment Properties: New Providence, Iowa, Bijesh Maharjan

Theses and Dissertations

The concentrations of electron donors in aquifer sediments are important in understanding the fate and transport of redox-sensitive constituents in ground water, such as nitrate. In this study, 50 sediment samples were collected from below the water table from 11 boreholes at the US Geological Survey Agricultural Chemicals Transport site near New Providence, Iowa. All samples were analyzed for gravel, sand (coarse, medium, and fine), silt, clay, inorganic carbon contents and for the following electron donors: organic carbon, ferrous iron, and inorganic sulfide. A subset of sediment samples was analyzed for organic sulfur, but all of the 14 samples were …


Using Elliptical Fourier Analysis To Compare Size Of Morphospace Occupation Between Modern Edentulous Freshwater Unionoid Mussels And The Fossils At L6516 (Slope County, North Dakota, Usa), With Remarks On Preservation, Mathew E. Burton-Kelly Jan 2008

Using Elliptical Fourier Analysis To Compare Size Of Morphospace Occupation Between Modern Edentulous Freshwater Unionoid Mussels And The Fossils At L6516 (Slope County, North Dakota, Usa), With Remarks On Preservation, Mathew E. Burton-Kelly

Theses and Dissertations

The purpose of this project was to use outline morphometric techniques to determine the number of freshwater mussel taxa present at locality L6516 (“Das Goods”),which is located in Cretaceous strata in the basal Ludlow Member of the Fort Union Formation in Slope County, North Dakota, U.S.A. Secondary goals were to improve the outline morphometric procedures that have been previously used to characterize fossil and extant freshwater mussels, and to describe in more detail the preservation of the edentulous unionoid specimens from the Das Goods area.

Outlines of individual mussel valves were used for morphometric analyses due to lack of preserved …


A Stratigraphic And Depositional Interpretation Of A Sand Quarry In Middle Georgia, Jessica Taylor Jan 2008

A Stratigraphic And Depositional Interpretation Of A Sand Quarry In Middle Georgia, Jessica Taylor

Theses and Dissertations

Analysis of sediments from two sand quarries in Mauk, Georgia indicate braided stream environment. Sediment samples of both Pleistocene and Cretaceous age were collected, sedimentary features such as trough cross-bedding along with laminar bedding were recorded, and photos were taken to document the scale and stratigraphic sequences of the sediments. Petrified wood was collected throughout the two sand quarries indicating a terrestrial origin. Post-depositional modifications seen at some of sites include load and flame structures. Sediment samples were examined for grain-size distributions and other sediment textures.


Geochemical Analysis Of Ironstone Preserved Molluscan Fossils Of The Hell Creek Formation (Cretaceous) And Ludlow Member Of The Fort Union Formation (Paleogene) Of Southwestern North Dakota, Tanya P. Justham Jan 2008

Geochemical Analysis Of Ironstone Preserved Molluscan Fossils Of The Hell Creek Formation (Cretaceous) And Ludlow Member Of The Fort Union Formation (Paleogene) Of Southwestern North Dakota, Tanya P. Justham

Theses and Dissertations

The uppermost Cretaceous Hell Creek Formation and Paleocene Ludlow Member of the Fort Union Formation in easternmost Montana and western North Dakota produce ironstone preserved freshwater molluscan fossils. Ironstone preserved mollusks are associated with ironstone nodules, which have been described as composed of iron carbonate, iron oxide, or manganese oxide by various researchers. To date, the exact composition of the ironstone preservation has not been satisfactorily determined to allow agreement between researchers. Freshwater mollusk fossils, preserved as ironstone external casts, molds, and steinkerns, tend to be highly weathered. The poor preservation of the fossils has resulted in little professional interest, …


The Rate And Timing Of Direct Mountain Front Recharge In An Arid Environment, Silver Island Mountains, Utah, Gregory T. Carling Dec 2007

The Rate And Timing Of Direct Mountain Front Recharge In An Arid Environment, Silver Island Mountains, Utah, Gregory T. Carling

