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Full-Text Articles in Physical Sciences and Mathematics
Natural And Experimental Slow Slip Observed Along Shallow Hematite Faults, Alexandra A. Dimonte
Natural And Experimental Slow Slip Observed Along Shallow Hematite Faults, Alexandra A. Dimonte
All Graduate Theses and Dissertations, Spring 1920 to Summer 2023
Fault slip relieves stress in the shallow crust by slipping suddenly during earthquakes, but some faults also slip slowly in between earthquakes. Exhumed faults, brought up to the Earth’s surface from depth, preserve a record of fault processes and slip rates informed by fault rock structures, textures, and chemistry. Hematite, a common iron oxide mineral that precipitates on fault surfaces, exhibits crystal textures that potentially indicate past slip rate. Hematite can be dated using the radioisotopic system of (U-Th)/He thermochronometry, which constrains the time when He is trapped within a crystal, a process that is a function of temperature. Exhumed …
Hematite (U-Th)/He Thermochronometry Detects Asperity Flash Heating During Laboratory Earthquakes, Melissa S. Chapot, Alexis K. Ault, Greg Hirth, Robert G. Mcdermott
Hematite (U-Th)/He Thermochronometry Detects Asperity Flash Heating During Laboratory Earthquakes, Melissa S. Chapot, Alexis K. Ault, Greg Hirth, Robert G. Mcdermott
Geosciences Faculty Publications
Evidence for coseismic temperature rise that induces dynamic weakening is challenging to directly observe and quantify in natural and experimental fault rocks. Hematite (U-Th)/He (hematite He) thermochronometry may serve as a fault-slip thermometer, sensitive to transient high temperatures associated with earthquakes. We test this hypothesis with hematite deformation experiments at seismic slip rates, using a rotary-shear geometry with an annular ring of silicon carbide (SiC) sliding against a specular hematite slab. Hematite is characterized before and after sliding via textural and hematite He analyses to quantify He loss over variable experimental conditions. Experiments yield slip surfaces localized in an ∼5–30-µm-thick …
Analysis Of Small Faults In A Sandstone Reservoir Analog, San Rafael Desert: Implications For Fluid Flow At The Reservoir-Scale, Leslie Noël Clayton
Analysis Of Small Faults In A Sandstone Reservoir Analog, San Rafael Desert: Implications For Fluid Flow At The Reservoir-Scale, Leslie Noël Clayton
All Graduate Theses and Dissertations, Spring 1920 to Summer 2023
We examined small-displacement faults in the Jurassic Entrada Sandstone adjacent to the Iron Wash Fault, central Utah east of the San Rafael Swell, in order to describe the nature and timing of past fluid movement and deformation in the Entrada Sandstone. Using field studies, microscopy, and X-ray diffraction analysis, we identified mineralized fractures and cementation features in association with deformation bands and fractures at the interface of the Earthy and Slick Rock Members of the Entrada Sandstone.
Where the faults cross the Earthy-Slick Rock Member interface, deformation band faults in the Slick Rock Member become opening-mode fractures in the Earthy …
Fault And Fluid Interactions In The Elsinore Fault-West Salton Detachment Fault Damage Zones, Agua Caliente County Park, California, Rebekah Erin Wood
Fault And Fluid Interactions In The Elsinore Fault-West Salton Detachment Fault Damage Zones, Agua Caliente County Park, California, Rebekah Erin Wood
All Graduate Theses and Dissertations, Spring 1920 to Summer 2023
This study area provides a unique opportunity to study the intersection of the Elsinore and West Salton detachment faults in southern California, effusing warm springs, and alteration products in the midst of the fault intersection. Structural mapping and compiling previous maps supply an interpretation of the fault zone geometries within the Tierra Blanca Mountains. Geochemical analysis of the crystalline basement and altered protolith help determine the effects of faulting and fluid flow in the study area. In the Tierra Blanca Mountains, the Elsinore strike-slip fault system transitions from the double-stranded Julian segment and Earthquake Valley fault in the northwest, to …
Drilling Active Tectonics And Magmatism (Volcanics, Geoprisms, Fault Zones Post-Safod) Proceedings Of A Workshop, John W. Shervais, James P. Evans, Virginia Toy, John Eichelberger, James Kirkpatrick, Amanda Clarke
Drilling Active Tectonics And Magmatism (Volcanics, Geoprisms, Fault Zones Post-Safod) Proceedings Of A Workshop, John W. Shervais, James P. Evans, Virginia Toy, John Eichelberger, James Kirkpatrick, Amanda Clarke
Geosciences Faculty Publications
No abstract provided.
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
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 …
Structural Geology Of Eastern Part Of The Malad Summit Quadrangle, Idaho, Jay Nevin Shearer
Structural Geology Of Eastern Part Of The Malad Summit Quadrangle, Idaho, Jay Nevin Shearer
All Graduate Theses and Dissertations, Spring 1920 to Summer 2023
The mapped area represents the eastern three-fourths of the Malad Summit Quadrangle, Idaho. It lies mainly in the Bannock Range of southeastern Idaho. The northern and southern margins of the area are 25.5 miles and 17.0 miles, respectively, north of the Idaho-Utah State Line.
The Caddy Canyon Formation of Late Precambrian age is the oldest exposed stratigraphic unit. The youngest unit, exclusively of Precambrian age, is the Mutual Formation. The Brigham Formation is considered to be of Late Precambrian to Early Cambrian(?) age. Younger formations of Cambrian to Silurian age are present. The Precambrian units, as well as the Brigham, …