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Stratigraphic And Structural Analysis Of Coals In The Ferron Sandstone Member Of The Mancos Shale And Fruitland Formation: Relationship To Coal Reservoir Permeability And Coalbed Methane Production, Jason Lynn Kneedy May 2005

Stratigraphic And Structural Analysis Of Coals In The Ferron Sandstone Member Of The Mancos Shale And Fruitland Formation: Relationship To Coal Reservoir Permeability And Coalbed Methane Production, Jason Lynn Kneedy

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

Coal reservoir quality in the Ferron Sandstone Member of the Mancos Shale, and in the Fruitland Formation is dependent on coal cleat characteristics. Coal reservoir permeability increases as a result of high cleat density. From careful outcrop examination, we were able to identify several factors that increase cleat density. Vitrain coal typically has the highest fracture density as a result of having well-developed face cleats and conchoidal fractures. Clarain coal contains face and butt cleats. Cleat density in clarain is also controlled by mechanical layer thickness. As mechanical layer thickness decreases, cleat density increases. Durain and fusain coals typically contain …


Characterizing Deformation, Damage Parameters, And Clay Composition In Fault Zones: Insights From The Chelungpu Thrust, Taiwan, And Mozumi Right Lateral Fault, Japan, Angela J. Isaacs May 2005

Characterizing Deformation, Damage Parameters, And Clay Composition In Fault Zones: Insights From The Chelungpu Thrust, Taiwan, And Mozumi Right Lateral Fault, Japan, Angela J. Isaacs

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

The Chelungpu thrust fault, Taiwan, and the Mozumi right-lateral fault, Japan, provide an opportunity to characterize active faults in clastic sedimentary rocks and provide constraints to seismologic models. The northern Chelungpu fault has a 10-30 m wide primary damage zone characterized by dense fractures and chemical alteration. The southern Chelungpu fault has a 25-70 m wide primary damage zone characterized by dense fractures, alteration, intensely sheared rock, and secondary faults. The complexity of the damage zone, geochemistry, and clay mineralogy of the southern fault zone reflects its greater maturity (~1 Ma) relative to the northern fault zone (~46-100 Ka). A …


Humic And Fulvic Acids: Effects On Plant Nutrition And Growth, Jason Tew May 2005

Humic And Fulvic Acids: Effects On Plant Nutrition And Growth, Jason Tew

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

Humic substances are reported to improve plant growth and nutrient uptake, with iron the most studied nutrient. The most common forms of iron in soils are iron oxides, which are stable under aerobic conditions and unavailable for plant uptake. Iron deficient plants become chlorotic, which reduces growth and yield. To determine if humic substances can reduce iron chlorosis, five commercially available organic acids were tested on maize grown in sand columns at high pH. The dry granular humic acid from Aldrich Chemical Company applied at 84.4 g/liter of sand by volume (5% by mass) and 1 g/liter added with irrigation …


Relating Bedrock Strength To Hydraulic Driving Forces Along The Large-Scale Profile Of The Colorado River In Glen And Grand Canyons, Rob D. Mackley May 2005

Relating Bedrock Strength To Hydraulic Driving Forces Along The Large-Scale Profile Of The Colorado River In Glen And Grand Canyons, Rob D. Mackley

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

The role of bedrock on the longitudinal profile of the Colorado River has intrigued workers for over a century. The river's profile exhibits large-scale (10 to 100 km) variations in geomorphology that are qualitatively associated with changes in rock type. This study provides the first bedrock-strength data to quantitatively test the relation of bedrock-resisting to hydraulic-driving forces in Glen and Grand canyons. The intent of this study is to explore the role, if any, that bedrock has on large-scale geomorphic variations along the profile of the Colorado River. Rock-strength data collected at 84 sites along the river corridor in Glen …


The Quaternary Tectonic And Structural Evolution Of The San Felipe Hills, California, Stefan M. Kirby May 2005

The Quaternary Tectonic And Structural Evolution Of The San Felipe Hills, California, Stefan M. Kirby

