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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.
1

Geology of the Southwestern Part of the Randolph Quadrangle, Utah-Wyoming

Hansen, Steven C. 01 May 1964 (has links)
General Statement A detailed study of the southwestern part of the Randolph quadrangle was undertaken in view of the fact that Richardson (1941) mapped a large area of undifferentiated Ordovician rock. Therefore, the purposes of this investigation are: (1) to prepare a more detailed geologic map of the south­western part of the Randolph quadrangle (Plate 1), (2) to describe the struc­ture, stratigraphy, and geologic history of the area, and (3) to relate the geology to adjacent areas. The elevation of the area mapped ranges from approximately 8, 910 to 6, 700 feet above sea level with the major part of the area above 8, 000 feet. This area forms part of the eastern ridge of the Bear River Range (Williams, 1948, p. 1, 125-1, 126). The southern boundary of the area extends east from the southwest corner of the Randolph quadrangle for a distance of about 4 miles. The eastern boundary extends northward about 11 miles and is parallel to the mountain front. The northern boundary is less well defined and is taken as the ridge separating Curtis Creek from the next canyon to the north. The western boundary extends south approximately 10 miles to the southwest corner of the Randolph quadrangle. The southwestern part of the Randolph quadrangle (Figure 1) covers approximately 56 square miles and lies approximately 60 per cent in Cache County and 40 per cent in Rich County. The major part of the area lies within the Cache National Forest. The area mapped is generally accessible from mid-June to mid- September. A road is maintained along the length of the area by the U. S. Forest Service and is passable by automobile except during heavy rain- storms in the summer months. Field Work The field work was done during the summer of 1963. Formation con- tacts, attitudes, and faults were mapped in the field on aerial photographs of the approximate scale 1:20, 000. This information, concerning the south- western part of the Randolph quadrangle, was transferred to a base map constructed from the topographic map of the U. S. Geological Survey of the same area (1912 edition). The base map was enlarged to the scale 1:24, 000. Stratigraphic sections were measured with a 50-foot steel tape. A Brunton compass was used to measure attitudes and slope angles. Sample rock types were collected from each unit and compared with the rock-color chart (Goddard, 1951) to obtain standard color names. Fossils were collected and identified in the laboratory by the author. Previous Investigations The earlier geologic reports from the general area of the Randolph quadrangle are found in the Hayden Survey and the survey of the Fortieth Parallel supervised by King. Hayden (1871, p. 150-156), Peale (1877, p. 573-609), Hague (1877, p. 393-442), and Emmons (1877, p. 326-393) all commented upon the general area. Walcott (1908) studied the Cambrian rocks of the Bear River Range and defined eight formations. Veatch (1907) studied the area adjacent to the Randolph quadrangle in Wyoming. In the Randolph quadrangle, Richardson (1913) divided the Ordovician rocks into three formations, identified the Silurian rocks as a formation, defined one Mississippian formation, and later (1941) published a geologic map of the quadrangle. Mansfield's (1927) study of southeastern Idaho provided valu­able information concerning regional structure and stratigraphy. Williams (1948) mapped the Logan quadrangle which is adjacent to the area on the west. Specific studies (Ross, 1949, 1951; Maxey, 1941, 1958) have given more detailed information concerning Cambrian and Ordovician rocks of the area. A recent publication by Armstrong and Cressman (1963) is important in dating the uplift and thrust faulting in the ancestral Bear River Range. The Geologic Map of Utah (Stokes, 1961) followed the interpretaion of Richardson (1941), for the southwestern part of the Randolph quadrangle, except in the designation of the Wasatch formation which is shown as Knight conglomerate.
2

