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U-Pb and Hf detrital zircon geochronology and provenance of the Missourian Cottage Grove Sandstone, northern Anadarko Basin, Oklahoma

Morton, Dylan M.
The Late Pennsylvanian Cottage Grove Sandstone in the northern Anadarko Basin of northwest Oklahoma is characterized as a series of shallow marine shoals that display reservoir heterogeneity largely driven by detrital composition and diagenetic alteration. Porosity within the formation is mostly secondary due to the dissolution of carbonate cements, detrital matrix, and labile grains such as abundant schistose metamorphic rock fragments and less abundant, occasional plutonic rock fragments that are observed by petrographic analysis and that are both of unknown origin. Depositional settings for the Cottage Grove Sandstone transition from shallow marine deposits in northwest Oklahoma to fluvial-deltaic deposits in central Oklahoma suggesting sediment dispersal from the east-southeast. Petrology of the Cottage Grove Sandstone suggests a complex assemblage of source terranes that host sedimentary, metamorphic, and minor contributions of plutonic, igneous rocks.
This study presents 288 new detrital zircon U-Pb ages and 26 new εHf(t) measurements for the Cottage Grove Sandstone with a goal of identifying sedimentary provenance. Overall, U-Pb ages are characterized by 44% Grenville (950-1,250 Ma), 16% Midcontinent Granite-Rhyolite (1,300-1,550 Ma), 10% Appalachian synorogenies (290-500 Ma), 9% peri-Gondwanan (500-800 Ma), 7% Yavapai-Mazatzal (1,600-1,800 Ma), 6% Superior (>2,500 Ma), 1% Penokean (1,800-2,000 Ma), and <1% Wichita (530-540 Ma) sourced zircons. U-Pb signatures compared between the Cottage Grove and previous studies suggest that sediment sourcing occurred from terranes to the north and east-northeast. Geochronologic data also suggest possible connections between source terranes, sedimentary basins, and associated dispersal systems, such as fluvial routing systems that are thought to have flowed from the northern Laurentian craton and the east-northeast Appalachian orogen to subsiding basins of the Midcontinent during the Late Mississippian to Late Pennsylvanian. εHf(t)-U-Pb signatures support that 290-500 Ma aged zircons were sourced from the Appalachian synorogenies. εHf(t)-U-Pb signatures and petrographic evidence support that 500-800 Ma aged zircons were sourced from the Ganderia and Avalonia peri-Gondwanan terranes of the northern Appalachians. Sediments sourced directly to the Anadarko Basin likely entered the Oklahoma region from the north, northeast, and/or east. Recycled sediments contributed from the Ouachita Mountains were likely restricted to the more mature, resistant grains such as quartz and associated zircons.