Geology Commons^™

Structural Characterization Of Three Southeast Segments Of The Clark Fault, Salton Trough California, Benjamin E. Belgarde

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

We examine the structural complexities of a 28-km long part of the Clark fault of the San Jacinto fault zone in southern California in order to better document its lateral extent and the style of deformation of its southeast end. Changes in structural style are observed as the Clark fault’s damage zone widens from ~ 1-2 km in crystalline rocks of the Peninsular Ranges southeastward to ~ 18 km in the sedimentary rocks of the San Felipe-Borrego subbasin of the Salton Trough. The Clark fault extends into the San Felipe-Borrego subbasin as the Arroyo Salada segment for ~ 11-12 km …

Quaternary Evolution Of The Colorado River At Lees Ferry, Arizona, William Scott Cragun

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

A well-exposed suite of Colorado River fill terraces preserved at Lees Ferry records the oscillating history of this major river superimposed on its overall downcutting of the Colorado Plateau. Detailed mapping, sedimentology, cross-sectional surveys, and the use of two geochronometers have been used in order to establish a detailed chronostratigraphy for the area. Eight distinct deposits have been identified along the Colorado River (Ml -M7, and S3), and four deposits have been identified along the Paria River (Pl -P4).

Geochronology of six of these deposits using optically stimulated luminescence and cosmogenic ¹⁰Be exposure techniques indicates a long-term average bedrock …

Sequence Stratigraphy Of The Middle Cambrian Marjum Formation: Response Of Sedimentary Facies And Biota To Sea-Level Changes, Douglas D. Smith

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

Research on the Marjum Formation provides insight into facies transitions in the House Range embayment of southwestern Utah during the Middle Cambrian. Sections of the Marjum Formation and equivalents were measured in strata representing shallow- (Drum Mountains), intermediate- (Wheeler Amphitheater), and deep-ramp (Marjum Pass) environments. This traverse across the embayment reveals strong litho- and biofacies changes. The Drum Mountains strata (343 m thick) are dominated by thick-bedded shallow-water limestone facies containing polymerid trilobites and stromatolites. The Wheeler Amphitheater locality (392 m thick) provides an example of intermediate deposits between deep-water and shallow-water environments and is characterized by limestone and subordinate …

Effects Of Quaternary Climate Change On Tributary Sedimentation And Geomorphology In Eastern Grand Canyon, Benjamin D. Dejong

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

Climate variability has had a dramatic impact on eastern Grand Canyon tributaries over the past ~100 ky. This is readily observed in the Lava Chuar and Comanche catchments, which host well preserved colluvial remnants and river terraces that resulted from several climate-induced cycles of aggradation and incision. This study investigates these climate responses using surveying, sedimentology, and luminescence geochronology methods to investigate the mechanisms and timing of their deposition.

The survey data demonstrate that the concavity of terrace treads is lower than modern drainages. The sedimentology suggests the prevalence of stream-flow reworking of debris flow deposits and portrays an expected …

Does The Southern Farmington Canyon Complex Record A Late Archean/Early Proterozoic Accretionary Complex?, Kyle C. Andreasen

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

The Farmington Canyon Complex, situated along the Wasatch front in northern Utah, has been the target for many studies. The FCC has been interpreted to be a passive margin sedimentary wedge. Previous studies have yielded isotopic ages that broadly support an Archean age of formation, and a prominent mid-proterozoic amphibolite grade metamorphic event.

Based on this study, a new interpretation for the FCC is presented. Field relations and whole-rock geochemistry as well as recent advances in understanding Archean crustal processes have resulted in the FCC to be considered as an accretionary complex that formed along the SW margin of the …

Re-Evaluation Of The Jesse Ewing Canyon Formation: Implications For Neoproterozoic Paleogeography And Tectonic Setting Of Northeastern Utah, Andrew M. Brehm

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

Detailed analysis of the basal unit of the Uinta Mountain Group, the Jesse Ewing Canyon Formation, of northeastern Utah and northwestern Colorado, expands on previous work by further documenting the character of the unit and proposing a revision of the description of the formation and interpretation. The Jesse Ewing Canyon Formation is ~≤1,000 meters thick as opposed to ≤225 meters thick, and the dominant lithology is not conglomerate, but rather finer-grained facies. The Jesse Ewing Canyon Formation reveals multiple alluvial fan point sources feeding a shallow body of water in an active rift basin at ~781 Ma.