Theses and Dissertations

Direct mountain front recharge (MFR), water table recharge at the base of the mountain front, was evaluated on the arid (<250 mm/yr precipitation) Silver Island Mountains by comparing mountain precipitation to groundwater response. Direct MFR contributions were assessed on two catchments, one bedrock (i.e., mountain block) dominated and the other alluvial fan (i.e., mountain front) dominated. Catchment precipitation and shallow groundwater levels at each catchment outlet were measured for a 24 month period beginning October 2005. This time period captured one complete hydrologic cycle (December 2005-February 2007) for which annual and seasonal direct MFR rates were calculated. Annual direct MFR was calculated using a modified version of the water table fluctuation (WTF) method as 0.015-0.016% of precipitation on both catchments, with seasonal variations of 0% in summer up to 0.023% in winter, spring and fall. Seasonal direct MFR contributions are similar on the bedrock and the alluvial fan dominated catchments, with a notable exception during fall 2006 when direct MFR was twice as effective on the bedrock dominated system than on the alluvial fan dominated system (0.022% and 0.011% of precipitation, respectively). Darcy's law calculations show similarly low annual direct MFR contributions (0.013-0.032% of precipitation) as those calculated by the WTF method. Calculated direct MFR is 10% or less than typical calculated combined MFR (near surface recharge and deep underflow from the mountain block) for similar terrains and climates, and is only 3.5% of the combined MFR for the Silver Island Mountains as calculated by the Maxey-Eakin model. However, based on total recharge to the adjacent playa, it is apparent that the Maxey-Eakin model overestimates combined MFR, and the small calculated direct MFR is at least 50% of combined MFR. Despite some uncertainty in the numerical results, several patterns are evident in the data. The data show that direct MFR occurs in response to small rainfall events throughout much of the year, and that snowmelt is not necessary to produce direct MFR. The data also show that direct MFR responds more quickly and flushes through the system faster on the alluvial fan catchment than on the bedrock catchment.


An Approach To Mapping Of Shallow Petroleum Reservoirs Using Integrated Conventional 3d And Shallow P- And Sh-Wave Seismic Reflection Methods At Teapot Dome Field In Casper, Wyoming, Anita Onohuome Okojie-Ayoro Nov 2007

An Approach To Mapping Of Shallow Petroleum Reservoirs Using Integrated Conventional 3d And Shallow P- And Sh-Wave Seismic Reflection Methods At Teapot Dome Field In Casper, Wyoming, Anita Onohuome Okojie-Ayoro

Theses and Dissertations

Using the famous Teapot Dome oil field in Casper, Wyoming, USA as a test case, we demonstrate how high-resolution compressional (P) and horizontally polarized shear (SH) wave seismic reflection surveys can overcome the limitations of conventional 3D seismic data in resolving small-scale structures in the very shallow subsurface (< 100-200 m (~328-656 ft)). We accomplish this by using small CMP intervals (5 ft and 2.5 ft, respectively) and a higher frequency source. The integration of the two high-resolution seismic methods enhances the detection and mapping of fine-scale deformation and stratigraphic features at shallow depth that cannot be imaged by conventional seismic methods. Further, when these two high-resolution seismic methods are integrated with 3D data, correlated drill hole logs, and outcrop mapping and trenching, a clearer picture of both very shallow reservoirs and the relationship between deep and shallow faults can be observed. For example, we show that the Shannon reservoir, which is the shallowest petroleum reservoir at Teapot Dome (depth to the top of this interval ranging from 76-198 m (250-650 ft)) can only be imaged properly with high-resolution seismic methods. Further, northeast-striking faults are identified in shallow sections within Teapot Dome. The strike of these faults is approximately orthogonal to the hinge of Teapot Dome. These faults are interpreted as fold accommodation faults. Vertical displacements across these faults range from 10 to 40 m (~33 to 131 ft), which could potentially partition the Shannon reservoir. The integration of 3D and high-resolution P-wave seismic interpretation helped us determine that some of the northeast-striking faults relate to deeper faults. This indicates that some deeper faults that are orthogonal to the fold hinge cut through the shallow Shannon reservoir. Such an observation would be important for understanding the effect on fluid communication between the deep and shallow reservoirs via these faults. Furthermore, the high-resolution seismic data provide a means to better constrain the location of faults mapped from drill hole logs. Relocation of theses faults may require re-evaluation of well locations as some attic oil may have not been drained in some Shannon blocks by present well locations. Therefore our study demonstrates how conventional 3D seismic data require additional seismic acquisition at smaller scales in order to image deformation in shallow reservoirs. Such imaging becomes critical in cases of shallow reservoirs where it is important to define potential problems associated with compartmentalization of primary production, hazard mitigation, enhanced oil recovery, or carbon sequestration.


