Earth and Planetary Sciences ETDs

Publication Date

Spring 5-8-2008

Abstract

The origin and evolution of continental crust is a fundamental and debated topic in geoscience. For over thirty years, Proterozoic crust of the southwestern United States has been a field laboratory for studying orogenic processes in the middle crust, and the growth of continental lithosphere via accretionary orogenesis. Three distinct crustal provinces are delineated based on differences in isotopic, structural, and geochronologic characteristics. To address questions about the origin of each province, this dissertation is composed of three chapters that present new U-Pb and Lu-Hf isotope analysis of plutonic, volcanic, and detrital zircon from the oldest known rocks in each crustal province in order to better understand the processes responsible for initial lithospheric formation and subsequent modification. Collectively, these chapters present a new synthesis of lithospheric formation during successive accretionary orogenic episodes that builds on three decades of prior field-based structural, metamorphic, and geochronologic studies. Major conclusions of each chapter are summarized in an extended abstract in the main body of this dissertation.

Degree Name

Earth and Planetary Sciences

Level of Degree

Doctoral

Department Name

Department of Earth and Planetary Sciences

First Committee Member (Chair)

Karl E Karlstrom

Second Committee Member

Matthew Heizler

Third Committee Member

Laura Crossey

Fourth Committee Member

Brandon Schmandt

Language

English

Document Type

Dissertation

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