An eolian dust origin for clastic fines of Devono-Mississippian mudrocks of the greater North American midcontinent

ABSTRACT Upper Devonian and Lower–Middle Mississippian strata of the North American midcontinent are ubiquitously fine-grained silt-rich, comprising both so-called shale as well argillaceous limestone (or calcareous siltstone) that accumulated in Laurentian epeiric sea. Although long recognized recording marine deposition, origin transport siliciclastic material these units remains enigmatic because they do not connect to any proximal deltaic feeder systems. Here, we present new data on grain size, whole-rock geochemistry, mineralogy, U-Pb detrital-zircon geochronology from across Oklahoma; then integrate with models surface wind circulation, refined paleogeographic reconstructions, correlations greater test hypothesis transported fraction system. The exclusively very fine silt sand clear detrital origin, widespread distribution over large regions sea, Appalachian sources, setting subtropical arid belt far-removed contemporaneous systems most consistent eolian dust lofted subaerial delta plains orogen incorporated into subaqueous depositional Delivery was minimally chemically weathered Devono-Mississippian seas likely provided essential nutrients stimulated organic productivity commonly organic-rich units.