LATE QUATERNARY CRUSTAL DEFORMATION AT THE APEX OF THE MOUNT MCKINLEY RESTRAINING BEND OF THE DENALI FAULT, ALASKA

Burkett, Corey A 01 January 2014 (has links)
The tallest mountain in North America, Mount McKinley is situated inside a sharp bend in the right‐lateral Denali fault. This anomalous topography is clearly associated with the complex geometry of the Denali fault, but how this topography evolves in conjunction with the adjacent strike‐slip fault is unknown. To constrain how this fault bend is deforming, the Quaternary fault‐related deformation on the opposite side of the Denali fault from Mount McKinley were documented through combined geologic mapping, active fault characterization, and analysis of background seismicity. My mapping illustrates an east‐west change in faulting style where normal faults occur east of the fault bend and thrust faults predominate to the west. These faults offset glacial outwash terraces and moraines which, with tentative correlations with the regional glacial history, provide fault slip rates that suggest that the Denali fault bend is migrating southwestward. The complex and elevated regional seismicity corroborates the style of faulting associated with the fault bend and provide additional subsurface control on the location of active faults. Seismologic and neotectonic constraints suggest that the maximum compressive stress axis rotates from vertical east of the bend to horizontal and Denali fault‐normal west of the bend.
3

Surficial Deposits and Geologic History, Northern Bear Lake Valley, Idaho

Robertson, George C., III 01 May 1978 (has links)
Detailed geologic mapping and subsurface study of late Pleistocene and Holocene sediments in northern Bear Lake Valley show at least four episodes of deposition of fluvial, marsh, bay, and lacustrine sediments. from oldest to youngest, these are the Ovid, Liberty, Wardboro, and Lifton episodes. These episodes are substantially different than those proposed by previous investigators. The informal term Bear Lake Formation is formally redefined here as the Bear Lake Group, and includes the newly defined Ovid Formation, Liberty Formation, lanark Formation, and Rainb= Gravel. The overlying Wardboro Loess, also defined here, provides a probably age of 11,000 to 8,000 years B. P. for widespread post-Wisconsinan deposition of loess in northern Utah and southern Idaho. The Ovid Episode began prior to 27,400 years B. P ., d=ing a warm, dry, climatic interval. Sediments deposited during the early part of the Ovid Episode include marsh and bay deposits of the l=er part of the Ovid Formation in northern Bear Lake Valley , probably similar deposits of the lCN~er part of the lanark Formation west of the Bloomington Scarp (on the west side of Bear Lake Valley), and marshy deposits beneath Bear Lake in southern Bear Lake Valley. West-sloping pediments at the north end of Bear Lake Valley, between Bennington and Georgetown, Idaho, and old alluvial fans, also may have formed at this time. The northern outlet of the valley was near 5990 feet at this time . Downfaulting along the Bear L3ke fault zone on the east side of Bear L3ke Valley, and prol:able eastward tilting affected the central valley during the Ovid Episode. At this time, deposition of deep-water carbonates, beneath Bear L3ke, prol:ably began in southern Bear L3ke Valley. Later, cooler- and Jl'Oister clirratic conditions of a Late Pleistocene glacial interval (Pinedale?) resulted in a shall& extension of this lake into northern Bear L3ke Valley during the Liberty Episode. Progradational, shallow-water sand deposits of the Liberty Formation show that Bear Lake attained its most recent maximum areal extent at this time. Simultaneous deposition of the Rainbow Gravel at the entrance of the Bear River into the valley, near Dingle, Idaho, and of the sandy, deltaic upper part of the Lanark Formation along the west side of the valley, reflected the increased addition of sediments, probably due to glaciation and higher stream discharges. The valley outlet was at an altitude near 5945 feet. Downcutting of the valley outlet and waning moist climatic conditions led to exposure of lake beds, increased effectiveness of the wind, and deposition of the Wardboro Loess during the Wardboro Episode. This loess prol:ably is correlative with the Niter Loess in Thatcher Basin (Gem and Gentile valleys, Idaho). It is slightly more than 8,000 C14 years old, and probably less than 11,000 year old. Recurrent faulting along the east margin (Bear Lake fault zone) and west margin (Bloomington Scarp) of the valley at the onset of the Lifton Episode led to a brief re- expansion of Bear Lake, and then a recession southward to its present position near 5923 feet. During this time, a series of beach ridges, successively younger southward, and undifferentiated sediments of marsh, bay, and stream origin, formed in northern Bear Lake Valley. The present valley outlet is near 5873 feet.
4