Seismic And Well Log Attribute Analysis Of The Jurassic Entrada/Curtis Interval Within The North Hill Creek 3d Seismic Survey, Uinta Basin, Utah, A Case History, Ryan J. Oneal Jul 2007

Seismic And Well Log Attribute Analysis Of The Jurassic Entrada/Curtis Interval Within The North Hill Creek 3d Seismic Survey, Uinta Basin, Utah, A Case History, Ryan J. Oneal

Theses and Dissertations

3D seismic attribute analysis of the Jurassic Entrada/Curtis interval within the North Hill Creek (NHC) survey has been useful in delineating reservoir quality eolian-influenced dune complexes. Amplitude, average reflection strength and spectral decomposition appear to be most useful in locating reservoir quality dune complexes, outlining their geometry and possibly displaying lateral changes in thickness. Cross sectional views displaying toplap features likely indicate an unconformity between Entrada clinoforms below and Curtis planar beds above. This relationship may aid the explorationist in discovering this important seismic interval. Seismic and well log attribute values were cross plotted and have revealed associations between these …


Microfacies Analysis, Sedimentary Petrology, And Reservoir Characterization Of The Sinbad Limestone Based Upon Surface Exposures In The San Rafael Swell, Utah, Caleb R. Osborn Jul 2007

Microfacies Analysis, Sedimentary Petrology, And Reservoir Characterization Of The Sinbad Limestone Based Upon Surface Exposures In The San Rafael Swell, Utah, Caleb R. Osborn

Theses and Dissertations

The Lower Triassic Sinbad Limestone Member of the Moenkopi Formation has produced minor amounts of oil in the Grassy Trail Creek field near Green River, Utah and is present below much of central Utah including the recently discovered Covenant field. Superb outcrops of this thin (15 m), mixed carbonate-silicilastic unit in the San Rafael Swell permit detailed analysis of its vertical and lateral reservoir heterogeneity. Vertically, the Sinbad Limestone comprises three facies associations: (A) a basal storm-dominated, well-circulated skeletal-oolitic-peloidal limestone association, (B) a storm-dominated, poorly-circulated hummocky cross-stratified siliciclastic/peloidal association, and (C) a capping peritidal cross-bedded oolitic dolograinstone association. Eleven microfacies …


The Smallest Base And Precious Metal Deposits In The World: Vapor Transport And Deposition Of Co-Cu-Sn-Ag Alloys In Vesicles, Elizabeth Adele Outdoor Hunter Jul 2007

The Smallest Base And Precious Metal Deposits In The World: Vapor Transport And Deposition Of Co-Cu-Sn-Ag Alloys In Vesicles, Elizabeth Adele Outdoor Hunter

Theses and Dissertations

Metallic bronze-Co-Ag alloys ranging from1-90 µm have been discovered in bomb and lava vesicles from the mafic volcanoes of Kilauea in Hawaii and Vesuvius, Stromboli and Etna in Italy. It is inferred that the metals for these alloys were transported (in part) as chloride complexes, and that the metal ratios in the alloys may be a function of S/Cl. Alloy compositions in each system are extremely heterogeneous with Co concentrations from 1% to 94%, Cu from 2% to 89%, Sn from 1% to 22% and Ag from 0.5% to 42%. Maximum abundances (in wt%) of other trace or minor elements …