Stratigraphic mapping, measured …

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 …

Paleomagnetic Dating Of Fault Slip In The Southern Rocky Mountains, Usa, And Itsimportance To An Integrated Laramide Foreland Strain Field, T. F. Wawrzyniec, Alexis K. Ault, J. W. Geissman, E. A. Erslev, S. D. Fankhauser

Geosciences Faculty Publications

The Laramide orogen of the U.S. Cordillera formed in the latest Cretaceous, and deformation lasted into the earliest Oligocene. Along and proximal to the eastern and northern margins of the Colorado Plateau, deformation associated with this event mainly took place along reactivated structures. Related tectonic models invoke some role for the plateau either as a stress guide transmitting compression to the foreland or as a freely rotating microplate. Models dominated by northward displacements of the Colorado Plateau also require covariance between timing and magnitude of dextral strike-slip deformation in the eastern domain and thrust deformation in the northern domain. Here …

Cenozoic Extensional Processes And Tectonics In The Northern Rocky Mountains: Southwest Montana And Eastern Idaho, Susanne U. Janecke

Geosciences Faculty Publications

No abstract provided.

Pleistocene Brawley And Ocotillo Formations: Evidence For Initial Strike-Slip Deformation Along The San Felipe And San Jacinto Fault Zones, Southern California, S. M. Kirby, Susanne U. Janecke, R. J. Dorsey, B. A. Housen, K. Mcdougall, V. Langenheim, A. Steely

Geosciences Faculty Publications

We examine the Pleistocene tectonic reorganization of the Pacific–North American plate boundary in the Salton Trough of southern California with an integrated approach that includes basin analysis, magnetostratigraphy, and geologic mapping of upper Pliocene to Pleistocene sedimentary rocks in the San Felipe Hills. These deposits preserve the earliest sedimentary record of movement on the San Felipe and San Jacinto fault zones that replaced and deactivated the late Cenozoic West Salton detachment fault. Sandstone and mudstone of the Brawley Formation accumulated between ∼1.1 and ∼0.6–0.5 Ma in a delta on the margin of an arid Pleistocene lake, which received sediment from …

A Linear Modulation Osl Study Of The Unstable Ultrafast Component In Samples From Glacial Lake Hitchcock, Massachusetts, Usa, R. J. Goble, Tammy M. Rittenour

Geosciences Faculty Publications

Optical ages were determined for samples from delta and sand dune deposits associated with Glacial Lake Hitchcock near Amherst, Massachusetts using the single aliquot regenerative-dose (SAR) optically stimulated luminescence (OSL) technique. However, a strong unstable ultrafast component caused initial rejection of data from a large proportion of aliquots. A linearly modulated blue OSL (LM-OSL) study was undertaken on the sample with the strongest ultrafast component, with the data modelled using the equation of Bulur et al. (2000) as 5 fast, medium and slow components, and 1 ultrafast component.

The ultrafast component dominates the LM–OSL, almost completely obscuring the fast component. …

Lower Paleozoic Sequence Stratigraphy, Deposystems And Paleogeography Of Northwestern Ordos Basin, North China, Benjamin J. Kessel

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

The Ordos basin rests upon the North China Block and is one of the largest sedimentary basins in north China, with more than 15 km of Phanerozoic strata. Published estimates suggest that over 2000 m of carbonates and lesser amounts of siliciclastics were deposited on the North China Carbonate Platform (NCCP) from the Lower Can1brian through the Middle Ordovician. However, lower Paleozoic facies successions and deposystems of northwestern Ordos basin remain poorly represented in western literature. This paper constrains depositional environments, lithologies, facies relationships and sea-level history of the northwestern part of the North China block (NCB) in an effort …

The Evolution From Late Miocene West Salton Detachment Faulting To Cross-Cutting Pleistocene Oblique Strike-Slip Faults In The Sw Salton Trough, Southern California, Alexander N. Steely

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

Field studies in the southwest Salton Trough between Yaqui Ridge and Borrego Mountain show that the West Salton detachment fault was active during the Pliocene and may have initiated during the latest Miocene. At Yaqui Ridge dominantly east-directed extension is recorded by slickenlines on the NW-striking detachment fault, and shows that the fault is actually a low-angle dextral oblique strike-slip fault. Crustal inheritance is responsible for the position of the fault at Yaqui Ridge, which reactivates a late Cretaceous reverse-sense mylonite zone at map scale.

