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Full-Text Articles in Physical Sciences and Mathematics
Syn- To Post-Orogenic Evolution Of Collisional Mountain Systems: Investigating The Potential For Crustal Flow Using Thermochronology And Numerical Models, Brandon Spencer
Syn- To Post-Orogenic Evolution Of Collisional Mountain Systems: Investigating The Potential For Crustal Flow Using Thermochronology And Numerical Models, Brandon Spencer
Theses and Dissertations--Earth and Environmental Sciences
This dissertation is composed of three distinct manuscripts which collectively investigate processes that contribute to the late evolution of collisional mountain systems —specifically, the ancient Appalachian-Caledonian system. In the first paper, 40Ar/39Ar thermochronological data are used to constrain the timing of exhumation of the Scandian orogenic wedge of northern Scotland. Muscovite and amphibole samples yield dates of ca. 420-411 Ma, consistent with cooling after peak orogenesis. During this cooling phase, dates from both systems in individual thrust sheets show an increase in cooling rate in the later stage of exhumation; in the orogenic core, the cooling rate …
Testing Interpretations Of The Displacement Magnitude Of The Teton Fault And Uplift Of The Teton Range, Wyoming With Integrated Flexural-Kinematic And Thermal Modeling, Autumn Helfrich
Theses and Dissertations--Earth and Environmental Sciences
The Teton fault is a range-front normal fault in northwestern Wyoming. Previous estimates of the maximum displacement (Dmax) on the Teton fault cover a wide range (2 - 11 km). Discrepancies also exist regarding the slip onset timing, which spans 2 - 13 Ma. To address these discrepancies, the exhumation history of the Teton Range is here investigated using forward flexural-kinematic (Move) and thermal-kinematic (Pecube) models that can be compared with previously reported apatite fission track (AFT) and apatite (U-Th)/He (AHe) ages from Mount Moran, which has been previously hypothesized to represent the …
Determining Rates Of Landscape Response To Tectonic Forcing Across A Range Of Temporal Scales And Erosional Mechanisms: Teton Range, Wy, Meredith Swallom
Determining Rates Of Landscape Response To Tectonic Forcing Across A Range Of Temporal Scales And Erosional Mechanisms: Teton Range, Wy, Meredith Swallom
Theses and Dissertations--Earth and Environmental Sciences
Understanding how mountain landscapes respond to variations in tectonic forcing over a range of temporal scales in active mountain belts remains as a prominent challenge in tectonic and geomorphological studies. Although a number of empirical and numerical studies have examined this problem, many of them were complicated by issues of scale and climatic variability. More specifically, the relative efficiencies of fluvial and glacial erosion, which are presumably controlled by climate, are difficult to unravel. The Teton Range in Wyoming, which results from motion on the crustal-scale Teton fault, is an ideal natural laboratory for addressing this challenge as the tectonic …
Zircon U-Pb Geochronology Of Two Basement Cores (Kentucky, Usa): Implications For Late Mesoproterozoic Sedimentation And Tectonics In The Eastern Midcontinent, David P. Moecher, J. Richard Bowersox, John B. Hickman
Zircon U-Pb Geochronology Of Two Basement Cores (Kentucky, Usa): Implications For Late Mesoproterozoic Sedimentation And Tectonics In The Eastern Midcontinent, David P. Moecher, J. Richard Bowersox, John B. Hickman
Earth and Environmental Sciences Faculty Publications
Basement cores from two wells drilled west and east of the Grenville front consist of feldspathic litharenite and granitic orthogneiss, respectively. Detrital zircon U-Pb ages for the litharenite define a broad dominant U-Pb age mode at ca. 1115 Ma. The dominant mode matches that for the type locality of the Middle Run Formation in the Ohio subsurface and is interpreted to consist of detrital zircons sourced from East Continent Rift volcanic sources (ca. 1100 Ma) and Grenville Shawinigan granites/gneisses (1120–1180 Ma). The youngest detrital zircon ages (ca. 1020 Ma) require a maximum depositional age that is at least 70 My …
Petrologic, Geochemical, And Geochronologic Constraints On The Tectonic Evolution Of The Southern Appalachian Orogen, Blue Ridge Province Of Western North Carolina, Eric Douglas Anderson
Petrologic, Geochemical, And Geochronologic Constraints On The Tectonic Evolution Of The Southern Appalachian Orogen, Blue Ridge Province Of Western North Carolina, Eric Douglas Anderson
University of Kentucky Doctoral Dissertations
The Blue Ridge Province of western North Carolina contains a wide variety of metamorphosed igneous and sedimentary rocks that record the tectonic effects of Precambrian and Paleozoic orogenic cycles. Tectonic interpretations of the events that led to the present configuration are varied and often conflicting. This investigation examines metamorphosed mafic rocks that are widely interpreted to have formed during the closure of ocean basins. Metabasites, and specifically eclogites, have a tendency to mark tectonic sutures and frequently preserve pressure (P), temperature (T), and age data (t) that can be gleaned from mineral equilibria and U-Pb isotopic compositions. As such, the …