Reservoir Characterization And Outcrop Analogs To The Navajo Sandstone In The Central Utah Thrust Belt Exploration Play, Ashley Dalrymple Jul 2007

Reservoir Characterization And Outcrop Analogs To The Navajo Sandstone In The Central Utah Thrust Belt Exploration Play, Ashley Dalrymple

Theses and Dissertations

Reservoir heterogeneity plays an important role in oil field economics and completion strategies. We herein characterize the reservoir heterogeneity of the Early Jurassic Navajo Sandstone in the Justensen Flat/Devils Canyon area of the San Rafael Swell, Utah. These outcrops are located approximately 60 kilometers (45 mi) east of the recently discovered Covenant oil field which is located in the central Utah thrust belt exploration play. The reservoir for the Covenant field is the Navajo Sandstone. This study can serve as an outcrop analogue for this developing play and other eolian reservoirs worldwide. There are eight facies within the Navajo Sandstone …


Mapping Middle Paleozoic Erosional And Karstic Patterns With 3-D Seismic Attributes And Well Data In The Arkoma Basin, Oklahoma, Alonzo R. Brinkerhoff Jun 2007

Mapping Middle Paleozoic Erosional And Karstic Patterns With 3-D Seismic Attributes And Well Data In The Arkoma Basin, Oklahoma, Alonzo R. Brinkerhoff

Theses and Dissertations

Newly available industry well data and seismic attribute analysis reveal that late Ordovician-early Devonian Hunton Group strata are more widespread (i.e., not removed by mid-Devonian erosion) in the central and southern portions of the Arkoma Basin in eastern Oklahoma than previously thought. This study demonstrates the value of applying seismic attribute analysis to problems of quantifying and mapping stratigraphic features caused by erosions and/or karstification. Well and seismic isochron data in the Red Oak petroleum field for the Viola-Woodford interval (the units that lie stratigraphically beneath and above, respectively, the Huton Group) show isolated ~40-m thick lenses of Hunton rocks, …


Origin And Tectonic Evolution Of Gondwana Sequence Units Accreted To The Banda Arc: A Structural Transect Through Central East Timor, Elizabeth Anick Zobell May 2007

Origin And Tectonic Evolution Of Gondwana Sequence Units Accreted To The Banda Arc: A Structural Transect Through Central East Timor, Elizabeth Anick Zobell

Theses and Dissertations

Petrographic and age analysis of sandstones, detailed structural analysis and gravity modeling were conducted to investigate the origin of the Gondwana Sequence in the Timor Region, and to better constrain the tectonic evolution of the active Banda Arc. Our field studies and U/Pb zircon age analysis helped assign most units to either Asian or Australian affinity. Detrital zircon from uplifted Banda forearc units (Asian affinity) have U/Pb ages as young as 80 Ma (Standley and Harris, in press). In contrast, analysis of detrital zircon from Gondwana Sequence sandstones accreted to the Banda Arc from Savu to East Timor are no …


Solute Chemistry And Isotopic Investigation Of The Groundwater Flow Paths In Honey Lake Basin, Lassen County, California And Washoe County, Nevada, Rachel M. Henderson Mar 2007

Solute Chemistry And Isotopic Investigation Of The Groundwater Flow Paths In Honey Lake Basin, Lassen County, California And Washoe County, Nevada, Rachel M. Henderson

Theses and Dissertations

Honey Lake Basin is a large, hydrologically closed valley with two playa lakes that are separated by a low elevation sill. The Basin has a complex hydrogeologic setting, with numerous groundwater flow paths that interact with surface waters and three basic aquifers; shallow, deep, and geothermal. Thirteen flow paths; eleven cold and two thermal, are identified and the geochemical evolution of those paths are characterized by integrating solute chemistry and isotopic data. The chemical flow paths include recharge in either granitoid or volcanic terrains in the Sierra Nevada Range and the Modoc Plateau, respectively. The groundwater then flows through alluvial …


Pre-Historic Landslides On The Southeast Flank Of The Uinta Mountains, Utah: Character And Causes Of Slope Failure, Todd D. Bradfield Mar 2007