Late Miocene to Pliocene basin fill deposits at Borrego Mountain display progressive unconformities, contain detritus …

Using Fill Terraces To Understand Incision Rates And Evolution Of The Colorado River In Eastern Grand Canyon, Arizona, J. L. Pederson, M. D. Anders, Tammy M. Rittenour, W. D. Sharp, J. C. Gosse, K. E. Karlstrom

Geosciences Faculty Publications

The incision and aggradation of the Colorado River in eastern Grand Canyon through middle to late Quaternary time can be traced in detail using well-exposed fill terraces dated by a combination of optically stimulated luminescence, uranium series, and cosmogenic nuclide dating. This fluvial history provides the best bedrock incision rate for this important landscape and highlights the complications and advantages of fill terrace records for understanding river long-profile evolution and incision. The use of fill terraces, as distinct from strath terraces, for calculating incision rates is complicated by the cyclic alluviation and incision they record. In the example of the …

Multiple Phases Of Tertiary Extension And Synextensional Deposition Of The Miocene–Pliocene Salt Lake Formation In An Evolving Supradetachment Basin, Malad Range, Southeast Idaho, U.S.A., S. P. Long, P. K. Link, Susanne U. Janecke, D. W. Rodgers, M. E. Perkins, C. M. Fanning

Geosciences Faculty Publications

The extensional history of the Malad and Bannock ranges in southeast Idaho and northern Utah involves multiple phases of Tertiary normal faulting and synextensional deposition. Detailed geologic mapping, structural and stratigraphic analyses, and geochronologic data from this study elucidate previously defined deformational events in the region, and define two new extensional episodes.

The largest-magnitude extension took place along low-angle normal faults of the ∼10–4-Ma Bannock detachment system, with concurrent sedimentation of the Miocene–Pliocene Salt Lake Formation in a regionally continuous supradetachment basin. This basin developed by ∼10.2 Ma, and was preceded by two phases of smaller-magnitude, aerially restricted normal faulting …

Mineralogical Characterization Of Protolith And Fault Rocks From The Safod Main Hole, John G. Solum, Stephen H. Hickman, David A. Lockner, Diane E. Moore, Ben A. Van Der Pluijm, Anja M. Schleicher, James P. Evans

Geosciences Faculty Publications

Washed cuttings provide a continuous record of the rocks encountered during drilling of the main hole of the San Andreas Fault Observatory at Depth (SAFOD). Both protolith and fault rocks exhibit a wide variety of mineral assemblages that reflect variations in some combination of lithology, P-T conditions, deformation mechanisms, and fluid composition and abundance. Regions of distinct neomineralization bounded by faults may record alteration associated with fluid reservoirs confined by faults. In addition, both smectites occurring as mixed-layer phases and serpentine minerals are found in association with active strands of the San Andreas Fault that were intersected during drilling, although …

Structural Evolution And Vorticity Of Flow During Extrusion And Exhumation Of The Greater Himalayan Slab, Mount Everest Massif, Tibet/Nepal: Implications For Orogen-Scale Flow Partitioning, M. J. Jessup, R. D. Law, M. P. Searle, Mary S. Hubbard

Geosciences Faculty Publications

The Greater Himalayan Slab (GHS) is composed of a north-dipping anatectic core, bounded above by the South Tibetan detachment system (STDS_ and below by the Main Central thrust zone (MCTZ). Assuming simultaneous movement on the MCTZ and STDS, the GHS can be modelled as a southward-extruding wedge or channel. New insights into extrusion-related flow with the GHS emerge from detailed kinematic and vorticity analyses in the Everest region. At the highest structural levels, mean kinematic vorticity number (Wm) estimates of 0.74-0.91 (c. 45-28% pure shear) were obtained from sheared Tethyan limestone and marble from the Yellow Band on Mount Everest. …

The Quaternary Stratigraphy Of The Henrys Fork And Western Browns Park, Northeastern Uinta Mountains, Utah And Wyoming, Ronald C. Counts

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

The landscape evolution of the northeastern Uinta Mountains and the manner in which climatic and tectonic forcing have influenced it are not well constrained. Surficial deposits covering ~325 km² below the glacial termini in the Henrys Fork and ~50 km² along the Green River in western Browns Park were mapped at 1:24,000 scale to develop a Quaternary stratigraphic framework for the northeastern Uinta Mountains.

