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Articles 961 - 990 of 2252
Full-Text Articles in Geomorphology
Orbital Periodicities Reflected In Ancient Surfaces Of Our Solar System And The Implications For A Record Of Early Life, Dixie Lee Androes
Orbital Periodicities Reflected In Ancient Surfaces Of Our Solar System And The Implications For A Record Of Early Life, Dixie Lee Androes
Graduate Theses and Dissertations
Uniformitarian processes, governed by invariant physical laws, remain the most reliable source for reconstructing the past. Driving many of the repetitive, predictable processes are the orbital dynamics of the Sun-Planet-Moon systems. Astronomical periodicities range from a few hours (tides) to thousands of years (Milankovitch). These periodicities, combined with geomorphic observations of planetary surfaces, constrain the time-dependent processes and allow for reconstruction of events and conditions favorable for sedimentary accumulations. This research suggests that seasonal sedimentary processes are dominant on Titan and Mars, and have played a significant role in the formation of ancient banded-iron formations (BIF's) on Earth.
Earth, Mars, …
Assessment Of The Oxbow Morphology Of The Caloosahatchee River And Its Evolution Over Time: A Case Study In South Florida, Chloe Delhomme
Assessment Of The Oxbow Morphology Of The Caloosahatchee River And Its Evolution Over Time: A Case Study In South Florida, Chloe Delhomme
USF Tampa Graduate Theses and Dissertations
The Caloosahatchee River, located in Southern Florida, was originally a meandering and relatively shallow river. During the 1920s, the Caloosahatchee River was channelized and became the C-43 canal. The channelization has significantly impacted the river ecosystem, particularly the oxbows. The oxbows are the U-shaped water bodies on each side of the river channel, which are the remnant bends of the original river. To understand how anthropogenic influence affects hydrologic systems, the proposed case study was designed to assess the geomorphic changes of the oxbows of the Caloosahatchee River, Florida. Understanding and documenting the evolution of river morphology is becoming increasingly …
Factors Influencing Landslides In The Bittercreek Wildlife Refuge, David Mceachern
Factors Influencing Landslides In The Bittercreek Wildlife Refuge, David Mceachern
Natural Resources Management and Environmental Sciences
No abstract provided.
4th International Union Of Soil Sciences Soil Classification Conference Field Tour Guidebook
4th International Union Of Soil Sciences Soil Classification Conference Field Tour Guidebook
Conservation and Survey Division: Faculty and Staff Publications
No abstract provided.
North Central Region Soil Survey Conference Field Tour
North Central Region Soil Survey Conference Field Tour
Conservation and Survey Division: Faculty and Staff Publications
No abstract provided.
Sedimentology And Geochronology Of Holocene Paleochannel Features In The Lower Ohio River Valley, Indiana, Kathryn G. De Rego, C. Russell Stafford, Mark Cantin
Sedimentology And Geochronology Of Holocene Paleochannel Features In The Lower Ohio River Valley, Indiana, Kathryn G. De Rego, C. Russell Stafford, Mark Cantin
Symposium 2012
Rivers condition human settlement strategy by determining both the location of aquatic resources and the stability of the landscape. Therefore, understanding where the river was and how quickly it migrated in the past aids in predicting buried site potential. This study investigates the sedimentology and geochronology of paleochannel deposits along the Lower Ohio River floodplain. A series of low, wide swales are prominent features in a series of bottoms in a ~40 km section of the river valley downstream from the Falls of the Ohio. Previous studies in Knob Creek Bottom indicate that one of these paleochannel swales was active …
Impacts Of Hard Stabilization On The Shore Of Yellowstone Lake, Yellowstone National Park, Wyoming, Usa, John Chandler Dennis
Impacts Of Hard Stabilization On The Shore Of Yellowstone Lake, Yellowstone National Park, Wyoming, Usa, John Chandler Dennis
Graduate Theses and Dissertations
Discussions related to the adverse impacts associated with shore armor (i.e. seawalls and riprap) are a common topic within the coastal community. While many agree that the installation of these structures alters the shores geomorphic response, there is disagreement in the type and degree of response. Furthermore, studies that have delved into this topic have been conducted in numerous settings but have been confounded by a lack of data regarding shore morphologies prior to installation of these structures. At Yellowstone National Park, there is an opportunity to assess the impacts of shore armor quantitatively because the National Park Service requires …
Climate Drivers And Landscape Response: Holocene Fire, Vegetation, And Erosion At City Of Rocks National Reserve, Idaho, Kerrie N. Weppner
Climate Drivers And Landscape Response: Holocene Fire, Vegetation, And Erosion At City Of Rocks National Reserve, Idaho, Kerrie N. Weppner
Boise State University Theses and Dissertations
Climate exerts primary control over vegetation and fire occurrence but landscape structure, vegetation type, and density determine fire pattern, frequency and severity (i.e., fire regime), and the nature of fire-related geomorphic response. To explore these relationships, we compare alluvial charcoal records of fire and fire-related sedimentation with a woodrat midden reconstruction of vegetation at the northern migration front for single-leaf pinyon and Utah juniper at City of Rocks National Reserve (CIRO), south-central Idaho.