Pre-Historic Landslides On The Southeast Flank Of The Uinta Mountains, Utah: Character And Causes Of Slope Failure, Todd D. Bradfield

Theses and Dissertations

More than 100 landslides have been mapped along the southeast flank of the Uinta Mountains. Large landslide deposits are up to 4.6 kilometers long and have an area of approximately 5-9 km². Landslide types include multiple and successive rock slumps, debris slumps and debris flows. Most landslides have a main head scarp in the Bishop Conglomerate and the large landslides have many minor scarps. Multiple slump blocks are manifest by repeated transverse ridges and trenches in the head area of some landslides. Most body and toe areas are deeply incised by gully erosion (up to 91 meters deep) and drainages …


Structural Analysis Of Rock Canyon Near Provo, Utah, Laura Cardon Wald Mar 2007

Structural Analysis Of Rock Canyon Near Provo, Utah, Laura Cardon Wald

Theses and Dissertations

A detailed structural study of Rock Canyon (near Provo, Utah) provides insight into Wasatch Range tectonics and fold-thrust belt kinematics. Excellent exposures along the E-W trending canyon allow the use of digital photography in conjunction with traditional field methods for a thorough analysis of Rock Canyon's structural features. Detailed photomontages and geometric and kinematic analyses of some structural features help to pinpoint deformation mechanisms active during the canyon's tectonic history. Large-scale images and these structural data are synthesized in a balanced cross section, which is used to reconstruct the structural evolution of this portion of the range. Projection of surficial …


The Origins Of Four Paterae Of Malea Planum, Mars, Susan K. Larson Mar 2007

The Origins Of Four Paterae Of Malea Planum, Mars, Susan K. Larson

Theses and Dissertations

Malea Planum is a volcanic plain on the southern rim of Hellas Planitia, the largest impact basin on Mars. Four large circular structures on Malea Planum have traditionally been identified as paterae, or low relief, central vent volcanoes (Plescia and Saunders, 1979). A geologic map was constructed and new crater counts made to explore the ages and origins of the paterae. Amphitrites and Peneus Paterae have radial patterns of wrinkle ridges on their flanks and distinct summit calderas (95 km and 130 km across) with arcuate bounding scarps. In contrast, Malea and Pityusa Paterae are broad depressions with diameters greater …


Banda Forearc Metamorphic Rocks Accreted To The Australian Continental Margin: Detailed Analysis Of The Lolotoi Complex Of East Timor, Carl Eldon Standley Jan 2007

Banda Forearc Metamorphic Rocks Accreted To The Australian Continental Margin: Detailed Analysis Of The Lolotoi Complex Of East Timor, Carl Eldon Standley

Theses and Dissertations

Petrologic, structural and age investigations of the Lolotoi Complex of East Timor indicate that it is part of a group of thin metamorphic klippen found throughout the region that were detached from the Banda forearc and accreted to the NW Australian continental margin during Late Miocene to Present arc-continent collision. Metamorphic rock types are dominated by (in order of greatest to least abundance), greenschist, graphitic phyllite, quartz-mica schist, amphibolite and pelitic schist. Mineral, whole rock, and trace element geochemical analyses of metabasites indicate that protolith compositions are consistent with tholeiitic basalt and basaltic andesite with mixed MORB and oceanic arc …


Resolving Terrain Effects In Borehole Temperature Profiles, Shannon M. Heinle Jan 2007

Resolving Terrain Effects In Borehole Temperature Profiles, Shannon M. Heinle

Theses and Dissertations

The study of borehole paleoclimatology aids scientists in determining past climate changes and in understanding current climate trends. Accurate borehole temperature logs are necessary to obtain a useful temperature profile. However, as many climate workers have discovered, borehole temperature profiles can have many causes of inaccuracy. Uncertainties associated with borehole data include errors stemming from temperature measurement, depth measurement, thermophysical property measurements, and terrain effects. Terrain effects include topography, changes in land cover over time, direct and diffused sun radiation, and groundwater flow.

