Altitudinal trends of periglacial geomorphic features in the Appalachian Highlands, Eastern U.S.

Abstract

Periglacial features, e.g., solifluction deposits, sorted patterned ground, blockfields, and cryoplanation terraces, are widespread throughout the Appalachian Highlands of the eastern USA. Although most of these geomorphic features are considered to be relict, their spatial distribution can be used to discern the extent of past periglacial conditions. Numerous examples exist from the literature linking periglacial features to climate, snowline and Quaternary history in Europe, North Africa, South America, the Middle East, and the cordillera of western North America. A study integrating a systematic regional inventory of periglacial features and their altitudinal trends has not been conducted for the Appalachian Highlands. We examine and relate the elevation trends of selected periglacial features from Maine to North Carolina to topography, paleoenvironmental reconstructions, permafrost occurrence, and climate observations from a transect on Appalachian summits. The results of this work are used to cast new light on the extent and magnitude of Pleistocene paleoperiglacial conditions in the eastern USA and to clarify the origins of hypothesized periglacial geomorphic features in the region. The results of this work also have applications to active periglacial regions, such as those that exist in Alaska, that are undergoing modern climate change.