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

We examine the transition between extension and strike-s lip in the San Felipe Hills, western Salton Trough, southern California using new and compiled geologic mapping, measured stratigraphic sections, magnetostratigraphy, and structural analysis. A 625 m measured section describes the Borrego, Ocotillo , and Brawley formations in the SE San Felipe Hills and constrains a regional disconformity and correlative angular unconformity at ~ 1 Ma. Sedimentation rates for the Brawley Formation above the disconformity range from 1.0 to 1.2 mm/yr, palcoflow was to the ENE. The Brawley Formation consists of three interbeddcd lithofac ics; (I) fluvial and fluvio-d eltaic, (2) lacustrinc, …


The Quaternary Stratigraphy Of The Henrys Fork And Western Browns Park, Northeastern Uinta Mountains, Utah And Wyoming, Ronald C. Counts May 2005

The Quaternary Stratigraphy Of The Henrys Fork And Western Browns Park, Northeastern Uinta Mountains, Utah And Wyoming, Ronald C. Counts

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

The landscape evolution of the northeastern Uinta Mountains and the manner in which climatic and tectonic forcing have influenced it are not well constrained. Surficial deposits covering ~325 km2 below the glacial termini in the Henrys Fork and ~50 km2 along the Green River in western Browns Park were mapped at 1:24,000 scale to develop a Quaternary stratigraphic framework for the northeastern Uinta Mountains.

The Henrys Fork mapping area spans from late Wisconsinan moraines to Flaming Gorge Reservoir. The Henrys Fork stratigraphy contains 10 mainstem gravels, six piedmont gravels, and landslide deposits. Terraces preserved along the Henrys Fork …


Geochronology Of Hemphillian-Blancan Aged Strata, Guanajuato, Mexico, And Implications For Timing Of The Great American Biotic Interchange, Bart J. Kowallis, John J. Flynn, Clarita Nunez, Oscar Carranza-Castaneda, Wade E. Miller, Carl C. Swisher Iii, Everett Lindsay May 2005

Geochronology Of Hemphillian-Blancan Aged Strata, Guanajuato, Mexico, And Implications For Timing Of The Great American Biotic Interchange, Bart J. Kowallis, John J. Flynn, Clarita Nunez, Oscar Carranza-Castaneda, Wade E. Miller, Carl C. Swisher Iii, Everett Lindsay

Faculty Publications

We present new geochronologic magnetostratigraphy, fission-track and 40Ar/39Ar radioisotopic dates, biostratigraphy)bdata constraining the age of three separate sequences and a composite section from Guanajuato, Mexico. Those data make this one of the most complete and precisely age-calibrated sequences in North America spanning the Hemphillian/Blancan North American Land Mammal “Age” (NALMA) boundary interval, and the data further constrain the timing and pattern of the Great American Biotic Interchange (GABI). In total, 196 samples (77 sites) were used to construct the magnetic polarity stratigraphies, with eight fission-track analyses and four new 40Ar/39Ar radioisotopic dates. The sections sampled are possibly latest Miocene to …


Hydrology Of Vernal Pools At Three Sites, Southern Sacramento Valley, Robert J. Williamson, Graham E. Fogg, Mark C. Rains, Thomas H. Harter Apr 2005

Hydrology Of Vernal Pools At Three Sites, Southern Sacramento Valley, Robert J. Williamson, Graham E. Fogg, Mark C. Rains, Thomas H. Harter

School of Geosciences Faculty and Staff Publications

The subsurface hydrology of vernal pools at three vernal pool complexes was investigated during three wet seasons in 2002-2004. The complexes were at Gridley Ranch, Valensin Ranch, and the Mather Field in northern California. The selected complexes provided variation in soils, landforms and topography. Three vernal pools were chosen in each complex based on variation in pool type, size, and position in the drainage system. The objectives were to describe the subsurface hydrology of vernal pools to refine the conceptual model of vernal pool hydrology and to answer questions about: the size of watershed support for vernal pools, the importance …


Establising A High-Frequency Standard Reference Sequence Stratigraphy, Sea-Level Curve, And Biostratigraphy For Morrowan Strata Of The Lower Absaroka I Time Slice Based Upon The Bird Spring Formation, Arrow Canyon, Nevada, Kristen Phelps Briggs Apr 2005

Establising A High-Frequency Standard Reference Sequence Stratigraphy, Sea-Level Curve, And Biostratigraphy For Morrowan Strata Of The Lower Absaroka I Time Slice Based Upon The Bird Spring Formation, Arrow Canyon, Nevada, Kristen Phelps Briggs

