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Articles 661 - 690 of 1564

Full-Text Articles in Earth Sciences

Structural Analysis Of Co2 Leakage Through The Salt Wash And Little Grand Wash Faults From Natural Reservoirs In The Colorado Plateau, Southeastern Utah, Anthony P. Williams May 2004

Structural Analysis Of Co2 Leakage Through The Salt Wash And Little Grand Wash Faults From Natural Reservoirs In The Colorado Plateau, Southeastern Utah, Anthony P. Williams

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

The Little Grand Wash fault and the Salt Wash Graben in the Colorado Plateau of southeastern Utah emit CO2 gas from abandoned drillholes, springs, and a hydrocarbon seep. Similar CO2-charged water has also been emitted in the past, as shown by large localized travertine deposits and veins along and near the fault traces. The faults cut natural CO2 reservoirs and provide an excellent analog for geologic CO2 sequestration. The faults cut a north-plunging anticline of rocks consisting of siltstones, shales, and sandstones from the Permian Cutler Formation through the Cretaceous Mancos Shale. The Little Grand …


Spatial Variation In The Response Of Tree Rings To Normal Faulting During The Hebgen Lake Earthquake, Southwestern Montana, Usa, Matthew F. Bekker Apr 2004

Spatial Variation In The Response Of Tree Rings To Normal Faulting During The Hebgen Lake Earthquake, Southwestern Montana, Usa, Matthew F. Bekker

Wasatch Dendroclimatology Research

Tree rings have frequently been used to identify the effects of earthquakes on forests, but little is known about spatial variation in the response of trees to intraplate normal faulting. This paper documents and describes the effects of tree location (distance from and position above or below the fault scarp), size and age on the response of tree rings to the 1959 magnitude 7.5 Hebgen Lake earthquake, which occurred along a normal fault in the Gallatin National Forest in southwestern Montana. Core samples from 88 trees were collected along nine 100-m transects straddling the Hebgen scarp, and from 28 additional …


Habitat Conservation Plan For The Cedar City Golf Course And The Paiute Tribal Lands, Cedar City Corporation, Paiute Tribe Of Utah Jan 2004

Habitat Conservation Plan For The Cedar City Golf Course And The Paiute Tribal Lands, Cedar City Corporation, Paiute Tribe Of Utah

All U.S. Government Documents (Utah Regional Depository)

No abstract provided.


Great Plains Workshop Held To Prepare For Usarray Deployment, Mary S. Hubbard, S. S. Gao, K. H. Liu, K. E. Nicolaysen, C. G. Oviatt Aug 2003

Great Plains Workshop Held To Prepare For Usarray Deployment, Mary S. Hubbard, S. S. Gao, K. H. Liu, K. E. Nicolaysen, C. G. Oviatt

Geosciences Faculty Publications

Relative to most parts of North America, the Great Plains region, which is bordered by the Rocky Mountain Front on the west and the Mississippi River on the east, has been understudied in terms of the structure, formation, and evolution of the underlying crust, mantle, and core. The anticipated arrival of the USArray portable seismic stations, which will cover the entire United States regardless of surface geology and tectonic activities, and the deployment of the accompanying flexible array stations and the permanent seismic stations in this area, will fill this gap and address numerous problems related to the structure and …


Field Testing Of Abrasion Resistant Carbides, Kevin C. Orme May 2003

Field Testing Of Abrasion Resistant Carbides, Kevin C. Orme

Undergraduate Honors Capstone Projects

Chromium, tungsten, titanium, and vanadium carbides were investigated to determine relative cost of operation for each in an agricultural environment. For use on a ripper plow, these carbides were field tested in two different soil types; one soil having a matrix of gravel and cobblestones, and the other consisting of hard dirt and large underground rocks. Each alloy was applied to a high carbon plow point using an arc welding process. Along with the welded points, cast chromium carbide was tested. The results are given in price per acre and not solely longevity of the point. It was concluded that …


