Recognizing Vertical and Lateral Variability in Terrestrial Landscapes: A Case Study from the Paleosols of the Late Pennsylvanian Casselman Formation (Conemaugh Group) Southeast Ohio, USA

摘要

The Upper Pennsylvanian Casselman Formation of southeastern Ohio contains four distinct paleosol types that formed in alluvial systems within the distal Appalachian foreland basin. The properties of these paleosols as well as their small-scale lateral and vertical variations were studied to interpret the paleoenvironmental and paleoecological conditions within the alluvial settings in which they formed. The ichnofossils and pedogenic features preserved within the paleosols of the Casselman Formation record the local climactic, hydrologic, biotic, and topographic changes that occurred in the region during the Late Pennsylvanian. The four paleosols types of the Casselman Formation are interpreted as Alfisols (Type A, Type D), Vertisols (Type B), and Inceptisols (Type D). The four paleosol types indicate different degrees of changes in local moisture regimes including water table fluctuations due to seasonal precipitation and flooding events. The assemblages of ichnofossils within the paleosol types were produced by both soil arthropods and a diverse array of plants that formed part of the different soil ecosystems present within the alluvial environment. Although regional-scale studies are important for understanding the Late Pennsylvanian world, small-scale studies are also necessary to fully understand the local pedogenic, paleoenvironmental, and paleoecologic consequences of global scale changes in paleoclimate and paleogeography.