This study focused on specific terrain effects influencing borehole temperature profiles in the United States borehole dataset …


Methane Potential Of Upper Fort Union Formation Sandstones, Campbell County, Wyoming, Michael J. Blackstone Jan 2007

Methane Potential Of Upper Fort Union Formation Sandstones, Campbell County, Wyoming, Michael J. Blackstone

Theses and Dissertations

Coalbed methane has been produced from the coalbeds of the Upper Fort Union Formation in the Powder River Basin for many years. The sandstones associated with these coals have also proven to be gas-charged, but industry has done little with the sandstones thus far. The purpose of this study is to determine the paleoenvironrnent responsible for the deposition of the coal and sandstone bodies in an attempt to locate gas-charged sandstone bodies in the Tongue River Member of the Fort Union Formation.

The 30-mile by 90-mile study area was chosen because of the presence of a decrease in thick coalbed …


Developing A Rapid Method For Assessing The Physical Stability Of Streams In Minnesota's Agassiz Beach Ridges, Abigail V. Franklund Jan 2007

Developing A Rapid Method For Assessing The Physical Stability Of Streams In Minnesota's Agassiz Beach Ridges, Abigail V. Franklund

Theses and Dissertations

This thesis assessed the physical characteristics and stability of selected western Minnesota streams that cross the eastern beach ridges of glacial Lake Agassiz. Stream and river channels in this area host unusually diverse aquatic habitat and biodiversity, but incompatible land use along channels and in watersheds impair their quality and function. Previous rapid assessment protocols have been developed for stream attributes and stability, but these methods have been developed elsewhere in the United States and are not necessarily appropriate for western Minnesota’s unique geology and landscape.

A rapid reconnaissance method was developed to assess stream conditions using an integrated numerical …


Petrogenesis Of Eocene-Oligocene Magmatism Of The Sulphur Springs Range, Central Nevada: The Role Of Magma Mixing, Elizabeth Balls Ryskamp Nov 2006

Petrogenesis Of Eocene-Oligocene Magmatism Of The Sulphur Springs Range, Central Nevada: The Role Of Magma Mixing, Elizabeth Balls Ryskamp

Theses and Dissertations

Widespread base- and precious-metal anomalies, altered porphyry intrusions and oxidized veins occur in a portion of the Sulphur Springs Range, Nevada (adjacent to the Au-producing Carlin Trend). Some of the Eocene-Oligocene intrusions and cogenetic volcanic rocks in the range exhibit evidence of magma mixing and invite comparisons with other mineralized, Eocene mixed magma systems like the Bingham porphyry Cu deposit 300 km farther to the east. The Sulphur Springs igneous suite ranges compositionally through rhyolite, dacite, andesite and basaltic andesite but is less alkaline than the Bingham volcanic suite. However, the alkali content of the Sulphur Springs suite is similar …


Garnetites Of The Cardigan Pluton - Evidence For Restite And Implications For Source Rock Compositions., Teresa K. Pett Nov 2006

Garnetites Of The Cardigan Pluton - Evidence For Restite And Implications For Source Rock Compositions., Teresa K. Pett

Theses and Dissertations

The Cardigan pluton, located in the southern half of New Hampshire, is a strongly peraluminous, S-type granite which is granodioritic in composition. It is inferred to have been emplaced rapidly, thrust up along west-verging nappes during the Acadian orogeny. Distinctive pods, consisting of 50 to 70 percent modal garnet, are found throughout the pluton in assemblages of garnet + sillimanite + biotite + plagioclase + quartz. These garnetite rocks present an intriguing case for restite. Textural features of the garnetite rocks, such as fibrolitic sillimanite mats and flat, unzoned major and trace-element garnet grain profiles, provide evidence for biotite dehydration …


Detection Of A Landslide Glide Plane Using Seismic Reflection Methods: Investigation At Little Valley Landslide In Draper, Utah, Brady E. Tingey Sep 2006

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 …


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 Jul 2006

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, …


A Stratigraphic And Geochronologic Analysis Of The Morrison Formation/Cedar Mountain Formation Boundary, Utah, Brent W. Greenhalgh Jul 2006