From The Rim To The River: The Geomorphology Of Debris Flows In The Green River Canyons Of Dinosaur National Monument, Colorado And Utah, Isaac J. Larsen May 2003

From The Rim To The River: The Geomorphology Of Debris Flows In The Green River Canyons Of Dinosaur National Monument, Colorado And Utah, Isaac J. Larsen

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

The Green River canyons of the eastern Uinta Mountains have experienced a 5-year period of high debris flow activity. Catchment factors were studied in watersheds and on debris fans with recent debris flows, leading to the development of a conceptual framework of the hillslope and debris flow processes that deliver sediment to the Green River. Two recent fan deposits were monitored to determine the magnitude and processes of reworking that occur during mainstem floods of varying magnitude.

The dominant debris flow initiation mechanism, termed the firehose effect, occurs when overland flow generated on bedrock slopes cascades down steep cliffs and …


Using Geographic Information Systems And Remote Sensing To Analyze Fire Likelihood Areas At The Regional Scale In The Western United States, Russell W. Reading May 2003

Using Geographic Information Systems And Remote Sensing To Analyze Fire Likelihood Areas At The Regional Scale In The Western United States, Russell W. Reading

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

Geographic Information Systems (GIS) are increasingly used to examine fire activity. This study uses GIS to determine fire likelihood probabilities at an intermediate scale ( I-kilometer) on a daily basis given readily available data. Layers used for the analysis included slope, aspect, elevation, fuel type, proximity to existing fires, maximum temperature, minimum temperature, relative humidity, average vapor pressure deficit, precipitation, 1-hour fuel moisture, and 10-hour fuel moisture.

There were three objectives of this study: 1. Establish a correlation between burn perimeters and readily available topographic and environmental data, and map the spatial distribution of these as fire likelihood areas; 2. …


Evaluation Of Chela Formation In Kambala-Livuite Area, Southern Block 0, Cabinda, Angola, Alba B. Bias Dos Santos May 2003

Evaluation Of Chela Formation In Kambala-Livuite Area, Southern Block 0, Cabinda, Angola, Alba B. Bias Dos Santos

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

The abundance of good reservoir and source rocks offshore Cabinda, Angola, makes the area an attractive and successful hydrocarbon province. Block 0, offshore Cabinda, lies in the Lower Congo basin along the western coast of Africa. The stratigraphy of Block 0 consists of two major oil-rich sequences: the rift sequence (primarily lacustrine) and the post-rift sequence (primarily marine). These are separated by a thick section of evaporites, and thus are referred to as the pre-salt sequence and post-salt sequence, respectively.

The Chela Formation, mid-Aptian in age, was deposited before the salt. It consists of sandstones and conglomerates locally interbedded with …


Mitigation, Monitoring, And Geomorphology Related To Gully Erosion Of Archaeological Sites In Grand Canyon, Paul A. Petersen May 2003

Mitigation, Monitoring, And Geomorphology Related To Gully Erosion Of Archaeological Sites In Grand Canyon, Paul A. Petersen

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

Gully erosion has been damaging archaeological sites in Grand Canyon during the last several decades, and there is a need to protect these features through mitigation, monitoring, and better geomorphic understanding. The purpose of this study was to assess the effectiveness of erosion-control structures, determine the accuracy and utility of aerial photogrammetry for monitoring gullies, and understand the geomorphology of the erosion. We performed total-station surveys and other data collection during February and October, 2002, at nine study sites in eastern and western Grand Canyon.

Erosion-control structures are more prone to be damaged by flow when they are placed in …


Quaternary Geology And Landscape Evolution Of Eastern Grand Canyon, Arizona, Matt D. Anders May 2003

Quaternary Geology And Landscape Evolution Of Eastern Grand Canyon, Arizona, Matt D. Anders

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

Tectonics and drainage evolution are controlling overall landscape incision in eastern Grand Canyon. Superimposed on downcutting are dynamic responses of hillslopes, tributary streams, and the Colorado River to glacial-interglacial climate cycles. Five tributary stream fill terraces have been identified, and luminescence dating indicates aggradation was occurring 50- 34 ka {S3), 12-7 ka (S2), and 5-3.5 ka (S1). Seven Colorado River fill terraces have been identified, and luminescence and U-series dating indicate deposition was occurring 343-322 ka (M5), 151-118 ka (M4), and 71-64 ka (M3).

