DETRITAL ZIRCON U-PB GEOCHRONOLOGY OF UPPER MISSISSIPPIAN SILTSTONE OF THE ANADARKO BASIN

The origin of the silt in the Meramec STACK reservoirs of the Anadarko Basin and age equivalent units is not well understood, despite economic importance as an unconventional petroleum reservoir. Recently published models have invoked various sediment transport mechanisms, which are highly debated. It is argued that the Upper Mississippian silt was largely sourced from the Appalachian highland to the east and transported via rivers which were influenced by coastal currents and trade winds. Conversely, alternative hypotheses suggest transcontinental sediment dispersal pathways via contour-parallel currents and gravity flows. Detrital zircon (DZ) U-Pb geochronology, siltstone petrography, and portable x-ray fluorescence (pXRF) will be used to constrain sediment provenance and primary sediment dispersal pathways of Upper Mississippian (Meramecian and Chesterian) strata in the Anadarko and Ardmore Basin, and in the surrounding regions within the North American Craton. This study implements a successful new mineral separation technique specific for processing silt-sized material, a new method for imaging silt-sized detrital zircon grains, and an emerging method for predicting zircon recovery utilizing pXRF elemental geochemistry. U-Pb dating is being conducted on 18 samples to identify the crystallization age of the detrital zircons which comprise the Upper Mississippian silt-size fraction. Petrographic thin sections are being point counted to improve the characterization of the unconventional reservoirs and better understand the depositional history. This research aims to characterize the sedimentary provenance of Upper Mississippian siltstone, including equivalents of the Meramecian-aged STACK play of the Anadarko Basin, and to improve understanding of transcontinental sediment dispersal pathways.