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Articles 211 - 240 of 507
Full-Text Articles in Geology
Feasibility Of Extending An Artificial Salmon Spawning Stream, Marx Creek Near Hyder, Alaska, Tom Nelson
Feasibility Of Extending An Artificial Salmon Spawning Stream, Marx Creek Near Hyder, Alaska, Tom Nelson
All Graduate Theses and Dissertations, Spring 1920 to Summer 2023
Marx Creek, near Hyder in southeast Alaska, is a groundwater-fed, artificial salmon-spawning stream that was constructed to enhance the habitat of the atypically large chum salmon. The success of the upper Marx Creek has been limited primarily by the infiltration of silty water from the Salmon River through its flood-control dike, which results in a turbid stream environment that is not conducive to salmon spawning.
The purpose of this project was to determine whether baseflow from the groundwater system is sufficient to support a proposed 1,000-foot extension of Marx Creek. The extension would be constructed approximately 500 feet east of …
Examination Of Deformation In Crystalline Rock From Strike-Slip Faults In Two Locations, Southern California, David H. Forand
Examination Of Deformation In Crystalline Rock From Strike-Slip Faults In Two Locations, Southern California, David H. Forand
All Graduate Theses and Dissertations, Spring 1920 to Summer 2023
Damage zones adjacent to or associated with faults are important to the geologic community because of their implications to hazards and their ability to preserve evidence for, and show history of, slip, fluid flow, and deformation associated with large strike-slip faults. We examine two fault zones in southern California where fault zone damage is expressed. We revisit the drilled crystalline core from the Cajon Pass California drill hole, 4 km northeast of the San Andreas fault (SAF), and 1 km north of the Cleghorn fault, to perform a systematic structural analysis of deformation and alteration associated with strike-slip faulting at …
Composition And Structure Of The San Andreas Fault Observatory At Depth (Safod) Phase Iii Whole-Rock Core: Implications For Fault Zone Deformation And Fluid-Rock Interactions, Kelly Keighley Bradbury, James P. Evans
Composition And Structure Of The San Andreas Fault Observatory At Depth (Safod) Phase Iii Whole-Rock Core: Implications For Fault Zone Deformation And Fluid-Rock Interactions, Kelly Keighley Bradbury, James P. Evans
Geosciences Presentations
We examine the composition and texture of whole-rock core from ~ 3 km depth in the San Andreas Fault Observatory at Depth (SAFOD) borehole, which provides a unique opportunity to characterize in situ rock properties of the near-fault environment, and how these properties vary in an area where deformation is accommodated by aseismic creep and high-rates of microseismicity. Detailed petrography and microstructural analyses coupled with X-Ray Diffraction and X-ray Fluorescence techniques are used to describe composition, alteration, and textures.
All samples record multiple generations of cataclastic deformation in a complexly deformed and altered sequence of fine-grained sheared rocks. Localized shears …
Age And Structure Of The San Jacinto And San Felipe Fault Zones And Their Lifetime Slip Rates, Susanne U. Janecke, R. J. Dorsey, B. Belgarde
Age And Structure Of The San Jacinto And San Felipe Fault Zones And Their Lifetime Slip Rates, Susanne U. Janecke, R. J. Dorsey, B. Belgarde
Geosciences Faculty Publications
No abstract provided.