Aggradation by the Colorado River in eastern Grand Canyon begins during glacial advances and continues into …


Simulation Of Groundwater Flow In Cache Valley, Utah And Idaho, Barry Myers May 2003

Simulation Of Groundwater Flow In Cache Valley, Utah And Idaho, Barry Myers

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

A groundwater model of Cache Valley was created using MODFLOW. Steady-state calibration of the model demonstrated that recharge to the lower confined aquifer may occur along the margin of the valley that borders the Wellsville Mountains and the Bear River Range. Steady-state calibration also showed that discharge from the unconfined aquifer may occur along the eastern and western margins of the valley in both the Utah and the Idaho portions of the valley.

Two simulations were run with increased pumping of 3 5 cubic feet per second (1 cubic meter per second) from the principal aquifer. The first simulation was …


Characteristics, Evolution, And Lateral Variation Of Lower Cretaceous Supradetachment Basins In The Daqing Shan, Inner Mongolia, China, Adrian K. Berry May 2003

Characteristics, Evolution, And Lateral Variation Of Lower Cretaceous Supradetachment Basins In The Daqing Shan, Inner Mongolia, China, Adrian K. Berry

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

Lower Cretaceous basins associated with the Hohhot detachment in the Daqing Shan of Inner Mongolia, China, allow us to better understand the tectonic evolution of extensional basins formed in association with detachment faulting and metamorphic core complex formation. The six basins, informally named N1, N2, S1, S2, S3, and S4, are located in different structural settings, or depozones, throughout the detachment-metamorphic core complex setting, and although all basins are consistent with previously proposed models for supradetachment basin sedimentation, second-order variability in sedimentary style is exerted by these distinct structural settings. The basins are composed of coarse, predominantly footwall derived, conglomerate …


Geology Of The Deseret Peak East 7.5' Quadrangle, Tooele County, Utah, And Impacts For Hydrology Of The Region, Torrey J. Copfer May 2003

Geology Of The Deseret Peak East 7.5' Quadrangle, Tooele County, Utah, And Impacts For Hydrology Of The Region, Torrey J. Copfer

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

Detailed geologic mapping of the Deseret Peak East 7.5' Quadrangle yields new interpretations regarding the stratigraphy of the Oquirrh Basin, fault and fold geometry, and structural evolution of the region. The Stansbury Range consists of the north-south-trending Deseret anticline. Basal Mississippian units rest unconformably on Cambrian beds in the central part of the range. Paleozoic uplift, Mesozoic contraction, and Cenozoic extension have created a series of broad folds, large thrust faults, and several normal faults.

The area is dominated by bedrock springs, with the presence of abundant and thick Quaternary deposits unrelated to Pleistocene glaciation, burying drainages, and mantling hillslopes. …


One-Dimensional Modeling Of Bromide Tracer And Trichloroethylene Transport Based On Laboratory Experiments In Vertical Soil Columns, Keri L. Murch May 2003

One-Dimensional Modeling Of Bromide Tracer And Trichloroethylene Transport Based On Laboratory Experiments In Vertical Soil Columns, Keri L. Murch

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

Enhanced biodegradation using carbon donor and microbial addition is being considered as a possible remediation technique for a trichloroethylene (TCE) contaminated area in Sunset, Utah, west of the source area on Hill Air Force Base. As a precursor to any in situ remediation attempts, several laboratory treatability experiments are being conducted, including the construction of microcosms and flow-through columns. Nine large-scale flow-through columns were built using site groundwater and aquifer material. Bromide tracer tests were conducted to establish and understand the hydraulic conditions within the columns prior to the commencement of the TCE biodegradation experiments. Four predictive models were created …


