The Delaware Geological Survey (DGS) has published a new geologic map of the Millsboro and Whaleysville areas in central Sussex County titled Geologic Map of the Millsboro and Whaleysville Quadrangles, Delaware.
The geological history of the surficial units of the Millsboro Quadrangle and
Delaware portion of the Whaleysville Quadrangle was the result of deposition of the
Beaverdam Formation during the late Pliocene and its subsequent modification by
erosion and deposition related to sea-level fluctuations during the Pleistocene and late
Pleistocene upland swamp and bog deposition. The geology at the land surface was then
further modified by periglacial activity that produced dune deposits and Carolina Bays in
