دانلود کتاب Characteristics of the Mid-Carboniferous Boundary and Associated Coal-Bearing Rocks in the Appalachian Basin: Morgantown, West Virginia to Chattanooga, Tennessee, July 19-27, 1989

About The ProductPublished by the American Geophysical Union as part of the Field Trip Guidebooks Series. In the northern Appalachians, the boundary between the Mississippian and Pennsylvanian systems falls within a complex sedimentary sequence spread across a rapidly-subsiding depositional trough and an adjacent, more stable craton margin. Sediment source areas lie in a more-or-less continuous semicircle from southeast to north of the basin. In addition, the Upper Mississippian-Lower Pennsylvanian sequence is interrupted by extensive erosion related to epeirogenic upwarping of the region. Biostratigraphically, the systemic boundary is placed at the first occurrence of the floral form Neuropteris pocahontas (D. White) of floral zone 4 as defined by Read and Mamay (1964). However, because of the widespread disconformable nature of the contact, the basal Pennsylvanian flora is often younger. Content: