Physical Sciences and Mathematics Commons^™

Garnet Dating, Pressure-Temperature Time Paths And Kinematic Analysis Of The Schist Of Upper Narrows, Raft River Mountains, Northwestern Utah: Tectonic Implications Of Pressure-Temperature-Time-Deformation Paths, Alison Christine Lacy

UNLV Theses, Dissertations, Professional Papers, and Capstones

The hinterland of the Sevier orogenic belt underwent multiple episodes of synconvergent extension, prior to a brief transitional phase from shortening to overall extension that affected the entire orogen during the Early Eocene. The timing of the final transition from contraction to extension, while well documented in the Sevier fold-thrust belt, remains poorly constrained within the hinterland. The study of metamorphic rocks within the hinterland region provides a unique perspective on the nature of deformational events as well as the timing of the transition from contractional to extensional processes. Garnets from the schist of Upper Narrows in the western Raft …

Application Of (U-Th)/He And 40ar/39ar Thermochronology To The Age Of Thrust Faulting In The Sevier Orogenic Belt, Michael Giallorenzo

UNLV Theses, Dissertations, Professional Papers, and Capstones

The Sevier fold-thrust belt of the Cordilleran orogen in the western United States is a well-studied geologic province, yet our understanding of the history of thrust faulting is still far from complete. Thermochronological methods are applied to major thrust systems from two distinct sections of the Sevier fold-thrust belt (SFTB): the Wheeler Pass thrust in the Mojave Desert section of the southern SFTB, and the Willard thrust in the Idaho-Utah-Wyoming section of the SFTB. The new thermochronological data greatly improve our understanding of the structural evolution of this extensive geologic province.

The zircon (U-Th)/He (ZHe) system records thrust-induced uplift and …

Kinematics And Timing Of Orogen-Parallel Flow, Grouse Creek Mountains, Utah, Tonia Gail Arriola

UNLV Theses, Dissertations, Professional Papers, and Capstones

Alternating contractional and extensional events in orogenic belts play a significant role in dynamically adjusting crustal thickness during regional contraction. Distinguishing between these two contrasting kinematic regimes is not only important for understanding the tectonic setting but also provides insights into the dynamics of evolving orogenic wedges. The earliest pervasive fabric, D ₁ , in the Grouse Creek Mountains of northwest Utah is interpreted to have played an integral role in accommodating such a dynamic adjustment. It is interpreted that focused crustal thickening led to differences in gravitational potential energy along strike, facilitating an episode of mid-Cretaceous synconvergent orogen-parallel extension. …