PETROLOGIC RELATIONSHIPS AND IN SITU U-Pb ZIRCON GEOCHRONOLOGY IN FELSIC ROCKS FROM THE WICHITA IGNEOUS PROVINCE, OKLAHOMA

For several decades, interpretations of the Wichita Igneous Province (WIP) of the Wichita Mountains of southwestern Oklahoma have been placed within the framework of the Southern Oklahoma Aulacogen, a hypothesized failed Cambrian rift. Many of these interpretations are based on near-indistinguishable Cambrian isotopic zircon U-Pb dates from igneous rocks within the WIP. In an attempt to challenge the current accepted model of an aulacogen, further geochronological constraint of the igneous suite is necessary. Here, we present high-precision U-Pb dates from zircons obtained during in situ EPMA thin section and/or rock analysis of felsic rocks in the WIP. By analyzing zircons in situ, we can obtain a better understanding of the spatio-temporal-chemical relationships in the igneous phases and, ultimately, better understand the processes that created this enigmatic geologic province.