Geophysical Properties Within The San Andreas Fault Zone At The San Andreas Fault Observatory At Depth (Safod) And Their Relationships To Rock Properties And Fault Zone Structure, Tamara N. Jeppson, Kelly Keighley Bradbury, James P. Evans
Geophysical Properties Within The San Andreas Fault Zone At The San Andreas Fault Observatory At Depth (Safod) And Their Relationships To Rock Properties And Fault Zone Structure, Tamara N. Jeppson, Kelly Keighley Bradbury, James P. Evans
Geosciences Faculty Publications
We examine the relationships between borehole geophysical data and physical properties of fault‐related rocks within the San Andreas Fault as determined from data from the San Andreas Fault Observatory at Depth borehole. Geophysical logs, cuttings data, and drilling data from the region 3‐ to 4‐km measured depth of the borehole encompass the active part of the San Andreas Fault. The fault zone lies in a sequence of deformed sandstones, siltstone, shale, serpentinite‐bearing block‐in‐matrix rocks, and sheared phyllitic siltstone. The borehole geophysical logs reveal the presence of a low‐velocity zone from 3190 to 3410 m measured depth with Vp and …
High Geologic Slip Rates Since Early Pleistocene Initiation Of The San Jacinto And San Felipe Fault Zones In The San Andreas Fault System, Southern California, Usa, Susanne U. Janecke, R. J. Dorsey, D. Forand, A. N. Steely, S. M. Kirby, A. T. Lutz, B. A. Housen, B. Belgarde, V. E. Langenheim, T. M. Rittenour
High Geologic Slip Rates Since Early Pleistocene Initiation Of The San Jacinto And San Felipe Fault Zones In The San Andreas Fault System, Southern California, Usa, Susanne U. Janecke, R. J. Dorsey, D. Forand, A. N. Steely, S. M. Kirby, A. T. Lutz, B. A. Housen, B. Belgarde, V. E. Langenheim, T. M. Rittenour
Geosciences Faculty Publications
The San Jacinto right-lateral strike-slip fault zone is crucial for understanding plate-boundary dynamics, regional slip partitioning, and seismic hazards within the San Andreas fault system of southern California, yet its age of initiation and long-term average slip rate are controversial. This synthesis of prior and new detailed studies in the western Salton Trough documents initiation of structural segments of the San Jacinto fault zone at or slightly before the 1.07-Ma base of the Jaramillo subchron. The dextral faults changed again after ca. 0.5–0.6 Ma with creation of new fault segments and folds. There were major and widespread basinal changes in …
Reconciling Holocene Alluvial Records In Buckskin Wash, Southern Utah, Jonathan E. Harvey
Reconciling Holocene Alluvial Records In Buckskin Wash, Southern Utah, Jonathan E. Harvey
All Graduate Theses and Dissertations, Spring 1920 to Summer 2023
Most approaches to interpreting alluvial records in drylands fall into one of two categories: (1) The "arroyo problem," wherein workers study cycles of streambed aggradation and degradation in broad, unconstricted alluvial valleys; and (2) paleoflood hydrology, where alluvial sequences in constricted bedrock canyons are interpreted as paleoflood deposits from streams with stable channel grade and geometry. Both approaches can be valid in their end-member settings, but there is confusion about how the two record types relate in a single drainage. We address this disconnect in Buckskin Wash, an ephemeral stream that consists of a broad alluvial reach draining into a …
Geologic Mapping, Alluvial Stratigraphy, And Optically Stimulated Luminescence Dating Of The Kanab Creek Area, Southern Utah, Michelle Carlene Summa
Geologic Mapping, Alluvial Stratigraphy, And Optically Stimulated Luminescence Dating Of The Kanab Creek Area, Southern Utah, Michelle Carlene Summa
All Graduate Theses and Dissertations, Spring 1920 to Summer 2023
At the turn of the century, Kanab Creek incised 30-meters into its alluvium, leaving behind fluvial terraces and thick basin fill sediments exposed along arroyo walls. Research objectives were to determine the timing and causes of past valley-filling and arroyo-cutting episodes along a 20 km-long reach of Kanab Creek in southern Utah. Fluvial deposits were mapped at the 1:12,000 scale and sediments were described and dated using Optically Stimulated Luminescence (OSL) and radiocarbon dating.
The Kanab Creek valley can be divided into a narrow, upper terraced reach and a broad lower basin fill reach near Kanab, Utah. The most prominent …
Investigations Into Mapping Lava Flows In The Snake River Plain, Idaho, Vinita Ruth Hobson-Broko
Investigations Into Mapping Lava Flows In The Snake River Plain, Idaho, Vinita Ruth Hobson-Broko
All Graduate Plan B and other Reports, Spring 1920 to Spring 2023
The origin of the Snake River plain continues to be debated, but the plume model is most popular at the current time. Some theories, such as meteorite impact, have been excluded, but the remaining theories require more scrutiny.