Theses and Dissertations

For the same reasons which prompted its ratification in 1990 as the Global Stratotype Section and Point for the Mid-Carboniferous boundary, namely, section completeness, abundant fossils, and excellent exposure, the Morrowan Arrow Canyon Bird Spring strata is recommended as a candidate standard sequence stratigraphic reference for the Morrowan portion of the Lower Absaroka I supersequence. The stratigraphic architecture of Morrowan strata in Arrow Canyon was largely controlled by high-amplitude (100-m), high-frequency sea-level changes. Outcrop data and facies stacking patterns define 59 fifth-order fundamental cycles. These fundamental cycles stack into ten third-order sequences with an average duration of 320 ka. Changes …


Wave Field Migration As A Tool For Estimating Spatially Continuous Radar Velocity And Water Content In Glaciers, John H. Bradford, Joel T. Harper Apr 2005

Wave Field Migration As A Tool For Estimating Spatially Continuous Radar Velocity And Water Content In Glaciers, John H. Bradford, Joel T. Harper

CGISS Publications and Presentations

Normal-moveout velocity analysis can lead to significant overestimates of the velocity structure of temperate glaciers since most englacial reflectors approximate point scatters and violate the assumption of planar flat lying reflectors. Migration velocity analysis (MVA) is a tool that does not depend on the assumption of flat lying reflectors. MVA can provide laterally and vertically continuous velocity estimates from conventional common-offset radar sections. In a study of temperate Bench Glacier, Alaska, we used MVA coupled with dielectric modeling to estimate the distribution of water content along a cross-section of the glacier. We found the glacier has two layers, an upper …


Wave Field Migration As A Tool For Estimating Spatially Continuous Radar Velocity And Water Content In Glaciers, John H. Bradford, Joel T. Harper Apr 2005

Wave Field Migration As A Tool For Estimating Spatially Continuous Radar Velocity And Water Content In Glaciers, John H. Bradford, Joel T. Harper

Geosciences Faculty Publications

Normal-moveout velocity analysis can lead to significant overestimates of the velocity structure of temperate glaciers since most englacial reflectors approximate point scatters and violate the assumption of planar flat lying reflectors. Migration velocity analysis (MVA) is a tool that does not depend on the assumption of flat lying reflectors. MVA can provide laterally and vertically continuous velocity estimates from conventional common-offset radar sections. In a study of temperate Bench Glacier, Alaska, we used MVA coupled with dielectric modeling to estimate the distribution of water content along a cross-section of the glacier. We found the glacier has two layers, an upper …


Adoption Of Riparian Forest Buffers On Private Lands In Nebraska, Usa, Peter Skelton, Scott J. Josiah, James W. King, James R. Brandle, Glenn A. Helmers, Charles A. Francis Apr 2005

Adoption Of Riparian Forest Buffers On Private Lands In Nebraska, Usa, Peter Skelton, Scott J. Josiah, James W. King, James R. Brandle, Glenn A. Helmers, Charles A. Francis

Department of Agricultural Leadership, Education, and Communication: Faculty Publications

Pesticide and nutrient runoff from agricultural fields is a socio-environmental problem in the Midwestern United States. Riparian forest buffers (RFBs) are a proven conservation practice that effectively manage this problem, though adoption rates are low. A mail survey was conducted to determine differences between adopter and nonadopter characteristics and attitudes with regard to the use of RFBs. Data were collected from 48 RFB adopters and 261 RFB nonadopters in two Nebraska watersheds. Inferential and multivaririate statistics were used to identify differences between adapter status and producer status groups. About half (50.8%) the respondents were nonproducers. Nonproducers are agricultural landowners not …


Patterns Of Fish Use And Piscivore Abundance Within A Reconnected Saltmarsh Impoundment In The Northern Indian River Lagoon, Florida, Philip W. Stevens, Clay L. Montague, Kenneth J. Sulak Apr 2005

Patterns Of Fish Use And Piscivore Abundance Within A Reconnected Saltmarsh Impoundment In The Northern Indian River Lagoon, Florida, Philip W. Stevens, Clay L. Montague, Kenneth J. Sulak