Surficial Geology of the Smithfield Quadrangle Cache County, Utah

Lowe, Michael V. 01 May 1987 (has links)
The Smithfield 7.5' quadrangle is located about 13.8 kilometers (8.6 miles) south of the Utah-Idaho State Line and occupies the central portion of the eastern side of Cache Valley, Utah. The mapped area contains more than 55 square miles. The Bear River Range on the eastern side of the quadrangle contains stratigraphic units ranging from Precambrian to Quaternary age. Cache Valley contains deposits of Tertiary and Quaternary age. Quaternary units in the Smithfield quadrangle are subdivided into thirty-two map units based on age and genesis. Five ages of Quaternary units are identified, and these units are assigned to one of fourteen genetic types. The East Cache fault zone is mapped along the western edge of the Bear River Range. Early Quaternary time was principally a period of pediment formation, followed by normal faulting, erosion, and alluvial-fan deposition. Cache Valley was later occupied by a pre-Bonneville cycle lake which is tentatively correlated with the Little Valley lake cycle. This lacustrine cycle was followed by more erosion and alluvial-fan deposition. The current Cache Valley landscape is dominated by the sediments and geomorphic features of Pleistocene Lake Bonneville. Alluvial-fan deposition has been the principal geologic process in post-Lake Bonneville time. Geologic hazards in the Smithfield quadrangle include flooding, landslides, debris flows, rock fall, problem soils, shallow ground water, earthquake ground shaking, surface fault rupture, and liquefaction. Some of the areas affected by these hazards and measures for mitigating the hazards are identified. Bonneville lake cycle fine-grained offshore deposits and the Tertiary Salt Lake Formation are the primary geologic units susceptible to landsliding.
5

Geomorphic and Hydrologic Information from High Altitude Aerial Photography

Bruce, William David 09 1900 (has links)
High altitude photography represents a new, potentially valuable, but largely untested information source for the interpretation of surficial deposits. It differs significantly in sensitivity and perspective from conventional aerial photography. It posesses different values and limitations which must be evaluated in their own right. The photography examined is shown to provide an excellent and reliable record of stream pattern geometry, and of stream flow regularity characteristics which are related to deposit slope form and material characteristics. The important image density component of the photographic record must be corrected for distortion but shows a consistent relationship with characteristics of near surface deposit hydrology. Photography and imagery from high or orbital altitudes will soon be a widely if not universally available information source. It is evident that such information can make a valid and useful contribution in geomorphic studies. This information is complimentary to existing techniques of data collection, and likely to realize substantial savings in time and efficiency while permitting wider application of findings. / Thesis / Master of Science (MSc)
6

Regional Jointing Pattern Within the Surficial Glacial Sediments and Bedrock of South-Central Ontario

Daniel, Sheila Ellen 03 1900 (has links)
<p> There is mounting pressure to find suitable disposal sites for both household and industrial waste in south-central Ontario as a solution to Metropolitan Toronto's growing 'garbage crisis'. New data indicate that the fine-grained glacial sediments of south-central Ontario, previously considered to be 'tight' and impermeable, are in fact penetrated by an extensive joint system. This thesis provides basic information regarding the regional character, orientation and origin of joints within the surficial glacial sediments and bedrock of south-central Ontario. Three regional joint sets can be identified. Within the bedrock, the joint sets are oriented northeast/southwest, northwest/southeast and north/south. This trend is consistent with the regional jointing pattern within the overlying glacial sediments and suggests that the joints may have propagated from the bedrock into the glacial sediments. A comparison between the regional jointing pattern identified in bedrock and glacial materials and the orientation of stress release structures suggests that the regional pattern of jointing is controlled by the regional stress field which results from intraplate tectonic stresses. However, the orientation of joints at any individual site may also be controlled by 'local' factors such as face orientation, direction of glacial ice movement and lithology and by randomly oriented joints formed as the result of physical and chemical weathering, synaeresis, subglacial deformation and stress relief. The identification of regional jointing pattern within south-central Ontario allows the prediction of joint characteristics and orientations at potential landfill sites in the region, critical to the accurate evaluation of the permeability of the substrate materials.</p> / Thesis / Master of Science (MSc)
7