Various methods of examining phenomena in the Snake River Plain were employed. Unsupervised classification of Landsat ETM data indicates that spectra can be used to differentiate between flows. However, photographs of flows at Craters of the Moon National Monument show wide variations in texture and color within a single flow. Vegetation grows preferentially on the smoother pahoehoe slabs and significantly impacting the …
Using Real-World Data As A Basis For Problem-Based Learning: Investigating Preservation Biases Of Fish In Fossil Butte National Monument, Blair Larsen
All Graduate Plan B and other Reports, Spring 1920 to Spring 2023
This project examined the design and development of an online problem-based learning module to teach earth-system science to K-12 educators. The module revolved around identifying earth sphere (lithosphere, hydrosphere, biosphere and atmosphere) interactions needed to produce mass fish mortality layers found in the Green River Formation at Fossil Butte National Monument. Students investigated the unique earth sphere combinations needed to produce mass fish mortality layers, reflected on the formation of such deposits, and examined the impact of these earth spheres on the earth system. As a supplement to the course, the students also analyzed data on fossils collected from a …
A River Transformed: Historic Geomorphic Changes Of The Lower Rio Grande In The Big Bend Region Of Texas, Chihuahua, And Coahuila, David James Dean
A River Transformed: Historic Geomorphic Changes Of The Lower Rio Grande In The Big Bend Region Of Texas, Chihuahua, And Coahuila, David James Dean
All Graduate Theses and Dissertations, Spring 1920 to Summer 2023
Over the last century, the construction and management of large dams and stream-flow diversions, and periodic drought have resulted in significant declines in stream flow of the lower Rio Grande in the Big Bend region. Reductions in mean annual flow and peak discharge have resulted in channel narrowing by the formation of vertically accreting inset floodplains. Narrowing has been temporarily interrupted by infrequent large dam releases greater than 1000 m3/s that have temporarily widened the channel; however, after each of these events, narrowing has resumed. Prior to 1942, floods of this magnitude occurred approximately once every 4 years …
A Geologic And Hydrochemical Investigation Of The Suitability Of Central Utah's Navajo Sandstone For The Disposal Of Saline Process Water And Co2, Kevin L. Randall
A Geologic And Hydrochemical Investigation Of The Suitability Of Central Utah's Navajo Sandstone For The Disposal Of Saline Process Water And Co2, Kevin L. Randall
All Graduate Theses and Dissertations, Spring 1920 to Summer 2023
Salt water is produced from the Ferron Sandstone Member of the Mancos Shale in central Utah as part of the production of coalbed methane (CBM) and is disposed of by injection predominantly into the Navajo Sandstone between 4,500 feet to 7,300 feet and is considered to be a hazardous waste. Local government agencies are concerned about the potential impacts on shallow groundwater because of this disposal method.