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 …


Geologic Map And Structural Analysis Of The Twin Rocks 7.5 Minute Quadrangle, Wayne County, Utah, Samuel C. Sorber Jun 2006

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 …


Mineral-Scale Sr Isotopic Study Of Plagioclase In The Mafic Dikes Of The North American Wall And The Diorite Of The Rockslides, Yosemite Valley, California., Wendy Rae Nelson Mar 2006

Mineral-Scale Sr Isotopic Study Of Plagioclase In The Mafic Dikes Of The North American Wall And The Diorite Of The Rockslides, Yosemite Valley, California., Wendy Rae Nelson

Theses and Dissertations

The North American Wall mafic dikes and the diorite of the Rockslides mafic complex in the intrusive suite of Yosemite Valley show evidence of mixing with their host granites as well as with earlier components. Whole rock major element variation diagrams indicate the mafic rocks mixed with a more silicic component, but extrapolating to the silica end member does not yield the same result with each element. Trace element concentrations show a wide variation in concentration of Cr and Ni, with two samples showing enrichment in Cr (>300 ppm) and Ni (~44 ppm) compared to other samples (Cr =13-94 …


A Multidisciplinary Approach To Reservoir Characterization Of The Coastal Entrada Erg-Margin Gas Play, Utah, Will D. Monn Mar 2006

A Multidisciplinary Approach To Reservoir Characterization Of The Coastal Entrada Erg-Margin Gas Play, Utah, Will D. Monn

Theses and Dissertations

World-class outcrops of an outermost erg-margin can be observed within the Middle Jurassic Entrada Sandstone near Capitol Reef National Park, Utah. These erg-margin deposits contain isolated reservoir quality sandstone bodies that transition into a muddy tidal flat facies. These high quality reservoirs are dominated by eolian-influenced facies interbedded with sandy interdune facies. They are sealed vertically by muddy and silty facies of associated tidal flat deposits that act as excellent stratigraphic traps in the subsurface. A variety of approaches were used to characterize these Entrada erg-margin reservoirs including: annotated panoramas of outcrops, measured sections, scintillometer measurements of field sections, facies …


Unresolved Problems Involving The Hydrogeology And Sequence Stratigraphy Of The Wasatch Plateau Based On Mapping Of The Wattis 7.5 Minute Quadrangle, Carbon And Emery Counties, Utah: Insights Gained From A New Geologic Map, David O. Alderks Mar 2006

Unresolved Problems Involving The Hydrogeology And Sequence Stratigraphy Of The Wasatch Plateau Based On Mapping Of The Wattis 7.5 Minute Quadrangle, Carbon And Emery Counties, Utah: Insights Gained From A New Geologic Map, David O. Alderks

Theses and Dissertations

The Wattis 7.5 Minute Quadrangle is located in central Utah, in the transition zone between the Basin and Range province and the Colorado plateau. Two small grabens, located in the quadrangle, are the easternmost evidence of Basin and Range faulting. Sedimentary units exposed are mainly Cretaceous in age and deposited in the Western Cretaceous Interior Seaway. This area is of economical importance due to its large coal deposits, coal bed methane, and groundwater. The Wattis Quadrangle provided an ideal opportunity to test, at a small scale, the applicability of a new groundwater model for stratified mountainous terranes. Water samples had …


Modeling Groundwater Denitrification By Ferrous Iron Using Phreeqc, Tedros Tesfay Jan 2006

Modeling Groundwater Denitrification By Ferrous Iron Using Phreeqc, Tedros Tesfay

Theses and Dissertations

Nitrate is one of the most common groundwater contaminants, and ingesting it leads to potential health risks. Denitrification, the only effective process to eliminate nitrate, is limited by the abundance of biologically available electron donors. Thus, understanding the natural denitrification capacity of aquifers, through the analysis of all the major electron donors, is essential.

A better way to estimate groundwater denitrification reactions is to compute the mass balance of the redox sensitive species. The University of North Dakota (UND) denitrification team installed mesocosms (ISMs) to understand the fate of nitrate in field conditions. Accordingly, the team has shown the significant …