Radiocarbon ages from 37 charcoal macrofossils sampled from discrete fire-related deposits indicate five episodes of increased fire activity over the past ~11 ka. Fires burned following deglaciation …
Role Of Vegetation And Environmental Characteristics On Slope Stability In Northwest Arkansas, Michael Maguigan
Role Of Vegetation And Environmental Characteristics On Slope Stability In Northwest Arkansas, Michael Maguigan
Graduate Theses and Dissertations
Slope failure continues to pose risks to society because knowledge of environmental factors and their interactions are unclear and possibly misunderstood. This misunderstanding leads to generalizations about slope failure susceptibility mapping, despite knowing that slope failures are likely the result of an extensively complex set of interactions among a number of environmental, edaphic, and geomorphic characteristics. Therefore a series of experiments were conducted to investigate the effects of slope, soil texture, vegetation cover, bedrock permeability, and compaction,. A wooden flume with a slope face 1 m wide by 1.5 m long with a 10 cm toe was constructed to contain …
Geoarchaeology Of The Orontes River Floodplain Surrounding Tell Qarqur, Syria, Anna Flora Wieser
Geoarchaeology Of The Orontes River Floodplain Surrounding Tell Qarqur, Syria, Anna Flora Wieser
Graduate Theses and Dissertations
This project combines geoarchaeological soil description and GIS analysis of archaeological site distribution to investigate the history of marsh formation in the northern Ghab Basin, located within the Orontes River Valley of western Syria. Tell Qarqur, the archaeological site around which this project is focused, has a continuous occupational sequence throughout the Holocene. Annual inundation of the site by seasonal marshlands suggests that the marsh was either smaller or non-existent in the past, but its history remains unknown. The objectives of this investigation are to interpret the nature of depositional environments, particularly fluvial action, in the vicinity of Tell Qarqur, …
Experimental Simulations Of Dark Slope Streaks On Mars, Kelly Howe
Experimental Simulations Of Dark Slope Streaks On Mars, Kelly Howe
Graduate Theses and Dissertations
Martian slope streaks were first observed in Viking images but their formation still remains ambiguous. Martian slope streaks are currently occurring geological phenomenon on Mars, which requires any formation theory to be in agreement with Mar's current temperature and pressure conditions. Planar morphology of martian slope streaks suggest a potential fluvial formation, but current conditions on Mars are not conducive to water remaining liquid long enough to erode the surface. Debris flows, fluid stains and dry dust avalanches have all been previously cited as a potential formation mechanism for martian slope streaks. Recent experimental simulations indicate that a fluvial source …
The Fluvial Muddy Creek Formation Near Overton, Nevada, Carl Taylor Swenberg
The Fluvial Muddy Creek Formation Near Overton, Nevada, Carl Taylor Swenberg
UNLV Theses, Dissertations, Professional Papers, and Capstones
The Muddy Creek Formation (MCF) may represent an ancestral Colorado River deposit. To test this hypothesis, I mapped exposures of the MCF within the Virgin River Depression (VRD), a rift basin in the central Basin and Range. This is the first study to analyze fluvial MCF facies and test their viability as ancestral Colorado River deposits.