Validation Of A Radiometric Normalization Procedure For Satellite-Derived Imagery Within A Change Detection Framework, Karin E. Callahan May 2003

Validation Of A Radiometric Normalization Procedure For Satellite-Derived Imagery Within A Change Detection Framework, Karin E. Callahan

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

Detecting changes in land cover through time using remotely sensed imagery is a powerful application that has seen increased use as imagery has become more widely available and inexpensive. Before a time series of remotely sensed imagery can be used for change detection, images must first be standardized for effects outside of real surface change. This thesis established a validation protocol to evaluate the effectiveness of an automated technique for normalizing temporally separate but spatially coincident imagery. Using the concept of pseudo-invariant features between master-slave image pairs, spatially coincident dark and bright points are identified from images and a regression …


The Middle Cambrian Wheeler Formation: Sequence Stratigraphy And Geochemistry Across A Ramp-To-Basin Transition, Elizabeth S. Langenburg May 2003

The Middle Cambrian Wheeler Formation: Sequence Stratigraphy And Geochemistry Across A Ramp-To-Basin Transition, Elizabeth S. Langenburg

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

The Middle Cambrian Wheeler Formation is interpreted as having been deposited in the shallow ramp and deeper basin environments of the House Range embayment (HRE), presumably, during a single third-order sequence. In the Drum Mountains, the Wheeler Formation (295 m thick) is dominated by proximal and distal ramp deposits; at Marjum Pass, the Wheeler Formation (190m thick) is dominated by basinal shale deposits. The Wheeler Formation contains only one biozone marker; the first appearance of Ptyhagnostus atavus. Lack of other chronostratigraphic markers and distinctive stratal patterns in the basinal facies makes correlation along this ramp-to-basin transect difficult. Therefore, carbon-isotope …


Soil Survey Of Grand Staircase- Escalante National Monument Area, Parts Of Kane And Garfield Counties, Utah, United States Department Of Agriculture, Natural Resources Conservation Service Jan 2003

Soil Survey Of Grand Staircase- Escalante National Monument Area, Parts Of Kane And Garfield Counties, Utah, United States Department Of Agriculture, Natural Resources Conservation Service

All U.S. Government Documents (Utah Regional Depository)

This soil survey contains information that affects land use planning in this survey area. It contains predictions of soil behavior for selected land uses. The survey also highlights soil limitations, improvements needed to overcome the limitations and the impact of selected land uses on the environment. This soil survey is designed for many different users. Farmers, ranchers, foresters and agronomists can use it to evaluate the potential of the soil and the management needed for maximum food and fiber production. Planners, community officials, engineers, developers, builders and home buyers can use the survey to plan land use, select sites for …


Hydrologic Properties And Structure Of The Mozumi Fault, Central Japan, Craig B. Forster, James P. Evans, Hidemi Tanaka, Ronald Jeffreys, Tsuyoshi Nohara Jan 2003

Hydrologic Properties And Structure Of The Mozumi Fault, Central Japan, Craig B. Forster, James P. Evans, Hidemi Tanaka, Ronald Jeffreys, Tsuyoshi Nohara

Geosciences Faculty Publications

Analyses of rocks from the Active Fault Survey Tunnel (AFST) provides insight into the structure and hydrogeology of the northeast-trending Mozumi-Sukenobu fault, an active strike-slip fault with 125 to 500 m of right-lateral slip in central Japan. Interlayered regions of sub-vertical permeability zones formed by cataclasis and slip on clay-rich foliated zones. Core samples range from 10−19 m2 to almost 10−13 m2. CFC analyses of waters from the fault zone show that water entering the tunnel is 27–36 years old, yielding a bulk fault permeability of 10−14 to 10−15 m2. The …


Extensional Folds Associated With Paleogene Detachment Faults In Se Part Of The Salmon Basin, Susanne U. Janecke, J. C. Blankenau Jan 2003

Extensional Folds Associated With Paleogene Detachment Faults In Se Part Of The Salmon Basin, Susanne U. Janecke, J. C. Blankenau

Geosciences Faculty Publications

No abstract provided.