Prehistoric and modern debris flows in semi-arid watersheds: Implications for hazard assessments in a changing climate

Youberg, Ann M. January 2013 (has links)
In a series of three studies, we assess modern debris-flow hazards in Arizona from extreme precipitation events and following wildfires. In the first study, we use a combination of surficial geologic mapping, ¹⁰Be exposure age dating and modeling to assess prehistoric to modern debris-flow deposits on two alluvial fans in order to place debris-flow hazards in the context of both the modern environment and the last major period of climate change. Late Pleistocene to early Holocene debris flows were larger and likely initiated by larger landslides or other mass movement failures, unlike recent debris flows that typically initiate from shallow (~1 m) failures and scour channels, thus limiting total volumes. In the second study we assess the predictive strengths of existing post wildfire debris-flow probability and volume models for use in Arizona's varied physiographic regions, and define a new rainfall threshold valid for Arizona. We show that all of the models have adequate predictive strength throughout most of the state, and that the debris-flow volume model over-predicts in all of our study areas. Our analysis shows that the choice of a model for a hazard assessment depends strongly on location. The objectively defined rainfall intensity-duration thresholds of I₁₀ and I₁₅ (52 and 42 mm h⁻¹, respectively) have the strongest predictive strengths, although all five of the threshold models performed well. In the third study, we explore various basin physiographic and soil burn severity factors to identify patterns and criteria that can be used to discriminate between potential non-debris-flow (nD) and debris-flow (D) producing basins. Findings from this study show that a metric of percent basins area with high soil burn severity on slopes ≥30 degrees provides a stronger discrimination between nD and D basins than do basin metrics, such as mean basin gradient or relief. Mean basin elevation was also found to discriminate nD from D basins and is likely a proxy for forest type and density, which relates to soil thickness, root density and the magnitude of post-disturbance erosion. Finally, we found that post-fire channel heads formed at essentially the same slope range (~30-40 degrees) as saturation-induced hill slope failures.
8

Surficial Materials Mapping and Surface Lineaments Analysis in the Umiujalik Lake area, Nunavut, Using RADARSAT-2 Polarimetric SAR, LANDSAT-7, and DEM Images

Shelat, Yask 01 April 2012 (has links)
This thesis is focused on the utilization of RADARSAT-2 polarimetric SAR data for mapping two surficial aspects of the Umiujalik Lake area, Nunavut, Canada: i) materials, such as bedrock, boulders, organic material, sand and gravel, thick and thin till; and ii) lineaments. To achieve these tasks, RADARSAT-2 polarimetric SAR images with three west-looking, increasing incidence angles (FQ1, FQ12, and FQ20, respectively) were used alone and in combination with LANDSAT-7 ETM+ and Digital Elevation Model (DEM) image data. The surficial materials mapping study tested: i) the effects of incidence angles on mapping accuracy; and ii) non-polarimetric and polarimetric classifiers. For non-polarimetric analysis, a Maximum Likelihood Classification (MLC) algorithm was applied to different combinations of RADARSAT-2, LANDSAT-7 ETM+, and DEM images, achieving a maximum overall classification accuracy of 85%. Polarimetric analyses first included computation of polarimetric signatures to understand the scattering mechanisms of the considered surficial materials, i.e., surface, volume, and multiple scatterings. It also tested three polarimetric classifiers: supervised Wishart (overall accuracy of 48.7% from FQ12 image), and unsupervised Freeman-Wishart, and Wishart-H/ /A. Three main conclusions were reached: i) high incidence angle greatly decreases classification accuracy for the HH polarized image when used alone, but incidence angle has little effect when the HV polarization is added; ii) combining images with three incidence angles (FQ1, FQ12, and FQ20) gives higher accuracy with the maximum likelihood classifier; and iii) the medium incidence angle image (FQ12) produces the best classification accuracy using polarimetric classifiers. In the second part of the study, surface lineaments were mapped using RADARSAT-2 SAR single-polarized images, RGB HH, HV, VV composites, polarimetric total power images, and LANDSAT-7 ETM+ principal component images. Polarization effect analysis showed that regardless of beam mode, more lineaments were identified on the HH image than on the HV image, and the maximum number of lineaments was identified on the multi-polarized RGB composite. Incidence angle effects results showed that regardless of polarization modes, the FQ12 image yielded more lineaments than the FQ1 or FQ20 images. The majority of lineaments are oriented in NW and NNW directions, which correspond to the ice flow direction during the last glaciation.
9

