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Full-Text Articles in Physical Sciences and Mathematics

Characterizing Crystal Populations For The Petrogenesis Of The Post-Collapse Rhyolites In The Long Valley Caldera, California, William Joseph Dec 2016

Characterizing Crystal Populations For The Petrogenesis Of The Post-Collapse Rhyolites In The Long Valley Caldera, California, William Joseph

UNLV Theses, Dissertations, Professional Papers, and Capstones

Post-collapse rhyolites of the Long Valley in eastern California are the product of remelting of crystal mush bodies via mafic rejuvenation following the eruption of the Bishop Tuff. This is supported by mineral textures and major element geochemistry from the Resurgent Dome rhyolite, the Moat rhyolite, the Hot Creek Flow, and the Deer Mountain rhyolite. New 40Ar/39Ar eruptive ages are reported for the Moat rhyolites (525 ka, 333 ka, 118 – 94 ka), Hot Creek Flow (312 – 295 ka), and the Deer Mountain rhyolite (65 ka). The initial post-collapse eruptions, resulting in the Resurgent Dome rhyolite, appear to be …


Assessing A Potential Paleothermal Anomaly Near A Salt Wall Using (U-Th)/He Thermochronology And Silica Cementation Analysis, Onion Creek, Utah, Richard Gregory Ness Dec 2016

Assessing A Potential Paleothermal Anomaly Near A Salt Wall Using (U-Th)/He Thermochronology And Silica Cementation Analysis, Onion Creek, Utah, Richard Gregory Ness

UNLV Theses, Dissertations, Professional Papers, and Capstones

The Onion Creek salt wall in Fisher Valley, Utah is an exposed salt structure that lies adjacent to sandstones of the Permian age Cutler Group. The thermal conductivity of salt is two to four times greater than other sedimentary rocks and has been shown to act as a regional conduit for heat flow which has implications for petroleum systems in hydrocarbon exploration. Numerical models predict that thermal anomalies should extend 1.5 times the radius of a salt structure into adjacent strata. I hypothesized that an elevated paleothermal anomaly exists in sandstones of the Cutler Group where they are located near …


Canovas Canyon Rhyolites, Jemez Volcanic Field, New Mexico: Discrete Source Magmas, Or A Potential Caldera Forming Magma System?, Penelope Marie Padmore Dec 2016

Canovas Canyon Rhyolites, Jemez Volcanic Field, New Mexico: Discrete Source Magmas, Or A Potential Caldera Forming Magma System?, Penelope Marie Padmore

UNLV Theses, Dissertations, Professional Papers, and Capstones

The Jemez volcanic field (JVF), New Mexico, is a caldera-forming volcanic field located at the junction of the Rio Grande Rift and the Jemez Lineament. The JVF is one of three large North American caldera-forming systems, including Long Valley, California and Yellowstone Plateau volcanic field, Wyoming, which have been active during the Quaternary. Because portions of the JVF are unusually well preserved, it offers a rare opportunity to study how such systems develop. Insight into the history of caldera-forming systems will contribute to the understanding of their potential future behavior. In the case of Yellowstone and Long Valley, that insight …


Structural Evolution Of The Maynard Lake Fault Within The Left-Lateral Pahranagat Shear Zone, Nevada, Usa, Mahmud Mustafa Muhammad Aug 2016

Structural Evolution Of The Maynard Lake Fault Within The Left-Lateral Pahranagat Shear Zone, Nevada, Usa, Mahmud Mustafa Muhammad

UNLV Theses, Dissertations, Professional Papers, and Capstones

The Pahranagat shear zone (PSZ) contains three ENE-striking left-lateral strike-slip faults: The Arrowhead Mine fault (AMF), Buckhorn fault (BF), and Maynard Lake fault (MLF) from north to south. This shear zone lies along the boundary between the northern and central Basin and Range physiographic sub-provinces (NBR-CBR). In addition, this zone is positioned SW of a regional strike-slip zone, the Caliente-Enterprise zone (CEZ), and surrounded by extensional domains with differences in timing and magnitude of extension. Hence, understanding the development of the PSZ, particularly the MLF, is essential to better understanding tectonic evolution of the boundary zone between the northern and …


Patterns Of Synorogenic Sedimentation Associated With The Unroofing Of The Willard-Paris-Meade Thrust Sheets, Sevier Fold-Thrust Belt, Amanda Gentry Aug 2016

Patterns Of Synorogenic Sedimentation Associated With The Unroofing Of The Willard-Paris-Meade Thrust Sheets, Sevier Fold-Thrust Belt, Amanda Gentry

UNLV Theses, Dissertations, Professional Papers, and Capstones

The Willard-Paris-Meade thrust is the oldest and western-most sheet to develop in the Wyoming salient of the Sevier fold-thrust belt. The 10-15 km thick thrust sheet was emplaced ~60 km eastward and included Jurassic-Triassic strata, mixed siliciclastic-carbonate upper Paleozoic strata, carbonate-rich lower Paleozoic strata, and quartzite-rich basal Cambrian to Neoproterozoic strata. Each stratigraphic interval has a distinctive detrital zircon (DZ) age signature, which can be used in provenance analysis of foreland basin fill. The thrust system had a long deformation history recorded by westward thickening and coarsening synorogenic strata. DZ U-Pb geochronology of 27 synorogenic samples collected from two transects …


Characterizing The Earliest Stages Of Partial Melting: A Study Of The Pyrometamorphic Aureole Of Miocene Mt. Perkins Pluton, Northwest Arizona, Mathew Beshears May 2016

Characterizing The Earliest Stages Of Partial Melting: A Study Of The Pyrometamorphic Aureole Of Miocene Mt. Perkins Pluton, Northwest Arizona, Mathew Beshears

UNLV Theses, Dissertations, Professional Papers, and Capstones

Partial melting is an important process in the evolution of continental crust. Due to its progressive nature, evidence of the early stages of partial melting is often overprinted by later, advanced stages of partial melting. Experimental work has provided a model for the early stages of partial melting, but is limited to timescales of hours to weeks. Pyrometamorphic environments within the contact aureole of mafic intrusions provide natural laboratories for the study of the earliest stages of partial melt production on geologic time scales of 102 collected along two traverses of the tilted pyrometamorphic aureole of the Mt. Perkins pluton …


(U-Th)/He Studies Of The Southern Snake Range Metamorphic Core Complex, Nv And Gypsum Valley Salt Wall, Paradox Basin, Co, Usa, Sarah Lynn Evans May 2016

(U-Th)/He Studies Of The Southern Snake Range Metamorphic Core Complex, Nv And Gypsum Valley Salt Wall, Paradox Basin, Co, Usa, Sarah Lynn Evans

UNLV Theses, Dissertations, Professional Papers, and Capstones

This dissertation presents three studies that investigate extension in the Southern Snake Range (SSR) metamorphic core complex (MCC) of east-central Nevada and a thermal anomaly associated with the Gypsum Valley salt wall (GVSW) of southwestern Colorado. Low temperature thermochronologic studies using the (U-Th)/He system have been applied in numerous geologic settings to understand erosional and tectonic denudation processes. Two of the studies presented use (U-Th)/He thermochronology, combined with other techniques, to investigate the extensional history of the SSR and the extent of the GVSW thermal anomaly. Both of these studies present novel methods for understanding the thermal histories of the …