Late Miocene-Pliocene Detachment Faulting And Pliocene-Recent Basin-And-Range Extension Inferred From Dismembered Rift Basins Of The Salt Lake Formation, Se Idaho, Susanne U. Janecke, S. M. Carney, M. E. Perkins, J. C. Evans, P. K. Link, R. Q. Oaks Jr., B. P. Nash Jan 2003

Late Miocene-Pliocene Detachment Faulting And Pliocene-Recent Basin-And-Range Extension Inferred From Dismembered Rift Basins Of The Salt Lake Formation, Se Idaho, Susanne U. Janecke, S. M. Carney, M. E. Perkins, J. C. Evans, P. K. Link, R. Q. Oaks Jr., B. P. Nash

Geosciences Faculty Publications

Geologic mapping, basin analysis, and tephra correlations in the Clifton and Malad City East 7.5-minute quadrangles in southeastern Idaho indicate that the modern Basin-and-Range topography is only a few million years old and was superimposed on unrelated rift basins associated with the ~12 to < 4 Ma Bannock detachment system. The Miocene-Pliocene Salt Lake Formation in the greater Cache Valley area was deposited during three sub-episodes of west-southwest extension on the Bannock detachment system.

Depositional systems within the Salt Lake Formation (>10.27 ± 0.07 Ma to < 5.1-4.4 Ma) evolved in response to the changing structural configuration of rift basins in the hanging wall of the Bannock detachment system. Early alluvial fans derived from the underlying Paleozoic rocks were replaced by broad, saline/alkaline lakes during the translation phase on the detachment fault. Later, as the hanging wall broke up internally, freshwater lakes and deltas occupied newly created NE-tilted half graben, and eventually filled them with braided streams. The Bannock detachment system collapsed the Cache-Pocatello Culmination of the dormant Sevier fold-and-thrust belt, much like the Sevier Desert Detachment collapsed the Sevier Culmination and the Wasatch Fault collapsed the Wasatch Culmination.

Deposition and tilting of the Salt Lake Formation ceased in the middle to late Pliocene (< 2 >Ma?) before uplift of the Clifton Horst along a new system of Basin-and-Range normal faults. This later episode of normal faulting uplifted and exposed metamorphic rocks in …


Hill Air Force Base: Archaeological Monitoring Of Target And Access Road Development For The Ts-5-2 Target Area, Utah Test And Training Range, Tooele County, Utah, Daron Duke Jun 2002

Hill Air Force Base: Archaeological Monitoring Of Target And Access Road Development For The Ts-5-2 Target Area, Utah Test And Training Range, Tooele County, Utah, Daron Duke

All U.S. Government Documents (Utah Regional Depository)

The U.S. Army Corps of Engineers, Fort Worth District, contracted with Geo-Marine, Inc., to conduct archaeologial monitoring for a U.S. Air Force Air Combat Command (ACC) project on the Utah Test and Training Range (UTTR), which is under the jurisdiction of Hill Air Force Base and located in Tooele County, western Utah. Monitoring of ground disturbing activities associated with ACC development of Target TS-5-2 and a 2.5-mile dirt access road on the TS-5 (Wild Isle) area of UTTR was undertaken in January 2001. Additional target and access road development monitoring was conducted in July and August of 2001, and the …


Bioavailability/Toxicity Of Iron From Aerobically Processed Organic Fertilizer, Stacey Marie Wilson May 2002

Bioavailability/Toxicity Of Iron From Aerobically Processed Organic Fertilizer, Stacey Marie Wilson