CONTROL OF THE SURFICIAL FINE-GRAINED LAMINAE UPON STREAM CARBON AND NITROGEN CYCLES

Ford, William I, III 01 January 2014 (has links)
This dissertation investigated the impact of the Surficial Fine-Grained Laminae (SFGL) upon stream biogeochemical cycles to constrain stream C and N budgets. Collection and analysis of 8 years of transported sediment elemental and isotopic signatures, weekly, from a SFGL dominated stream, a novel dissolved C and N dataset, statistical and time-series analysis of sediment and dissolved data, and development of a comprehensive modeling framework that couples hydrodynamics, sediment, C and N biogeochemistry, and stable isotope sub-models to simulate fluvial C and N budgets was used. SFGL C modeling suggests benthic particulate C stocks and transport vary seasonally and annually but are in a state of long-term equilibrium which is governed by negative feedback mechanisms whereby high POC export due to extreme hydrologic events and high frequency hydrologic events reduces benthic particulate C stocks and inhibits benthic particulate C growth. Model distribution fitting suggests transported particulate C in SFGL streams is Gamma distributed; in which statistical moments are governed by variability of the SFGL. Stable isotope un-mixing of the bed source suggests that the SFGL has varying levels of carbon quality seasonally and annually, in which non-equilibrium conditions stem from extreme depositional events. Coupling stable isotope mass balance and SFGL fractionation processes into water quality modeling frameworks, reduced uncertainty of the C budget by nearly 60%, suggesting algal sloughing constitutes nearly 40% of the total organic C budget, shifting the balance from dissolved C to particulate C dominated. Time series analysis of the eight year dataset suggest nitrogen dynamics in the SFGL dominated stream were consistent with existing conceptual models when algal biomass is the prominent organic matter source in the SFGL, but contradicts conventional wisdom in winter through late spring when abiotic sorption appears prominent. The development of a new numerical model to simulate the fluvial N budget couples this new conceptual model of SFGL stream N dynamics to isotope mass-balances and C dynamics in order to provide a comprehensive management tool for restoration engineers. Meta-analysis and upscaling of results for regional to global scales will enable researchers to place the role of the SFGL in a broader context.
10

Κοκκομετρική μελέτη επιφανειακών ιζημάτων (0-50 cm) του Αμβρακικού κόλπου

Δήμας, Ξενοφών, Καλύβα, Μαρία 04 July 2013 (has links)
Στην παρούσα εργασία μελετήθηκαν η κοκκομετρία των επιφανειακών ιζημάτων του Αμβρακικού κόλπου. Τα ιζήματα που καθιζάνουν στον πυθμένα μιας θάλασσας καθώς και ο ρυθμός με τον οποίον αυτά αποτίθονται είναι εξαιρετικοί δείκτες του τρόπου λειτουργίας του υδάτινου αυτού σώματος. Επίσης μέσω των ιζημάτων γίνονται αντιληπτές οι σχέσεις αλληλοεξάρτησης του υδάτινου σώματος με τη στεριά και πως οι διεργασίες που λαμβάνουν χώρα στην στεριά επηρεάζουν τη ζωή στη θάλασσα. / The present study have examined the grain size of the surficial sediments of Amvrakikos gulf. The sediments that subside at the bottom of the sea and the speed of these deposits are excellent ways to find out the mechanisms and the way they faction. In addition, we can examine the correlation between sediments and water column. The processes that take place on land might affect the sea’s living life. The aim of the present study is to sustain laboratory results in order to establish the relationships between grain size of surfacial sediments in Amvrakikos gulf, using statistical parameters.

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