United States Geological Survey: Staff Publications

Nearly all saltmarshes in east-central, Florida were impounded for mosquito control during the 1960s. The majority of these marshes have since been reconnected to the estuary by culverts, providing an opportunity to effectively measure exchange of aquatic organisms. A multi-gear approach was used monthly to simultaneously estimate fish standing stock (cast net), fish exchange with the estuary (culvert traps), and piscivore abundance (gill nets and bird counts) to document patterns of fish use in a reconnected saltmarsh impoundment. Changes in saltmarsh fish abundance, and exchange of fish with the estuary reflected the seasonal pattern of marsh flooding in the northern …


Lack Of Significant Changes In The Herpetofauna Of Theodore Roosevelt National Park, North Dakota, Since The 1920s, Blake R. Hossack, Paul Stephen Corn, David S. Pilliod Apr 2005

Lack Of Significant Changes In The Herpetofauna Of Theodore Roosevelt National Park, North Dakota, Since The 1920s, Blake R. Hossack, Paul Stephen Corn, David S. Pilliod

United States Geological Survey: Staff Publications

We surveyed 88 upland wetlands and 12 1-km river sections for amphibians in Theodore Roosevelt National Park, North Dakota, during 2001–2002 to gather baseline data for future monitoring efforts and to evaluate changes in the distribution of species. We compared our results to collections of herpetofauna made during 1920–1922, 1954 and 1978–1979. The boreal chorus frog (Pseudacris maculata) was the most common amphibian in upland wetlands, followed by the tiger salamander (Ambystoma tigrinum), Woodhouse’s toad (Bufo woodhousii), northern leopard frog (Rana pipiens), plains spadefoot (Spea bombifrons) and the Great Plains …


Geochemistry Of Serpentinized Peridotites From The Mariana Forearc Conical Seamount, Odp Leg 125: Implications For The Elemental Recycling At Subduction Zones, Ivan P. Savov, Jeffrey G. Ryan, Massimo D'Antonio, Katherine Kelley, Patrick Mattie Apr 2005

Geochemistry Of Serpentinized Peridotites From The Mariana Forearc Conical Seamount, Odp Leg 125: Implications For The Elemental Recycling At Subduction Zones, Ivan P. Savov, Jeffrey G. Ryan, Massimo D'Antonio, Katherine Kelley, Patrick Mattie

Geology Faculty Publications

Recent examinations of the chemical fluxes through convergent plate margins suggest the existence of significant mass imbalances for many key species: only 20–30% of the to-the-trench inventory of large-ion lithophile elements (LILE) can be accounted for by the magmatic outputs of volcanic arcs. Active serpentinite mud volcanism in the shallow forearc region of the Mariana convergent margin presents a unique opportunity to study a new outflux: the products of shallow-level exchanges between the upper mantle and slab-derived fluids. ODP Leg 125 recovered serpentinized harzburgites and dunites from three sites on the crests and flanks of the active Conical Seamount. These …


Producing Pulses In The Northern Agricultural Region, Peter White, Martin Harries, Mark Seymour, Pam Burgess Apr 2005

Producing Pulses In The Northern Agricultural Region, Peter White, Martin Harries, Mark Seymour, Pam Burgess

Bulletins 4000 -

Pulses, like most other temperate crops, are ideally suited to environments with mild temperatures, adequate rainfall and free draining soils that have a deep uniform profile, a medium to fine texture and slightly acid to neutral pH (6.5-7.5). Pulses when grown on these soils and in these environments produce reliable yields, are relatively easy to manage and achieve good returns on investment.

Pulses can be grown very successfully in less ideal situations, but must then be managed carefully to ensure reliable yields. The different pulse species, and even different varieties of the same species, vary in how tolerant they are …


Evidence Of Holocene Climate Change In A Nebraska Sandhills Wetland, Barbara Nicholson, James B. Swinehart Apr 2005

Evidence Of Holocene Climate Change In A Nebraska Sandhills Wetland, Barbara Nicholson, James B. Swinehart

Great Plains Research: A Journal of Natural and Social Sciences (through 2013)

The Nebraska Sandhills consist of 50,000 km2 of dunes, currently stabilized by vegetation. Radiocarbon dates of paleosols, blocked paleovalleys, and sand beds found in interdunal wetlands suggest that the Holocene had significant periods of dune reactivation. A paleoecological investigation was conducted in Jumbo Valley, NE, in an interdunal wetland known to contain sand layers interbedded with peat. The sedimentary record in two cores is continuous, except for some loss due to surficial burns. Macrofossils indicate that the late Pleistocene was cool and wet, with current vegetation establishing around 12,000 years ago. Sand and bulk density profiles reveal significant periods …