Mapping, paleocurrent analysis, conglomerate provenance, and architectural elements analysis were used in order to characterize the fluvial MCF near Overton NV. Architectural elements analysis revealed that MCF fluvial facies are most closely associated with those of a high-energy sand-bed braided river system. These results …
Reservoir Potential Of Sands Formed In Glaciomarine Environments: An Analog Study Based On Cenozoic Examples From Mcmurdo Sound, Antarctica, Christopher R. Fielding, Brian A. Blackstone, Tracy D. Frank, Zi Gui
Reservoir Potential Of Sands Formed In Glaciomarine Environments: An Analog Study Based On Cenozoic Examples From Mcmurdo Sound, Antarctica, Christopher R. Fielding, Brian A. Blackstone, Tracy D. Frank, Zi Gui
Department of Earth and Atmospheric Sciences: Faculty Publications
This paper provides documentation of unexpectedly high-reservoir-quality glaciomarine sands found in the Cenozoic succession beneath McMurdo Sound, Antarctica, as an analogue study for evaluations of hydrocarbon prospectivity in basins elsewhere. The Oligocene to Lower Miocene succession of the Victoria Land Basin, an extant portion of the West Antarctic Rift System, comprises diamictites, mudrocks, and sandstones with minor conglomerates. These lithologies are arranged in repetitive stacking patterns (cycles), interpreted to record repeated advance and retreat of glaciers into and out of the basin, with attendant eustatic and isostatic effects. Phases of ice retreat within the cycles comprise an array of mudrocks, …
Evaluating Geomorphic Change In Little Creek Using Repeated Cross-Sectional And Longitudinal Profile Surveys, Drew Allen Perkins
Evaluating Geomorphic Change In Little Creek Using Repeated Cross-Sectional And Longitudinal Profile Surveys, Drew Allen Perkins
Master's Theses
Six geomorphic study reaches were established in 2002 along a forested mountain stream (gradients range from 0.02 to 0.05) on Cal Poly's Swanton Pacific Ranch in Santa Cruz County, California. These study reaches are a component of paired and nested watershed studies in the approximately 500 hectare Little Creek watershed. The overall goal of this study was to monitor water quality and channel conditions before, during, and after a selective harvest of redwood. A selective harvest occurred in the North Fork of Little Creek in Summer 2008. In August 2009, approximately 90% of the Little Creek Watershed was burned in …
Vent-Fault Spatial Study Of Selected Volcanic Fields Of Southwestern North America And Mexico, Michelle Leonard
Vent-Fault Spatial Study Of Selected Volcanic Fields Of Southwestern North America And Mexico, Michelle Leonard
USF Tampa Graduate Theses and Dissertations
Of fundamental concern in volcanic hazard and risk assessment studies of volcanic systems is what role crustal structures might play in the ascent of magma through the crust. What are the processes that govern the spatial distribution and timing of eruptions, especially in populated areas or near sensitive facilities? Many studies have drawn the conclusion that faults play a critical role as easily–exploitable crustal weaknesses along which magma can ascend. Great care must be used when assuming a causative relationship between patterns of vents and faults especially when such relationships may be incorporated into hazard assessment models or other forecasting …
Soil Mapping On A Swanton Pacific Ranch Rangeland, Thomas N. Witman
Soil Mapping On A Swanton Pacific Ranch Rangeland, Thomas N. Witman
Natural Resources Management and Environmental Sciences
Knowledge of soils has become very important in most land based enterprises. The understanding of soils is necessary for all different types of land management projects. The USDA mapped all of the soils in the United States starting in the late 1950’s to provide the necessary information. However because the mappers often times had to map entire counties in short amounts of time ,did not have modern technology, and had rather a vague operating procedure, there was no way to be accurate on the small scaled. To solve this problem I evaluated Dr. Ron Taskey’s landscape hierarchy, a method that …
Three-Dimensional Hydrostratigraphy Of The Platte River Valley Near Ashland, Nebraska: Results From Helicopter Electromagnetic (Hem) Mapping In The Eastern Nebraska Water Resources Assessment (Enwra), P. R. Hanson, Jesse T. Korus, Dana Divine
Three-Dimensional Hydrostratigraphy Of The Platte River Valley Near Ashland, Nebraska: Results From Helicopter Electromagnetic (Hem) Mapping In The Eastern Nebraska Water Resources Assessment (Enwra), P. R. Hanson, Jesse T. Korus, Dana Divine
Conservation and Survey Division: Faculty and Staff Publications
No abstract provided.