Undergraduate Honors Capstone Projects

For an undergraduate Honor's project, I worked under the direction of Dr. Jeffery Hall to determine the bioavailability and toxicity of iron from Milorganite® fertilizer, an aerobically processed organic fertilizer. The Milorganite® Company is a subsidiary of the Milwaukee Municipal Sewage District and produces a fertilizer of high iron content (approximately 5-7%). The high iron content has resulted in concern about the toxic potential, which until now was unknown. This thesis paper will explain iron chemistry, bioavailability, requirements, absorption, toxicity, and treatments, followed by a description of fertilizer types and contents. This will be followed by a description and reasoning …


Evolution Of A Miocene-Pliocene Low-Angle Normal-Fault System In The Southern Bannock Range, Southeast Idaho, Stephanie M. Carney May 2002

Evolution Of A Miocene-Pliocene Low-Angle Normal-Fault System In The Southern Bannock Range, Southeast Idaho, Stephanie M. Carney

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

Geologic mapping, basin analysis, and tephrochronologic analysis in the Clifton quadrangle of southeast Idaho indicates that the modern Basin-and-Range topography is only a few million years old and that the bulk of Cenozoic extension was accommodated by slip on an older low-angle normal-fault system, the Bannock detachment system. The detachment system was active between ~12 and < 4 Ma and accommodated ~50 % extension.

Cross-cutting relationships show that the master detachment fault, the Clifton fault, is the youngest low-angle normal fault of the system, was active at a low angle, and has not been rotated to a low-dip angle through time. Map patterns and relationships indicate that the …


Geology Of The Cuesta Ridge Ophiolite Remnant Near San Luis Obispo, California: Evidence For The Tectonic Setting And Origin Of The Coast Range Ophiolite, Cameron A. Snow May 2002

Geology Of The Cuesta Ridge Ophiolite Remnant Near San Luis Obispo, California: Evidence For The Tectonic Setting And Origin Of The Coast Range Ophiolite, Cameron A. Snow

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

The Cuesta Ridge ophiolite is one of the best-preserved remnants of mid-Jurassic ophiolite in California. Geologic mapping and petrologic studies show that it comprises (1) harzburgite mantle tectonite, (2) dunite-rich mantle transition zone (MTZ), (3) wehrlite and pyroxenite, (4) isotropic gabbro, (5) sheeted dike/sill complex, (6) volcanic rocks (7) late-stage dikes and flows, and (8) tuffaceous radiolarian chert.

The sheeted dike/sill complex is dominated by quartz diorite, with significant modal quartz and hornblende. The volcanic section is dominated by arc tholeiite and boninitic lavas. Boninites, with high MgO, Cr, and Ni comprise 40% of the volcanic rocks. Latestage dikes and …


Stratigraphy And Paleoecology Of The Morrison Formation, Como Bluff, Wyoming, Melissa V. Connely May 2002

Stratigraphy And Paleoecology Of The Morrison Formation, Como Bluff, Wyoming, Melissa V. Connely

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

The Morrison Formation at Como Bluff, Wyoming, has been historically known for containing a rich source of Late Jurassic vertebrate fossils. However, when collected, most of these fossils were not positioned into a stratigraphic or sedimentologic framework. Research shows that the Morrison Formation at Como Bluff can be divided into three members. These members can be identified by lithologic and paleontological characteristics. The lower Morrison members include the Windy Hill Member and the recently described Lake Como Member. The Windy Hill Member primarily contains near-shore marine sandstone. Megavertebrate fauna is lacking. The Lake Como Member contains illitic clay in red …


A Macroterrain Landtype Association Classification Model For The Great Basin, Frank L. Dougher May 2002

A Macroterrain Landtype Association Classification Model For The Great Basin, Frank L. Dougher

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

Three Macroterrain Landtype Association classification models were developed to stratify and categorize Utah's West Desert. These models approached terrain segmentation using an energy-flow paradigm from erosional to transitional to depositional landscape. One model was developed as a slope-backed deterministic model that used slope-threshold limits to discriminate between Landtype Associations. A second model was developed as a stochastic, training-data driven supervised classification, using comparative t-values to classify the landscape to the most similar landtype class. The third model was a probabilistic algorithm, which classified the landscape to the most probable class based on multiple iterations of the stochastic model. These …


