Date of Graduation

2015

Document Type

Dissertation

Degree Type

PhD

College

Eberly College of Arts and Sciences

Department

Geology and Geography

Committee Chair

Amy L Weislogel

Committee Co-Chair

Kathleen Benison

Committee Member

Andrea Fildani

Committee Member

Thomas Kammer

Committee Member

Jaime Toro

Abstract

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.

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