Exploring The Role Of Organic Matter Accumulation On Delta Evolution, Jorge Lorenzo Trueba, Vaughan Voller, Chris Paola, Robert Twilley, Azure Bevington
Exploring The Role Of Organic Matter Accumulation On Delta Evolution, Jorge Lorenzo Trueba, Vaughan Voller, Chris Paola, Robert Twilley, Azure Bevington
Department of Earth and Environmental Studies Faculty Scholarship and Creative Works
We explore the role of plant matter accumulation in the sediment column in determining the response of fluvial-deltas to base-level rise and simple subsidence profiles. Making the assumption that delta building processes operate to preserve the geometry of the delta plain, we model organic sedimentation in terms of the plant matter accumulation and accommodation (space made for sediment deposition) rates. A spatial integration of the organic sedimentation, added to the known river sediment input, leads to a model of delta evolution that estimates the fraction of organic sediments preserved in the delta. The model predicts that the maximum organic fraction …
Gordon Natural Area, West Chester University, 1937 Aerial Photograph, West Chester University Of Pennsylvania
Gordon Natural Area, West Chester University, 1937 Aerial Photograph, West Chester University Of Pennsylvania
Gordon Natural Area Soils Studies Documents
No abstract provided.
Gordon Natural Area, West Chester University, 1 Meter Contour Map, West Chester University Of Pennsylvania
Gordon Natural Area, West Chester University, 1 Meter Contour Map, West Chester University Of Pennsylvania
Gordon Natural Area Soils Studies Documents
No abstract provided.
Evolution With Depth From Detrital To Authigenic Smectites In Sediments From And-2a Drill Core (Mcmurdo Sound, Antarctica), Francesco Iacoviello, Giovanna Giorgetti, Fernando Nieto, Isabella Turbanti Memmi
Evolution With Depth From Detrital To Authigenic Smectites In Sediments From And-2a Drill Core (Mcmurdo Sound, Antarctica), Francesco Iacoviello, Giovanna Giorgetti, Fernando Nieto, Isabella Turbanti Memmi
ANDRILL Research and Publications
We have examined the nature and origin of smectites in glaciomarine sediments of the AND-2A drill core (McMurdo Sound, Antarctica) by means of X-ray diffraction (XRD) analyses on the clay fraction, field emission scanning electron microscopy (FESEM), scanning electron microscopy (SEM) observations and SEM-EDS microanalyses on smectite particles. Relying on the smectite variation throughout the drill core it was possible to split the sequence into three units. Smectites throughout the core are either detrital or authigenic. Detrital smectites are close to montmorillonite-beidellite in composition while newly-formed smectites frequently have higher Fe-Mg contents and intermediate compositions between the saponite and nontronite …
Gordon Natural Area, West Chester University, 2012 Aerial Photograph, West Chester University Of Pennsylvania
Gordon Natural Area, West Chester University, 2012 Aerial Photograph, West Chester University Of Pennsylvania
Gordon Natural Area Soils Studies Documents
No abstract provided.
Gordon Natural Area, West Chester University, Lidar Image, West Chester University Of Pennsylvania
Gordon Natural Area, West Chester University, Lidar Image, West Chester University Of Pennsylvania
Gordon Natural Area Soils Studies Documents
No abstract provided.
Three-Dimensional Hydrostratigraphy Of The Sprague, Nebraska Area: Results From Helicopter Electromagnetic (Hem) Mapping For The Eastern Nebraska Water Resources Assessment (Enwra), Dana Divine, Jesse T. Korus
Three-Dimensional Hydrostratigraphy Of The Sprague, Nebraska Area: Results From Helicopter Electromagnetic (Hem) Mapping For The Eastern Nebraska Water Resources Assessment (Enwra), Dana Divine, Jesse T. Korus
Conservation and Survey Division: Faculty and Staff Publications
No abstract provided.
Assessment Of Coal Geology, Resources, And Reserves In The Montana Powder River Basin, Jon E. Haacke, David C. Scott, Lee M. Osmonson, James A. Luppens, Paul E. Pierce, Jay A. Gunderson
Assessment Of Coal Geology, Resources, And Reserves In The Montana Powder River Basin, Jon E. Haacke, David C. Scott, Lee M. Osmonson, James A. Luppens, Paul E. Pierce, Jay A. Gunderson
United States Geological Survey: Publications
The purpose of this report is to summarize geology, coal resources, and coal reserves in the Montana Powder River Basin (MTPRB) assessment area in southeastern Montana. This report represents the fourth assessment area within the Powder River Basin to be evaluated in the continuing U.S. Geological Survey regional coal assessment program.