Water samples were gathered from four shallow water-supply wells, and nine salt water disposal (SWD) wells to compare hydrochemistries as an indicator of potential mixing. Shallow water-supply wells are likely recharged by local …
Correlation, Paleogeography, And Provenance Of The Neoproterozoic Eastern Uinta Mountain Group, Goslin Mountain Area, Northeastern Utah, Daniel J. Rybczynski
Correlation, Paleogeography, And Provenance Of The Neoproterozoic Eastern Uinta Mountain Group, Goslin Mountain Area, Northeastern Utah, Daniel J. Rybczynski
All Graduate Theses and Dissertations, Spring 1920 to Summer 2023
Geologic mapping, facies analysis, sedimentary petrography, and detrital zircon analyses of undivided eastern Uinta Mountain Group stratigraphy are presented to better understand the depositional environments and tectonic setting of the Uinta Mountain Group basin. Subdivided units have been modified and correlated from previous work and include the Red Pine Shale, Hades Pass, Crouse Canyon, Outlaw Trail, and Diamond Breaks formations. Three lower-order maximum flooding surfaces associated with the lower Outlaw Trail formation, lower Hades Pass formation, and Red Pine Shale are interpreted. The relative magnitude of each lower-order transgression increases up section along with increasing diversity of palynomorph assemblages found …
Evolution Of The Lower Cretaceous Chifeng Half-Graben Basins, Inner Mongolia, China, Scott Joshua Friedman
Evolution Of The Lower Cretaceous Chifeng Half-Graben Basins, Inner Mongolia, China, Scott Joshua Friedman
All Graduate Theses and Dissertations, Spring 1920 to Summer 2023
As a result of complex extensional tectonics in northeast China and southern portions of Mongolia, some workers have interpreted the Cretaceous Maanshan Uplift and associated Chifeng basins as metamorphic core complex. Previous work has relied solely upon kinematic indicators to determine the structural origin of these basins. To fully understand the creation of these basins, the sedimentiological record was analyzed in this study. The early Cretaceous sedimentary fill of these basins was analyzed to determine if it is synextensional in nature, and if so what manner of extension was in progress during that deposition.
The Chifeng basins are filled with …
Geochemical Provenance Of Clastic Sedimentary Rocks In The Western Cordillera: Utah, Colorado, Wyoming, And Oregon, John Aaron Peterson
Geochemical Provenance Of Clastic Sedimentary Rocks In The Western Cordillera: Utah, Colorado, Wyoming, And Oregon, John Aaron Peterson
All Graduate Theses and Dissertations, Spring 1920 to Summer 2023
Sedimentary rocks are an important source of information about previous orogenic conditions and the composition of which may describe the evolution of provenance and tectonic setting. Many factors influence sediment composition, namely, source rock composition, chemical weathering, climate, transport burial, and diagenesis. As the sediment composition changes through time, the geochemical characteristics of the sediment can be used to understand its geologic history.
The geochemical characteristics of clastic sedimentary rocks are useful in determining the depositional setting and its associated provenance. Although many different studies have used geochemical discriminants to evaluate provenance and tectonic settings, none have used a defined …
Fluvial Systems Tied Together Through A Common Base Level: The Geomorphic Response Of The Dirty Devil River, North Wash Creek, And The Colorado River To The Rapid Base Level Drop Of Lake Powell, Adam L. Majeski
All Graduate Theses and Dissertations, Spring 1920 to Summer 2023
Fluvial adjustment to base level change has its roots in the fundamental concepts of geomorphology. This thesis explores the rate of erosion and sedimentation on the Colorado and Dirty Devil rivers and North Wash Creek under the current base level changes related to the drawdown conditions of Lake Powell. Through cross section and long profile resurveys, the current state of each system is captured and added to the historic record of sedimentation in Lake Powell. All three systems are generally forming narrow and deep incised channels driven by the rapid rate of base level fall. Cross sections that deviate from …
Arkosic Rocks From The San Andreas Fault Observatory At Depth (Safod) Borehole, Central California: Implications For The Structure And Tectonics Of The San Andreas Fault Zone, S. D. Springer, James P. Evans, J. I. Garver, D. Kirschner, Susanne U. Janecke
