Periglacial Appalachia: Paleoclimatic and Geocryological Implications of Blockfield Elevation Gradients, Eastern U.S.A.

The elevation of Appalachian blockfields south of the Last Glacial Maximum border parallels regional gradients of contemporary mean July, summer, and annual temperature. July temperature reductions inferred from paleoecological studies indicate that the median elevations of blockfields throughout the Appalachians lay at or above timberline during the Last Glacial Maximum (LGM). Paleotemperatures calculated using known Appalachian lapse rates and published LGM temperature departures indicate that blockfields in the study area were formed in association with permafrost. Allochthonous blockfields appear to be constituent elements of periglacial "form communities" developed under severely cold conditions, and are useful indicators of Pleistocene permafrost conditions.