There are four active coal mines in the MTPRB assessment area: the Spring Creek and Decker Mines, both near Decker; the Rosebud Mine, near Colstrip; and the Absaloka Mine, west of Colstrip. During 2011, coal production from these four mines totaled approximately 36 million short tons (MST). A fifth …
Effectiveness Of Four Water-Bearing Zones Of The Glacierized Basin In Meltwater Runoff Modeling, Umesh K. Haritashya
Effectiveness Of Four Water-Bearing Zones Of The Glacierized Basin In Meltwater Runoff Modeling, Umesh K. Haritashya
Department of Earth, Environment and Sustainability Faculty Publications
Meltwater runoff modeling from glacierized basins needs several input data, including total meltwater contributing area. This study utilizes optical remote sensing data to assess glacierized basins in the central Himalayas where snow and glaciers contribute substantially to the water resources. Result shows that there are four main water-bearing zones in the basin: (a) dry snow, (b) wet snow, (c) exposed glacial ice, and (d) debris-covered glacial ice, and it is possible to differentiate and map these zones and their spatio-temporal variations from satellite sensor data. These zones can then be incorporated in meltwater runoff modeling as separate entities because they …
Trap Efficiency Of A Silted Prairie Reservoir: Rapidan Reservoir, Blue Earth County, Minnesota, Katherine Brosch Rassmussen
Trap Efficiency Of A Silted Prairie Reservoir: Rapidan Reservoir, Blue Earth County, Minnesota, Katherine Brosch Rassmussen
All Graduate Theses, Dissertations, and Other Capstone Projects
Rapidan Dam and Reservoir are located along the Blue Earth River south of Mankato, Minnesota. The dam was constructed in 1911 as a source of hydroelectric power to supplement the surroundings communities. Currently, the reservoir is heavily silted and provides little hydroelectric benefit while proving costly to maintain. This study (1) defines the sedimentary, geomorphic, stream flow and suspended load characteristics of the reservoir for 2008-2009 and (2) compares these parameters with those available from 1985 (23 years prior). Stream gauging and sediment sampling took place in 2008 and 2009 at three monitoring locations (two upstream and one downstream of …
Holocene Arroyo Cut And Fills Cycles, South-Central Washington, Matthew Ian Durkee
Holocene Arroyo Cut And Fills Cycles, South-Central Washington, Matthew Ian Durkee
All Master's Theses
Ephemeral streams have cut deeply incised arroyos into alluvial and eolian sediments in many of the watersheds within the Yakima Training Center (YTC) military reservation, south-central Washington. The most recent channel incision episode along Selah Creek is primarily attributed to multiple failures of an irrigation reservoir dam during the winters of 1909 and 1910. The modern arroyo exposed evidence of at least one previous episode of arroyo incision to a depth of ~4 m that occurred just prior to 1530- 1340 cal yr BP. Filling of this paleo-arroyo with fine to coarse grained sand ceased between 650-103 cal yr BP. …
Documenting Magma Evolution Of The Fossa Delle Felci (Salina Island, South Tyrrhenian Sea) By Integrating In Situ Plagioclase Data With Quantitative Modeling, Aaron Mayfield
All Master's Theses
Compositional diversity occurs via processes dominated by recharge, assimilation and fractional crystallization (RAFC), quantification of which can provide insights into eruption catalysts, and therefore assist in hazard mitigation. This study evaluates the relative roles of RAFC processes in Fossa delle Felci (Salina Island, Italy) magmas, which span the basalt to dacite range (52-65 wt% SiO2). Integration of petrographic, whole rock, and in situ plagioclase data with quantitative magma chamber models suggests differentiation dominated by fractional crystallization and magma recharge/mixing in reservoirs located at different crustal levels. At ~12 km depth, magma evolved through crystallization of a pyroxene dominated assemblage; plagioclase …
Petrogenetic Relationship Of The Postcaldera Eruptions Of Mount Mazama, Crater Lake, Oregon; Evolution Of A Sub-Volcanic Magma Chamber Following A Large Silicic Eruption, Michelle Leanna Tebbe
Petrogenetic Relationship Of The Postcaldera Eruptions Of Mount Mazama, Crater Lake, Oregon; Evolution Of A Sub-Volcanic Magma Chamber Following A Large Silicic Eruption, Michelle Leanna Tebbe
All Master's Theses
Mount Mazama is the volcanic edifice that cataclysmically erupted ~503 km of relatively homogeneous rhyodacite lava ~ 7,700 years ago, forming the caldera known as Crater Lake. Within a few hundred years, andesitic eruptions built three distinct volcanic edifices on the floor of Crater Lake; ~ 3000 years later, rhyodacite eruptions formed a dome (Bacon et al., 2002). How magmatic systems evolve following a shallow, relatively large silicic eruption is the focus of this study. In situ geochemical analysis coupled with high-resolution textural images of plagioclase crystals in the four postcaldera volcanic edifices were used to identify distinct crystal populations …