Arkosic Rocks From The San Andreas Fault Observatory At Depth (Safod) Borehole, Central California: Implications For The Structure And Tectonics Of The San Andreas Fault Zone, S. D. Springer, James P. Evans, J. I. Garver, D. Kirschner, Susanne U. Janecke
Geosciences Faculty Publications
The San Andreas Fault Observatory at Depth (SAFOD) drill hole encountered indurated, high-seismic-velocity arkosic sedimentary rocks west of the active trace of the San Andreas fault in central California. The arkosic rocks are juxtaposed against granitic rocks of the Salinian block to the southwest and against fine-grained Great Valley Group and Jurassic Franciscan rocks to the northeast. We identify three distinct lithologic units using cuttings, core petrography, electrical resistivity image logs, zircon fission-track analyses, and borehole-based geophysical logs. The upper arkose occurs from 1920 to 2530 m measured depth (mmd) in the borehole and is composed of five structural blocks …
Pleistocene Reorganization Of The Southern San Andreas Fault System, A. N. Steely, Susanne U. Janecke, G. J. Axen, R. J. Dorsey
Pleistocene Reorganization Of The Southern San Andreas Fault System, A. N. Steely, Susanne U. Janecke, G. J. Axen, R. J. Dorsey
Geosciences Faculty Publications
Structural and stratigraphic analyses along the western margin of the Salton Trough show that the San Andreas fault system was reorganized in early Pleistocene time from a system dominated by two fault zones (the San Andreas fault and the West Salton detachment fault) to a network of dextral faults that include the San Andreas and at least four dextral faults to the southwest. The San Felipe fault zone, one of these dextral faults, has ~5.8 ± 2.8 km of right separation and consists of three principal faults in the Peninsular Ranges. These are the San Felipe fault in the WNW, …
Sedimentology, Stratigraphy, And Organic Geochemistry Of The Red Pine Shale, Uinta Mountains, Utah: A Prograding Deltaic System In A Mid-Neoproterozoic Interior Seaway, Caroline Amelia Myer
Sedimentology, Stratigraphy, And Organic Geochemistry Of The Red Pine Shale, Uinta Mountains, Utah: A Prograding Deltaic System In A Mid-Neoproterozoic Interior Seaway, Caroline Amelia Myer
All Graduate Theses and Dissertations, Spring 1920 to Summer 2023
The Red Pine Shale (RPS; ~1120m thick), uppermost formation of the Neoproterozoic Uinta Mountain Group, Utah, is an organic-rich sedimentary succession interpreted as a marine deltaic system that delivered immature sediment from the north that mixed with mature sediment from the east. Multiple data sets suggest regional climate and sea-level changes associated with changing organic-carbon burial rates.
Six facies were identified and represent wave-, tidal-, and river-influenced parts of the distal prodelta to delta front in a marine system. These include the shale facies and associated concretion facies (distal prodelta), the shale-sandstone facies (proximal prodelta to delta front), the slump …
Decadal-Scale Changes On Coral Reefs In Quintana Roo, Mexico, Thaddeus Allen Nicholls
Decadal-Scale Changes On Coral Reefs In Quintana Roo, Mexico, Thaddeus Allen Nicholls
All Graduate Theses and Dissertations, Spring 1920 to Summer 2023
In 1988 data on coral reef community composition were collected from two areas, Akumal and Chemuyil, Quintana Roo, Mexico, ranging from 5-35m depth. These areas were revisited in 2005 and data were collected by the same methods and at the same depths as in 1988. Data from 1988 and 2005 were compared to determine if the coral reefs had undergone significant changes, and what specific changes had occurred. Chi-square analysis determined that community composition data collected in 1988 are significantly different from data collected in 2005 at all sites and depths within the categories of corals, gorgonians, sponges, and macroalgae. …
Microtextural Constraints On The Interplay Between Fluidrockreactions And Deformation, Alexis K. Ault, Jane Selverstone
Microtextural Constraints On The Interplay Between Fluidrockreactions And Deformation, Alexis K. Ault, Jane Selverstone
Geosciences Faculty Publications
Schists from two mylonitic localities in the footwall of a low-angle normal fault in the eastern Alps record different degrees of embrittlement during exhumation, depending on the extent to which fluid–rock reactions proceeded. At one site, graphitic schists preserve textural evidence for two metamorphic reactions that modified XCO2XCO2 and/or fluid volume: (1) reaction between graphite and aqueous fluid that increased XCO2XCO2 without changing the molar amount of fluid, and (2) replacement of titanite by rutile, calcite, and quartz. The latter reaction involved net consumption of increasingly CO2-rich fluid. Areas where the first reaction proceeded are associated with abundant Mode I …