Relationships Between Tributary Catchments, Valley-Bottom Width, Debris-Fan Area, And Mainstem Gradient On The Colorado Plateau: A Case Study In Desolation And Gray Canyons On The Green River, Caroline M. Elliott May 2002

Relationships Between Tributary Catchments, Valley-Bottom Width, Debris-Fan Area, And Mainstem Gradient On The Colorado Plateau: A Case Study In Desolation And Gray Canyons On The Green River, Caroline M. Elliott

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

The alluvial forms of the rivers that drain the Colorado Plateau are a product of the water and sediment load that tributaries deliver to the trunk streams. Where the Green and Colorado Rivers cross structural barriers, narrow canyons have been incised. In the steep terrain adjacent to many of these canyons debris flows occur in the catchment basins of tributaries and deliver coarse sediment to the mainstem river corridor. Over time, debris flow deposits have aggraded in trunk stream valleys and created landforms known as debris fans. The sizes of these debris fans are related to the accommodation space available …


Geometry And Physical Properties Of The Chelungpu Fault, Taiwan, And Their Effect On Fault Rupture, Richard V. Heermance May 2002

Geometry And Physical Properties Of The Chelungpu Fault, Taiwan, And Their Effect On Fault Rupture, Richard V. Heermance

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

Rupture of the Chelungpu fault during the September 21, 1999, 7.6 Mwearthquake in Taiwan caused a 90-Jr,m-long surface rupture with variable displacement along strike. Analysis of core from two holes drilled through the fault zone, combined with geologic mapping and detailed investigation from three outcrops, define the fault geometry and physical properties of the Chelungpu fault in its northern and southern regions. In the northern region, the fault dips 45-60° east parallel to bedding and consists of a narrow (1-20 cm) core of dark-gray, sheared clay gouge at the base of a 30-50 m zone of increased fracture …


Structural And Kinematic Evolution Of Eocene-Oligocene Grasshopper Extensional Basin, Southwest Montana, Julie C. Kickham May 2002

Structural And Kinematic Evolution Of Eocene-Oligocene Grasshopper Extensional Basin, Southwest Montana, Julie C. Kickham

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

The Grasshopper basin of southwest Montana is a complex east-dipping graben containing five unconformity-bounded sequences of Tertiary sedimentary rocks. The Eocene-Oligocene basin lies within the northern Rocky Mountain Basin and Range province. Geologic mapping in five and a half 7.5 minute quadrangles indicates that at least three distinct phases of extension characterize the Cenozoic tectonic evolution of Grasshopper basin from approximately 46 Ma to < Ma.

The significant phases of extension in Grasshopper basin were phases 1 and 3. During the first phase of extension (46-27 Ma) the nonplanar Muddy-Grasshopper fault was initiated and 90% of the basin fill was deposited. At …


The Stratigraphic, Sedimentologic, And Paleogeographic Evolution Of The Eocene- Oligocene Grasshopper Extensional Basin, Southwest Montana, Joseph P. Matoush May 2002

The Stratigraphic, Sedimentologic, And Paleogeographic Evolution Of The Eocene- Oligocene Grasshopper Extensional Basin, Southwest Montana, Joseph P. Matoush

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

Grasshopper basin, located in southwest Montana, is an east-tilted graben bounded by the listric Muddy-Grasshopper fault and the Meriwether Lewis fault on the eastern and western margins of the basin, respectively. This basin contains a complex stratigraphy of intertonguing facies comprised of five unconformity-bounded sequences of Tertiary alluvial, flu vial, deltaic, and lacustrine sedimentary and volcanic rocks. Sequence 1 consists of the Challis volcanic Group (Middle Eocene). The sedimentary rocks of the Medicine Lodge beds (Late Eocene-Late Oligocene) represent sequence 2 and approximately 90% of the basin-fill within Grasshopper basin. Sequence 3 consists 11 of the Sedimentary Rocks of Everson …