What Is Co2 Sequestration?, University Of North Dakota. Energy And Environmental Research Center Apr 2005

What Is Co2 Sequestration?, University Of North Dakota. Energy And Environmental Research Center

EERC Brochures and Fact Sheets

Fact sheet about the CO2 sequestration and the Plains CO2 Reduction (PCOR) Partnership. Defines CO2 sequestration and lists project partners. [This item is an outdated or superseded version and retained for historical purposes only. It may no longer reflect current information, policies, or practices.]


Seasonal Variability In Trace Metal Speciation And Vertical Redox Stratification Of Freshwater Lake And Marsh Sediments In The Kalamzoo River Watershed (Mi, Usa), Noah Tumusiime Ndenga Apr 2005

Seasonal Variability In Trace Metal Speciation And Vertical Redox Stratification Of Freshwater Lake And Marsh Sediments In The Kalamzoo River Watershed (Mi, Usa), Noah Tumusiime Ndenga

Masters Theses

This research was aimed at: 1) quantifying redox-sensitive parameters in order to study redox stratification of the upper freshwater sediments at Asylum Lake and Kleinstuck Marsh, 2) quantifying the speciation of metals (e.g., Pb, Mn, Fe, Cr, Cu, Zn, Co and Cd), particularly with respect to their association with Fe and Mn (hydr)oxide phases, and 3) assessing changes in redox stratification and metal speciation as a function of season in the sediments. Both the solid phase and sediment pore waters were collected to a depth of ~50cm. Pore waters were analyzed for redox-sensitive species and the sediment solid phase was …


The Effects Of Nutrient Concentrations On Macroinvertebrate Distributions In Georgia, Paula Michele Pollock Brossett Apr 2005

The Effects Of Nutrient Concentrations On Macroinvertebrate Distributions In Georgia, Paula Michele Pollock Brossett

Theses and Dissertations

Nutrients are considered the second largest nonpoint source pollutant in Georgia's running water ecosystems. Nutrients can naturally occur in low amounts and are typically increased in streams as a result of industry, agriculture, silviculture, and urbanization. In large amounts, nutrients can cause many problems to occur in the stream ecosystem. Macroinvertebrates have been established as good indicators for determining the level of impairment of a stream; however, not much research has been done on how nutrients affect macroinvertebrates in a stream. Approximately 225 reference and impaired streams were sampled over a 3 - year field season, (index period from September …


Producing Pulses In The Southern Agricultural Region, Peter White, Mark Seymour, Pam Burgess, Martin Harries Apr 2005

Producing Pulses In The Southern Agricultural Region, Peter White, Mark Seymour, Pam Burgess, Martin Harries

Bulletins 4000 -

The development of pulses in Western Australia has undergone tremendous advances over the past 12 years. From a tiny industry in the early 1990’s where the knowledge of both scientists and farmers was very limited, we now have a robust industry with production packages and improved varieties for all the grain legumes species that are well suited to our environment.

This book, which is both comprehensive and practical, collates much of the information gathered through pulse research and commercial experience over the past 10 years and will be valuable to all pulse growers, agronomists, students and industry advisors alike. The …


Use Of Tracers And Isotopes To Evaluate Vulnerability Of Water In Domestic Wells To Septic Waste, Ingrid M. Verstraeten, Gregory S. Fetterman, Michael T. Meyer, Thomas D. Bullen, Sonja Sebree Apr 2005

Use Of Tracers And Isotopes To Evaluate Vulnerability Of Water In Domestic Wells To Septic Waste, Ingrid M. Verstraeten, Gregory S. Fetterman, Michael T. Meyer, Thomas D. Bullen, Sonja Sebree

United States Geological Survey: Staff Publications

In Nebraska, a large number (>200) of shallow sand-point and cased wells completed in coarse alluvial sediments along rivers and lakes still are used to obtain drinking water for human consumption, even though construction of sand-point wells for consumptive uses has been banned since 1987. The quality of water from shallow domestic wells potentially vulnerable to seepage from septic systems was evaluated by analyzing for the presence of tracers and multiple isotopes. Samples were collected from 26 sand-point and perforated, cased domestic wells and were analyzed for bacteria, coliphages, nitrogen species, nitrogen and boron isotopes, dissolved organic carbon (DOC), …