A Post-Project Assessment Of The Provo River Restoration Project: Channel Design, Reconfiguration, And The Re-Establishment Of Critical Physical Processes, Randy Ray Goetz
All Graduate Theses and Dissertations, Spring 1920 to Summer 2023
A physical assessment of the Provo River Restoration Project was undertaken in order to determine how alterations to the channel were designed, the nature of as-built channel morphology, and the performance of the reconfigured channel in terms of achieving frequent (2-year recurrence) bankfull discharge and increasing transient storage. Measures of channelized and reconfigured channel morphology were obtained using total station survey, digital aerial photography, and pebble counts. Results of geomorphic analysis were compared with similar measurements made by a regional consulting company, and stream channel design data, in order to determine that intended mitigation included reducing channel capacity, increasing sinuosity, …
Composition, Microstructures, And Petrophysics Of The Mozumi Fault, Japan: In Situ Analyses Of Fault Zone Properties And Structure In Sedimentary Rocks From Shallow Crustal Levels, Angela J. Isaacs, James P. Evans, Peter T. Kolesar, Tsuyoshi Nohara
Composition, Microstructures, And Petrophysics Of The Mozumi Fault, Japan: In Situ Analyses Of Fault Zone Properties And Structure In Sedimentary Rocks From Shallow Crustal Levels, Angela J. Isaacs, James P. Evans, Peter T. Kolesar, Tsuyoshi Nohara
Geosciences Faculty Publications
[1] We characterize the chemical, microstructural, and geophysical properties of fault-related rock samples from the 80–100 m wide Mozumi fault zone, north central Honshu, Japan. The fault is exposed in a research tunnel 300–400 m below the ground, and we combine geological data with borehole geophysical logs to determine the elastic and seismic properties of the fault zone. Detailed mapping within the tunnel reveals that the fault zone consists of two zones of breccia to foliated cataclasites 20 and 50 m thick. Two narrow (tens of centimeters wide) principal slip zones on which most of the slip occurred bound the …
A Faculty Workshop On Student Assessment, Iris M. Totten, Kirsten Nicolaysen, Sheryl Hodge, Mary S. Hubbard
A Faculty Workshop On Student Assessment, Iris M. Totten, Kirsten Nicolaysen, Sheryl Hodge, Mary S. Hubbard
Geosciences Faculty Publications
A faculty workshop was conducted that showcased assessment activities that could be incorporated into undergraduate and graduate geology courses. Fourteen different types of student assessment were presented. Workshop participants were asked to respond to questions about their familiarity and use of each type before and immediately following the workshop. In addition, they were asked to indicate how likely they would be to incorporate each type of assessment in their student grading practices in the future. Results suggest relatively high familiarity and use of the more traditional types of assessments (e.g., instructor- and commercially-produced pencil and paper exams, group projects, and …
Strike-Slip Fault Terminations At Seismogenic Depths: The Structure And Kinematics Of The Glacier Lakes Fault, Sierra Nevada United States, J. D. Kirkpatrick, Z. K. Shipton, James P. Evans, S. Micklethwaite, S. J. Lim, Peter R. Mckillop
Strike-Slip Fault Terminations At Seismogenic Depths: The Structure And Kinematics Of The Glacier Lakes Fault, Sierra Nevada United States, J. D. Kirkpatrick, Z. K. Shipton, James P. Evans, S. Micklethwaite, S. J. Lim, Peter R. Mckillop
Geosciences Faculty Publications
[1] Structural complexity is common at the terminations of earthquake surface ruptures; similar deformation may therefore be expected at the end zones of earthquake ruptures at depth. The 8.2 km long Glacier Lakes fault (GLF) in the Sierra Nevada is a left-lateral strike-slip fault with a maximum observed displacement of 125 m. Within the fault, pseudotachylytes crosscut cataclasites, showing that displacement on the GLF was accommodated at least partly by seismic slip. The western termination of the GLF is defined by a gradual decrease in the displacement on the main fault, accompanied by a 1.4 km wide zone of secondary …
Age And Structure Of The San Jacinto And San Felipe Fault Zones, And Their Lifetime Slip Rates, Susanne U. Janecke, R. J. Dorsey, B. Belgarde
Age And Structure Of The San Jacinto And San Felipe Fault Zones, And Their Lifetime Slip Rates, Susanne U. Janecke, R. J. Dorsey, B. Belgarde
Geosciences Faculty Publications
No abstract provided.
