DETRITAL ZIRCON SIGNATURES OF PALEOZOIC SUCCESSIONS IN SOUTHERN OZARK DOME: IMPLICATIONS OF TECTONICS AND SEDIMENT DISPERSAL IN SOUTHERN MIDCONTINENT

Southern midcontinent region experienced multiple eustatic cycles of transgression and regression from the Late Cambrian through the Late Mississippian. Consequently, Paleozoic sedimentation in southern midcontinent of the North America transit gradually from dominantly carbonate rich succession to a more clastic rich succession. A transcontinental sediment dispersal model has been proposed to link sources from partly re-emergence Canadian Shield and onset of the Appalachian orogenic belt from east-northeast and south. In this study, we present results of U-Pb detrital zircon geochronology from a series of Paleozoic sandstones from northern Arkansas and southern Missouri. Results show that the siliciclastic strata include virtually all major basement provenances of North American craton, and its age distributions can be subdivided into six groups: ~350-500, ~900-1350, ~1360-1500, ~1600-1800, ~1800-2300, and > ~2500 Ma. Regional correlation and geological evidence from surrounding areas suggest they were likely derived and/or recycled from the Canadian Shield and the Appalachian orogenic belt, and the influx of clastics from the Appalachian orogenic belt to the east did not start until the Late Mississippian (Chesterian). Additionally, additional sources, such as the Nemaha Ridge and Ancestral Rocky Mountain to the west, are needed to account for a marked enrichment of Late Paleoproterozoic (1600-1800 Ma) seen in Late Mississippian strata. New detrital zircon data from this study provide further constraints for continental-scale sediment dispersal patterns across Laurentia and insights into Paleozoic paleogeographic reconstruction.