The Henrys Fork mapping area spans from late Wisconsinan moraines to Flaming Gorge Reservoir. The Henrys Fork stratigraphy contains 10 mainstem gravels, six piedmont gravels, and landslide deposits. Terraces preserved along the Henrys Fork …

Stratigraphic And Structural Analysis Of Coals In The Ferron Sandstone Member Of The Mancos Shale And Fruitland Formation: Relationship To Coal Reservoir Permeability And Coalbed Methane Production, Jason Lynn Kneedy

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

Coal reservoir quality in the Ferron Sandstone Member of the Mancos Shale, and in the Fruitland Formation is dependent on coal cleat characteristics. Coal reservoir permeability increases as a result of high cleat density. From careful outcrop examination, we were able to identify several factors that increase cleat density. Vitrain coal typically has the highest fracture density as a result of having well-developed face cleats and conchoidal fractures. Clarain coal contains face and butt cleats. Cleat density in clarain is also controlled by mechanical layer thickness. As mechanical layer thickness decreases, cleat density increases. Durain and fusain coals typically contain …

Characterizing Deformation, Damage Parameters, And Clay Composition In Fault Zones: Insights From The Chelungpu Thrust, Taiwan, And Mozumi Right Lateral Fault, Japan, Angela J. Isaacs

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

The Chelungpu thrust fault, Taiwan, and the Mozumi right-lateral fault, Japan, provide an opportunity to characterize active faults in clastic sedimentary rocks and provide constraints to seismologic models. The northern Chelungpu fault has a 10-30 m wide primary damage zone characterized by dense fractures and chemical alteration. The southern Chelungpu fault has a 25-70 m wide primary damage zone characterized by dense fractures, alteration, intensely sheared rock, and secondary faults. The complexity of the damage zone, geochemistry, and clay mineralogy of the southern fault zone reflects its greater maturity (~1 Ma) relative to the northern fault zone (~46-100 Ka). A …

Examination Of Exhumed Faults In The Western San Bernardino Mountains, California: Implications For Fault Growth And Earthquake Rupture, Joseph R. Jacobs

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

The late Miocene Cedar Springs fault system is a high-angle transpressional system in the Silverwood Lake area, western San Bernardino Mountains, southern California. This thesis presents the study of oblique-slip faults with modest amounts of slip, which represent the early stages of fault development by using slip as a proxy for maturity. A structural and geochemical characterization is provided for six fault zones ranging from 39 m of slip to 3.5 km of offset in order to develop a model of fault zone geometry and composition. Basic geometric and kinematic results are provided for an additional 29 small-displacement (cm- to …

The Quaternary Tectonic And Structural Evolution Of The San Felipe Hills, California, Stefan M. Kirby

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

We examine the transition between extension and strike-s lip in the San Felipe Hills, western Salton Trough, southern California using new and compiled geologic mapping, measured stratigraphic sections, magnetostratigraphy, and structural analysis. A 625 m measured section describes the Borrego, Ocotillo , and Brawley formations in the SE San Felipe Hills and constrains a regional disconformity and correlative angular unconformity at ~ 1 Ma. Sedimentation rates for the Brawley Formation above the disconformity range from 1.0 to 1.2 mm/yr, palcoflow was to the ENE. The Brawley Formation consists of three interbeddcd lithofac ics; (I) fluvial and fluvio-d eltaic, (2) lacustrinc, …

Relating Bedrock Strength To Hydraulic Driving Forces Along The Large-Scale Profile Of The Colorado River In Glen And Grand Canyons, Rob D. Mackley

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

The role of bedrock on the longitudinal profile of the Colorado River has intrigued workers for over a century. The river's profile exhibits large-scale (10 to 100 km) variations in geomorphology that are qualitatively associated with changes in rock type. This study provides the first bedrock-strength data to quantitatively test the relation of bedrock-resisting to hydraulic-driving forces in Glen and Grand canyons. The intent of this study is to explore the role, if any, that bedrock has on large-scale geomorphic variations along the profile of the Colorado River. Rock-strength data collected at 84 sites along the river corridor in Glen …

Seepage Study Of Mcleod Creek And East Canyon Creek Near Park City, Summit County, Utah, 2004, C. D. Wilkowske, U.S. Geological Survey, Snyderville Basin Water Reclamation District, U.S. Department Of The Interior

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

Seepage investigations on McLeod Creek downstream of U.S. Geological Survey streamflow-gaging station McLeod Creek near Park City, Utah, and its confluence with Kimball Creek during the summer of 2004 indicate that this section of the creek is a gaining reach. The total seepage gains ranged from 1.8 to 2.7 cubic feet per second, or a 32 to 55 percent gain. The apparent average total seepage gain was 2.2 cubic feet per second, or an average 42 percent gain. Seepage investigations from the U.S. Geological Survey streamflow-gaging station at East Canyon Creek below I-80 Rest Stop near Park City, Utah, to …

Field Guide To Exhumed Major Faults In Southern California, Joseph R. Jacobs, Samuel B. Howard, David Forand, Ory Dor, James P. Evans

Geosciences Faculty Publications

This field guide provides an overview of exposures and provides a field trip guide to localities of exhumed faults in southern California. We focus on exposures of faults that are documented or inferred to be exhumed from seismogenic depths. The goal of this guidebook is to provide geoscientists who are interested in fault zone mechanics and earthquake processes a summary of the results of the work on these sites.

