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  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
121

Clastic wedge development and sediment budget in a source-to-sink transect (Late Campanian western interior basin, SW Wyoming and N Colorado)

Gomez, Carolina Andrea 03 June 2010 (has links)
The problem of how sand and mud was distributed downslope, within linked alluvial-brackish water-marine shoreline systems of an extensive clastic wedge is addressed here. The Iles Clastic wedge accumulated over a time period of a few million years (my), and its component high-frequency regressive-transgressive sequences have a duration of a few 100 thousand years (ky). The sediment partitioning study provides insight into where the thickest sandstones and mudstones were located, and generates a model that can be applied to improving the management of hydrocarbons or water resources. A 300 km 2-D study transect across the Iles Clastic Wedge in SW Wyoming and N Colorado included subsurface well log information and outcrop stratigraphic columns. This information was used to correlate high-frequency sequences across several hundred kilometers, characterize depositional processes from proximal to distal reaches, develop a sediment partitioning model, and understand the role of the likely drivers in the development of the wedge and its internal sequences. The main results of this study are: (1) The Iles Clastic Wedge spans 3 my (500 m thick) and is composed internally of 11 sequences of 200-400 ky, each of which have significant regressive-transgressive transits of up to 90 km. Sediment partitioning analysis shows that within the regressive limb of the large wedge, the component regressive compartments tend to thicken basinwards, whereas transgressive compartments thicken landwards. This geometry is driven by preferential erosion in proximal areas during regression, bypassing much sediment to the marine shorelines, and transgressive backfilling into proximal areas previously eroded more deeply. (2) The greatest concentration of sands tends to be located in the proximal fluvial and estuarine facies of the transgressive compartments and within the medial shoreline/deltaic facies of the regressive compartments. (3) As the high-frequency sequences developed, the effectiveness of basinward sand partitioning reaches a maximum value near the peak regression level of the wedge, reflecting stronger erosion and sediment bypass during this times. (4) The development of the Iles Clastic Wedge was influenced by both tectonic and eustatic drivers, with important tectonic control in the upstream reaches. On a 4th-order timescale, the Iles Wedge internal sequences were likely influenced mainly by eustasy. / text
122

Sedimentology and Stratigraphy of the Middle Jurassic Preuss Sandstonein Northern Utah and Eastern Idaho

Cook, Preston Scott 01 June 2016 (has links)
The purpose of this study is to analyze the sedimentology and stratigraphy of the Middle Jurassic Preuss Sandstone and re-evaluate past sedimentological interpretations. The Preuss is located in northern Utah, western Wyoming and eastern Idaho and is stratigraphically equivalent to the Entrada Sandstone, which is Callovian in age (Dossett et al., 2014). This study is the first attempt at 1) a sequence stratigraphic framework, 2) a petroleum system analysis and 3) an extraterrestrial analog study for the Preuss. This study frames the Preuss within three broad facies groups: marine, coastal and terrestrial. The marine group includes the open marine and restricted marine facies with associated subfacies, the coastal group includes coastal sabkha and associated subfacies, and the terrestrial group includes alluvial, inland sabkha and eolian facies with associated subfacies. Three sections in northern Utah and one section in eastern Idaho compromise the focus of this study. The three Utah sections were measured and described, and samples were collected from two Utah sections and the Idaho section. The Preuss Sandstone was deposited in an asymmetrical retroarc basin, consequently the Preuss thickens from the east towards west-central Utah and the Jurassic Elko highlands. The deposits are mostly terrestrial, which is in accord with recent sedimentological interpretations, but at odds with the old paradigm, which postulates that the Entrada and Preuss were largely tidal in origin. There are marine transgressions within the trough of the retroarc basin, and the transgressions affect terrestrial sedimentary patterns. During marine incurstions, alluvium shed off the highlands is confined west of the seaway, and does not prograde east of the trough until all the available accommodation is filled. The Preuss was deposited during a complete third-order sequence-stratigraphic cycle that lies within the Lower Zuni II second-order lowstand. The Preuss Sandstone can be used as an outcrop analog for ancient and modern environments both here on Earth and on other planetary bodies. The petroliferous Norphlet Formation along the U.S. Gulf Coast was deposited in an environment very similar to the Preuss, but the Waltherian succession of facies might be slightly different. Likewise, the facies present in the Preuss are analogous to modern arid environments, such as the Persian Gulf. Furthermore, the alluvial, sabkha, eolian and shallow marine facies of the Preuss are highly similar to facies observed in ancient Martian environments and modern environments on Saturn's moon, Titan.
123

Paleo-Environmental Interpretations and Weathering Effects of the Mowry Shale from Geochemical Analysis of Outcrop Samples in the Western Margin of the Wind River Basin near Lander, Wyoming

