| Summary: | Frost fissures, filled with wind‐abraded sand and mineral soil, and numerous small‐scale non‐diastrophic deformations, occur in the near‐surface sediments of the Pine Barrens of southern New Jersey. The fissures are the result of thermal‐contraction cracking and indicate the previous existence of either permafrost or seasonally‐frozen ground. The deformations reflect thermokarst activity that occurred when permafrost degraded, icy layers melted and density‐controlled mass displacements occurred in water‐saturated sediments. Slopes and surficial materials of the area reflect these cold‐climate conditions. Optically‐stimulated luminescence permits construction of a tentative Late‐Pleistocene permafrost chronology. This indicates Illinoian, Early‐Wisconsinan and Late‐Wisconsinan episodes of permafrost and/or deep seasonal frost and a Middle‐Wisconsinan thermokarst event. Copyright © 2007 John Wiley & Sons, Ltd.
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