Native Or Introduced? Fossil Pollen And Spores May Say. An Example From The Azores Islands, Jacqueline F.N. Van Leeuwen, Hanno Schäfer, W. O. Van Der Knapp, Tammy M. Rittenour, Svante Björck, Brigitta Ammann

Geosciences Faculty Publications

Aim: Among the various possible approaches to assess whether a species is native or introduced, the analysis of subfossil pollen and spores from natural archives is a valuable tool. Requirements include a sufficiently high taxonomic resolution of the pollen morphology, as well as sufficient temporal and spatial resolution. The aim of this study is to show the usefulness of this method in solving whether the taxon is native or introduced.

Location: The results are derived from two islands of the Azores: Flores and Pico. Methods: Analysis of pollen and spores in lake sediments; radiocarbon dating of the studied sediments.

Results: …

Evolution Of A Late Cenozoic Supradetachment Basin Above A Flat-On-Flat Detachment With A Folded Lateral Ramp, Se Idaho, A. N. Steely, Susanne U. Janecke, S. P. Long, S. C. Carney, R. Q. Oaks Jr., V. E. Langenheim, P. K. Link

Geosciences Faculty Publications

Uplift and exposure of the Bannock detachment system and the synextensional basin fill deposits of the Salt Lake Formation provide a unique exposure of the three-dimensional geometries of a low-angle normal fault system and the stratal architecture of the overlying supradetachment basin. Within this system, structural and stratigraphic analyses, outcrop patterns, tephra geochronology, and geological cross sections document several important relationships: (1) the Bannock detachment system developed above the Sevierage Cache-Pocatello culmination and resembles the Sevier Desert detachment in its geometry, structural setting, and kinematic evolution; (2) the Bannock detachment system initiated and slipped at low angles; (3) flat-on-flat, ramp-flat, …

Geologic Map Of The Bachelor Mountain 7.5' Quadrangle Beaverhead County, Montana, Susanne U. Janecke, R. J. Dorsey, J. C. Kickham, J. P. Matoush, W. Mcintosh

Geosciences Faculty Publications

Geologic Map of the Bachelor Mountain 7.5’ Quadrangle Beaverhead County, Montana Geologic Summary The Bachelor Mountain quadrangle is located in the Horse Prairie Creek drainage basin of southwest Montana and contains exposures of Middle Proterozoic metasedimentary rocks and eighteen map units of Eocene to Oligocene basin-fill deposits assigned to the Medicine Lodge beds. Locally, overlying upper Oligocene to lower Miocene(?) Everson Creek beds and late early to early late Miocene Bannack Pass beds are also preserved as basin-fill deposits. The Medicine Lodge beds were deposited in an early basin, the Grant protobasin (Fig. 1a), during slip on the Muddy-Grasshopper detachment …

Hydraulic Testing Of The Big Hole Fault, Northern San Rafael Swell, Utah, William M. Schieb

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

Six cross-hole packer tests were conducted at the Big Hole fault, a dip-slip normal fault in the northern San Rafael Swell of east-central Utah. Three tests were conducted at each of two locations along the fault, each location having a different total displacement. Water was injected in the footwall, hanging wall, and fault core and pressure changes were monitored in isolated intervals in the adjoining wells. Response curves were analyzed using the type curves developed by Hsieh and Neuman, and Theis, in order to evaluate the hydraulic properties of the fault and its associated damage zone.

The tests were not …

Geochemistry Of Ground Water - Surface Water Interactions And Metals Loading Rates In The North Fork Of The American Fork River, Utah, From An Abandoned Silver/Lead Mine, Neil I. Burk

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

The aqueous geochemistry and hydrology of the North Fork of the American Fork River, its tributaries, and the ground water in the vicinity of the Pacific Mine site were investigated in order to determine what impact ground water entering the North Fork has on toxic metal loads in the river. Toxic metal contamination in the North Fork is great enough that brown and cutthroat trout have absorbed lead, cadmium, and arsenic in their tissues at concentrations that are hazardous to human health if consumed. Ground water that flows through the mine site flows directly through the mine tailings before entering …