Early Pleistocene Initiation And Structural Complexities Of The San Jacinto And San Felipe Fault Zones, Western Salton Trough: Part Ii, Susanne U. Janecke, R. J. Dorsey, B. Belgarde
Early Pleistocene Initiation And Structural Complexities Of The San Jacinto And San Felipe Fault Zones, Western Salton Trough: Part Ii, Susanne U. Janecke, R. J. Dorsey, B. Belgarde
Geosciences Faculty Publications
No abstract provided.
Eocene To Oligocene Provenance And Drainage In Extensional Basins Of Southwest Montana And East-Central Idaho: Evidence From Detrital Zircon Populations In The Renova Formation And Equivalent Strata, C. N. Stroup, P. K. Link, Susanne U. Janecke, C. M. Fanning, G. M. Yaxley, L. P. Beranek
Eocene To Oligocene Provenance And Drainage In Extensional Basins Of Southwest Montana And East-Central Idaho: Evidence From Detrital Zircon Populations In The Renova Formation And Equivalent Strata, C. N. Stroup, P. K. Link, Susanne U. Janecke, C. M. Fanning, G. M. Yaxley, L. P. Beranek
Geosciences Faculty Publications
Middle Eocene to Early Miocene sedimentary rocks in southwest Montana and east-central Idaho were deposited within an actively extending north-trending rift system (Cabbage Patch beds and Medicine Lodge beds) and a broad depositional basin on the eastern flank of this rift (Renova Formation). Distinct sediment sources for sandstones from different parts of this extensional system are identified using detrital zircon SHRIMP geochronology and LA-MC-ICPMS Hf isotope geochemistry. Sedimentary petrology independently shows strong compositional similarities among sandstones grouped by provenance. The Muddy-Grasshopper detachment system was the eastern boundary of the Paleogene rift and controlled sediment dispersal patterns. Hf isotope ratios and …
The Geologic History Of Subsurface Arkosic Sedimentary Rocks In The San Andreas Fault Observatory At Depth (Safod) Borehole, Central California, Sarah D. Draper
The Geologic History Of Subsurface Arkosic Sedimentary Rocks In The San Andreas Fault Observatory At Depth (Safod) Borehole, Central California, Sarah D. Draper
All Graduate Theses and Dissertations, Spring 1920 to Summer 2023
The aim of the San Andreas Fault Observatory at Depth (SAFOD) project, a component of the NSF Earthscope Initiative, is to directly observe active fault processes at seismogenic depths through the drilling of a 3 km deep (true vertical depth) inclined borehole across San Andreas fault. Preliminary subsurface models based on surface mapping and geophysical data predicted different lithologies than were actually encountered. At 1920 meters measured depth (mmd), a sequence of well-indurated, interbedded arkosic conglomerates, sandstones, and siltstones was encountered. We present a detailed lithologic and structural characterization as a step toward understanding the complex geologic history of this …
Discharge Monitoring, Chemical Characterization, And Source Identification Of Springs Along The East Side Of Southern Cache Valley, Utah, Aric Alan Olsen
Discharge Monitoring, Chemical Characterization, And Source Identification Of Springs Along The East Side Of Southern Cache Valley, Utah, Aric Alan Olsen
All Graduate Theses and Dissertations, Spring 1920 to Summer 2023
Discharge monitoring and water sampling of springs in the southeastern portion of Cache Valley, Utah was performed in order to determine recharge sources and the cause of decreasing flows for some springs. The discharges of 43 springs were measured monthly from May or June of 2005 through March of 2006. Water samples from 36 of these springs plus an additional 10 were analyzed for major ions and trace metals. Twenty-one of the springs were analyzed for deuterium and oxygen-18 and 10 of these were analyzed for tritium.
The springs were divided into groups based on when they had their peak …