An Investigation Of The Interlobate Area West Of Three Rivers, Michigan And Its Relationship To The Late Wisconsinan Glaciation Of Southwest Michigan, Scott J. Kendzierski Apr 2005

An Investigation Of The Interlobate Area West Of Three Rivers, Michigan And Its Relationship To The Late Wisconsinan Glaciation Of Southwest Michigan, Scott J. Kendzierski

Masters Theses

A detailed investigation of selected mineralogical and textural characteristics of glacial deposits was conducted in order to explore the complex relationships between the Lake Michigan and Saginaw Lobe ice-margins and associated depositional regimes during the deglaciation of southwest Michigan. Various analytical methodologies were applied to the characterization of glacial materials, glacial and post-glacial environments in order to infer a chronology of lobate activity.

The Sturgis Moraine, located in St. Joseph County, Michigan, is a major recessional moraine owing to the processes of both the Lake Michigan and Saginaw Lobes. Analysis of geologic materials and examination of subsurface data along with …


Glacial Stratigraphy And Surficial Geology Of The Decatur, Lawrence, And Paw Paw U.S.G.S.7.5 Minute Quadrangles In Van Buren County, Michigan, Brian Bird Apr 2005

Glacial Stratigraphy And Surficial Geology Of The Decatur, Lawrence, And Paw Paw U.S.G.S.7.5 Minute Quadrangles In Van Buren County, Michigan, Brian Bird

Masters Theses

The modern day landscape of Van Buren County Michigan was created by the advance and retreat of glaciers from about 13,000 to 20,000 years ago. The Lake Michigan Lobe of the Laurentide Ice Sheet sculpted southwest Michigan most recently. The sediments deposited by the glacier include diamicton, outwash sediments, and lacustrine deposits. The build up of sediment by the glaciers led to the construction of particular features such as moraines, till plains, and outwash fans. The huge amount of meltwater from the glaciers led to the erosion of channels throughout the area. In the area of this investigation the Ganges …


Sulfide Mineralization In Deep-Water Marine Sediments Related To Methane Transport, Methane Consumption, And Methane Gas Hydrates, Matthew K. Thompson, Walter S. Borowski, Charles K. Paull, William Ussler Iii Apr 2005

Sulfide Mineralization In Deep-Water Marine Sediments Related To Methane Transport, Methane Consumption, And Methane Gas Hydrates, Matthew K. Thompson, Walter S. Borowski, Charles K. Paull, William Ussler Iii

EKU Faculty and Staff Scholarship

Patterns of sulfide sulfur concentration and sulfur isotopic composition (d34 S) are perhaps related to upward methane transport, especially in sediments underlain by methane gas hydrate deposits. Increased methane delivery augments the effect of anaerobic methane oxidation (AMO) occurring at the sulfate-methane interface (SMI). Sulfate and methane co-consumption results in production of dissolved sulfide at the interface that is eventually sequestered within sulfide minerals (elemental sulfur, iron monosulfide, pyrite).

We examine the sediments of two piston cores collected over the Blake Ridge gas hydrate deposits (offshore southeastern United States) by extracting total sedimentary sulfide using chromium reduction. We use …


Correlation And Causes Of Fifth Order Cycles Within The Upper Cretaceous Eagle Formation, Bighorn Basin Of Wyoming, Kimberly Ann Johnson Apr 2005

Correlation And Causes Of Fifth Order Cycles Within The Upper Cretaceous Eagle Formation, Bighorn Basin Of Wyoming, Kimberly Ann Johnson

OES Theses and Dissertations

Cyclic stratification was examined in the Upper Cretaceous (Santonian-Campanian) section (Eagle Formation) within the Bighorn Basin of Wyoming. Of particular concern was the 103 to 104 year band, which in marine settings has been attributed to orbital forcing (Milankovitch cyclicity). A series of 19 sections were measured through the Virgelle Member of the Eagle Formation. Most were measured on the “J”-shaped escarpment that constitutes the nose and north flank of the Thermopolis anticline. Several others were measured at sites up to 30 km to the northwest along paleo-shoreline. In the study, detailed thickness data of all sections and …


