Date of Graduation
Eberly College of Arts and Sciences
Geology and Geography
Amy L Weislogel
By integrating high-precision, U-Pb zircon geochronology with zircon and whole rock/ tuff geochemistry, the tectonic history of an active margin can be assessed independently from strata preserved in sedimentary basins. This approach is particularly useful in regions where subsequent active tectonism has resulted in extensive igneous intrusion, tectonic dissection, or structural deformation of crustal suites, obscuring the record of previous geologic events. In this work I present 603 U-Pb zircon age coupled with zircon geochemical analyses collected from Sensitive High Resolution Ion Microprobe (SHRIMP) microanalyses, 15 U-Pb zircon Thermal Ionization Mass Spectrometry (TIMS) ages, and 109 U-Pb Laser Ablation-Inductively Coupled Plasma Mass Spectrometer (LA-ICPMS), and 41 whole rock geochemical analyses to assess 1) the utility and limitations of U-Pb zircon tuff geochronology when estimating absolute depositional ages of strata for chronostratigraphy, 2) the petrogenesis of volcanic tuffs from zircon U-Pb age and rare earth element (REE) compositions, and whole rock major and trace element concentrations, 3) advantages and limitations of geochronologic techniques (TIMS vs. SHRIMP vs. LAICPMS) and 4) the interaction between plate margin magmatism, orogenic deformation, and sedimentation into a tectonically active basin.
McKay, Matthew P., "Integrated geochronology and petrogenesis of volcanic suites for tectonic sedimentary studies: Karoo Basin, South Africa" (2015). Graduate Theses, Dissertations, and Problem Reports. 6200.