Abstract Ohio 7 is a divided highway with wide shoulders adequate for parking at the exposures. Access to the area from western Penn-The Wellsville Hill section consists of two large roadcuts sylvania and West Virginiais by bridges across the Ohio River at located along Ohio 7 just south of Wellsville, Ohio, on the East Liverpool, Ohio, to the north and at Steubenville, Ohio, to Wellsville Ohio-West Virginia 7½-minute Quadrangle (Fig. 1). the south of the field area.

Abstract During the Pleistocene, the Laurentian Ice Sheet extended southward into western Pennsylvania. This field trip identifies a number of periglacial features from the Pittsburgh Low Plateau section to the Allegheny Mountain section of the Appalachian Plateaus Province that formed near the Pleistocene ice sheet front. Evidence of Pleistocene periglacial climate in this area includes glacial lake deposits in the Monongahela River valley near Morgantown, West Virginia, and Sphagnum peat bogs, rock cities, and patterned ground in plateau areas surrounding the Upper Youghiogheny River basin in Garrett County, Maryland, and the Laurel Highlands of Somerset County, Pennsylvania. In the high lying basins of the Allegheny Mountains, Pleistocene peat bogs still harbor species characteristic of more northerly latitudes due to local frost pocket conditions.

ABSTRACT During the Pleistocene, the Laurentian Ice Sheet extended southward into northwestern Pennsylvania. This field trip identifies a number of periglacial features from the Appalachian Plateaus and Ridge and Valley provinces that formed near the Pleistocene ice sheet front. Evidence of Pleistocene periglacial climate in this area includes glacial lake deposits in the Monongahela River valley near Morgantown, West Virginia, and Sphagnum peatlands, rock cities, and patterned ground in plateau areas surrounding the Upper Youghiogheny River basin in Garrett County, Maryland, and the Laurel Highlands of Somerset County, Pennsylvania, USA. In the high-lying basins of the Allegheny Mountains, Pleistocene peatlands still harbor species characteristic of more northerly latitudes due to local frost pocket conditions. Pleistocene fauna preserved in a cave deposit in Allegany County, Maryland, record a diverse mammalian assemblage indicative of taiga forest habitat in the Ridge and Valley province.

Abstract For the biostratigraphy of mixed continental-marine and purely continental sections in the palaeotropical belt of Euramerica, 9 insect and 8 conchostracan zones are newly defined or improved. These zones encompass the time interval from the Early Pennsylvanian (middle Bashkirian) up into the early Permian (early Asselian) of the Euramercian biotic province. They are linked as much as possible to the marine Standard Global Chronostrigraphic Scale by common occurrences of insects and/or conchostracans with conodonts in mixed marine-continental sections as well as by the thus far available and reliable radioisotopic ages of associated volcanic rocks. This insect and conchostracan zonation is an alternative tool to the well-established macro-plant biostratigraphy of the Pennsylvanian. In contrast to the latter, only single specimens of insects or conchostracans, even if more rare than plant remains, allow biostratigraphic dating with a similar high temporal resolution.