Geology Of The Tierras Blancas Area In The Southeastern Acambay Graben, Central Mexico, Lonnie T. Mercer Mar 2005

Geology Of The Tierras Blancas Area In The Southeastern Acambay Graben, Central Mexico, Lonnie T. Mercer

Theses and Dissertations

Pliocene-Pleistocene sediments in the southeastern Acambay graben, central Mexico have yielded mammal fossils, including Equus simplicidens, cf. Rhynchotherium, ?Camelops, Mammuthus sp., Bison sp., and Antilocapra sp. The fossiliferous sediments include a period of lacustrine sedimentation in the late Pliocene-early Pleistocene that interrupted fluvial and alluvial sedimentation during the early Pliocene and Pleistocene. The sediments deposited in this late Pliocene paleolake record a history of lake level fluctuations, shown by lithologic variations in lacustrine sediments and abundance of vertebrate burrows. Volcanic and tectonic events in the Acambay graben were the major controls on sedimentation during Pliocene-Pleistocene time. …


The Benthic Community Of The Eastern Us Continental Shelf: A Literature Synopsis Of Benthic Faunal Resources, R. Allen Brooks, Carla N. Purdy, Susan S. Bell, Kenneth J. Sulak Mar 2005

The Benthic Community Of The Eastern Us Continental Shelf: A Literature Synopsis Of Benthic Faunal Resources, R. Allen Brooks, Carla N. Purdy, Susan S. Bell, Kenneth J. Sulak

United States Geological Survey: Staff Publications

The existing scientific literature on offshore benthic assemblages (OBA) residing along the US East and Gulf of Mexico continental shelf was reviewed. Identification was made of any associations between the dominant OBA and particular sediment types and/or bathymetry. Of special interest was the evaluation of reported effects of sand dredge/mining activities on the dominant OBA and recognition of data deficiencies. One hundred and twenty-two references were selected and classified as to type of study with pertinent results extracted. Polychaetes were predominantly cited as the principal infaunal taxa present in studies from both the Gulf of Mexico and US Atlantic coast. …


Sequence Stratigraphy Of The Bridal Veil Falls Limestone, Carboniferous, Lower Oquirrh Group, On Cascade Mountain, Utah: A Standard Morrowan Cyclostratigraphy For The Oquirrh Basin, David Joseph Shoore Mar 2005

Sequence Stratigraphy Of The Bridal Veil Falls Limestone, Carboniferous, Lower Oquirrh Group, On Cascade Mountain, Utah: A Standard Morrowan Cyclostratigraphy For The Oquirrh Basin, David Joseph Shoore

Theses and Dissertations

The Bridal Veil Falls Limestone (lowest 400 meters of the Permo-Carboniferous Oquirrh Group) is well exposed on the flanks of Cascade Mountain (Wasatch Front and adjacent mountain ranges) near Provo, Utah. Because of its excellent exposure and location in the heart of the Oquirrh depocenter, this area was selected to develop a sequence stratigraphic framework for Morrowan rocks that may be applied throughout the Oquirrh basin (NW Utah and southern Idaho) as well as the adjacent Ely and Bird Springs troughs. Eleven partial to complete sections of the Bridal Veil Falls Limestone were measured along the west and north flanks …


The Effects Of Fault-Induced Stress Anisotropy On Fracturing, Folding And Sill Emplacement: Insights From The Bowie Coal Mines, Southern Piceance Basin, Western Colorado., Eric Dean Robeck Mar 2005

The Effects Of Fault-Induced Stress Anisotropy On Fracturing, Folding And Sill Emplacement: Insights From The Bowie Coal Mines, Southern Piceance Basin, Western Colorado., Eric Dean Robeck

Theses and Dissertations

The recognition of fault-perturbed stress fields is an important tool in areas of mineral or hydrocarbon exploration. The Bowie underground coal mines of western Colorado expose a reverse-reactivated growth fault that perturbed the stress field during cleat (fracture) formation, rotating cleat orientations up to 500 m on both sides of the fault. Two unusual fracture types are found only in coal adjacent to the fault: (1) concentric cleats, highly curved fractures that form blocks resembling balls or eggs and (2) horsetail cleats, striated surfaces that superficially resemble shattercones and result from shear failure in coal. Numerical models created with the …