Tuttle, Trevor Robinson 01 March 2018 (has links)
The Cretaceous Mowry Shale is an organic-rich, siliceous marine shale, and as such is a known source rock in the Western United States. Studies have documented that total organic carbon (TOC) in the Wind River Basin, Wyoming increases to the southeast. These studies cover large areas with limited sample sets. In this study, over 250 samples were collected near Lander, Wyoming to address spatial heterogeneity of TOC within the Mowry Shale at a much finer scale than previously examined. Samples were collected along five vertical sections at three localities, and following correlation of the vertical sections, which was strongly aided by the presence of regional bentonite horizons, samples were collected laterally from the same unit at regular 25-foot intervals. These samples were analyzed using pyrolysis and x-ray diffraction techniques. Average TOC values are fairly consistent within the study area (1.65%, with a range of 2.10% to 1.15%). Average Tmax values for vertical and lateral samples is 433 °C with a standard deviation of 7.25 °C suggesting immature to very early oil window thermal maturity. Kerogen types are determined to be dominantly type III, suggesting a dominance of terrestrial input, becoming slightly more mixed type II/III to the southeast. Redox-sensitive trace metals such as uranium, thorium, vanadium, chromium, cobalt, and molybdenum values all suggest a slightly oxygenated sediment water interface during time of deposition. These pyrolysis and trace metal data suggest that the study area was in a prograding proximal marine/prodeltaic depositional environment during Upper Mowry time with influences from higher energy bottom flows. Lateral homogeneity of strata and the low variability in geochemical character across the study area suggest that the local basin in the study area was not segmented by structural or oceanographic conditions. While efforts were made to collect unaltered outcrop samples (digging back into what appeared to be unfractured, unaltered rock), alteration or weathering of organic material is a concern for source rock evaluation of near-surface outcrops. In order to address this concern, a 5-foot-deep trench was dug back into the outcrop at the target horizon in one locality. Samples were taken at regular three-inch intervals from this trench as it was excavated to determine the effect of weathering on TOC in the study area. Based on pyrolysis results, TOC was affected by weathering only along fracture sets (several samples intersected fractures in the shallow subsurface) and did not appreciably increase from the surface to a depth of five feet. Due to the impermeable nature of shale rock, decreases of TOC due to weathering appear to be limited to the immediate surface of samples and along fracture sets.
124

Anti-Chinese violence in the American northwest : from community politics to international diplomacy, 1885-1888

Dettmann, Jeffrey Alan, 1967- 20 April 2011 (has links)
Not available / text
125

Novel Techniques to Improve Restoration of Native Rangeland Species

Anderson, Rhett Michael 27 March 2020 (has links)
The sagebrush steppe is a particularly sensitive ecosystem that is easily disturbed by fires, oil and gas extraction, woody-plant encroachment, and overgrazing. The natural regeneration of native species following a disturbance within this system is typically slow and sporadic, which allows invasive grasses to occupy the landscape. Attempts to assist the recovery of these landscapes through direct seeding is commonly met with poor success rates, particularly in lower elevation, drier sites. Novel seed enhancement technologies and planting techniques that mitigate limiting factors impairing restoration efforts may improve the likelihood of restoring these degraded areas. For chapter 1, we evaluated a solid-matrix priming technique, where bluebunch wheatgrass (Pseudoroegneria spicata) and Lewis flax (Linum lewisii) were primed and then the priming matrix and seed were pelleted together. We evaluated primed seed that had been incorporated into pellets at two field sites against seed that was pelleted but been left unprimed, and untreated seed (control). These three seed treatments were planted in the spring (mid-march) in shallow (2-cm) and deep (15-cm) furrows, in a complete factorial design. We found that primed seeds generally produced higher plant densities than control seed at the beginning of the growing season; however, its influence diminished towards the end of the growing season. We also found that deep furrows increased plant density throughout the growing season and even into the following year. The combination of priming and deep furrows outperformed control seed in shallow furrows in all measured metrics. For chapter 2, we evaluated a seed conglomeration technique for improving Wyoming big sagebrush (Artemisia tridentata ssp. Wyomingensis) emergence and survival under fall and winter plantings. The trial was implemented at five sites across Utah and Nevada in a randomized complete block-split-split plot design, with site, and planting season, comprising the split-plot factors. Each site and season combination was seeded with conglomerated and control seed. We found that in most cases, a fall seeding of Wyoming big sagebrush was either the same or more successful compared to planting on the snow in the winter, which is the current suggested practice. Our results also demonstrated that seed conglomeration produced higher plant densities compared to control seed throughout the growing season. The higher density of plants produced from conglomerates combined with the improved seed delivery provided by the conglomeration technique was estimated to offset the cost in producing conglomerates and reduce overall restoration costs by 41%.
126

Flexural Partitioning of the Later Albian-Cenomanian Cordilleran Foreland-basin System, Utah, Wyoming, and Colorado

Wink, Jared Timothy 10 May 2022 (has links)
No description available.
127

Growth, Morphology, Habit and Habitat of Selected Brachiopod and Mollusc Species from the Meade Peak Member of the Phosphoria Formation, Permian, Northeastern Utah - Southeastern Idaho - Southwestern Wyoming

Russell, Scott Lewis 01 May 1980 (has links)
The Permian Meade Peak Member of the Phosphoria Formation was examined at four localities in this investigation. Fossils were collected at each locality. The four collecting localities visited in this investigation are: Brazier Canyon, Utah, Montpelier Canyon, Idaho, Coal Canyon, Wyoming, and Cokeville, Wyoming. The environment of deposition of the Meade Peak Member in the study area is inferred to have been an outer shelf or basin characterized by moderately deep and quiet water. This has aided reconstruction of life habits, population dynamics, and growth characteristics of the examined species. The articulate brachiopod Leiorhynchoidea weeksi is inferred to have attached itself to the substrate by means of a pedicle. The observed variability in the sulcus of this species is assumed to have been influenced by intraspecific competition, which may reflect partitioning of nutrient resources at different levels in the water above the substrate. The articulate brachiopod Lissochonetes ostiolatus probably assumed an unattached existence, lying free on the substrate. Several population samples exhibited stunted growth relative to the L. ostiolatus population sample from Montpelier Canyon. Two environmental variants possibly contributed to the inhibition of growth. These are negative Eh, inferred from the associated organic matter in the lithologies, and competition for space. Lingula carbonaria an inarticulate brachiopod, is thought to have had an infaunal mode of life. A population sample of L. carbonaria from Cokeville exhibits substantially larger morphologic mean sizes than two other population samples. These differences can be explained by the fact the sandy lithology from which the larger collection was taken was associated with conditions which facilitated growth. Also, availability of phosphate, inferred from the P2O5 content of the lithology, probably accelerated growth because inarticulates utilize calcium phosphate as shell material. Orbiculoidea missouriensis is an inarticulate brachiopod. It is inferred to have been attached to the substrate by a pedicle. OF the three population samples of O. missouriensis analyzed, the sample from Brazier Canyon displays larger morphologic mean sizes. This is interpreted as indicating that reducing conditions, inferred from associated organic matter, were milder in that environment. The gastropod bablyonites ferrieri displaysa a low, expanded from, and is thought to have crawled over the surface of the sediment. The food source of this gastropod is not known, but may have been algae, carrion, detritus, or soft-bodied invertebrates. Two bivalves collected are assumed to have been shallow burrowing, labial palp feeders. Both Nuculopsis montpelierensis and polidevcia obesa represent this mode of life. Of the two population samples of P. obesa examined, the one from Cokeville displays larger morphologic means. The environmental stimuli proposed for this difference is competition and an inferred softer substrate in the montpelier assemblage. The bivalve Edmondia phosphatica is inferred to have been a shallow burrowing, siphonate species. Streblochondria montpelierensis and Aviculopecten phosphaticus are bivalves related to modern pectenoids. S. montpelierensis is assumed to have been a byssally attached epifaunal bivalve. The environmental factors influencing the morphologic variation are also inferred to have affected size-frequency distributions and survivorship curves. The effects of reducing conditions have resulted in higher juvenille mortality and/or inhibited growth. Coarser substrates have yielded population samples that exhibit negatively skewed distributions, whereas finer-grained substrates have yielded positively skewed distributions. Growth curves constructed for each population sample generally show a decline in growth rate with age. Some linear trends are noted. Growth lines were used to infer an approximate life span for each species. Conservative approximations of the life spans of the examined species are: L. weeksi, 9 years; L. ostiolatus, 5 years; L. carbonaria, 8 years; A. phosphaticus, 4 years; O. missouriensis, 2.3 years; P. obesa, 5 years; and B. ferrieri, 3.4 years.
128

Landscape management for a landscape species: Understanding the impacts of anthropogenic factors on sage-grouse populations in Wyoming

Spence, Emma Suzuki 28 April 2017 (has links)
No description available.
129

SEDIMENTOLOGY AND ICHNOLOGY OF LATE CAMBRIAN TO EARLY ORDOVICIAN SKOLITHOS SANDSTONE IN THE DEADWOOD FORMATION, NORTHERN BLACK HILLS, SOUTH DAKOTA, AND SOUTHEASTERN BEAR LODGE MOUNTAINS, WYOMING

Sokoloski, William P. 09 June 2005 (has links)
No description available.
130

Intercorrelation Patterns Relating to Career Aspiration Among southern Appalachian Youth

Suddarth, Jeane R. 24 May 2010 (has links)
The objectives of this study were to devise testing procedures for identification of contributing factors in career development problems believed to be prevalent in southern Appalachia and in particular, Wyoming County, West Virginia; to identify career development problems unique to students in this region; and to define and analyze interrelating factors. It was hoped that this study could add to a body of research which might be utilized to understand the unique southern Appalachian student and his career development needs. / Ed. D.

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