Colluvial deposits in dry valleys of southern England as proxy indicators of paleoenvironmental and land-use change

Investigations of colluvial sequences infilling the dry valleys of the southern English chalk escarpment have been undertaken since the late 1950s. Chalkland environments are characterized by a rich prehistoric cultural record and, because of poor pollen preservation in the highly calcareous chalkland sediments, molluscan analysis of such deposits has frequently been undertaken to reconstruct past land use and environment. Archaeologists often base their interpretations of past chalkland environments on these reconstructions. In order to test the value of this proxy data source, seven dry valley systems in southern England were investigated using a combination of lithostratigraphic and biostratigraphic techniques. The results of this study demonstrate that patterns of sedimentation are similar within valley systems, but that the mechanisms and chronology of deposition vary between valleys. The differences are probably caused by a combination of factors, including variations in past land use, the impact of storm activity, and local topography. It can therefore be argued that it is unwise to use dry valley sequences and their accompanying biological assemblages for regional environmental reconstruction, although the data are invaluable when examining land use on a local level—the scale at which most archaeological projects in the United Kingdom are carried out. © 2003 Wiley Periodicals, Inc.