The general setting is the well-developed drumlin landscape that was left behind following the decay of the last ice in County Down. The drumlins vary in height and rise above the lakes and marshy ground that separate them. Some of this marshy ground lies around the 7-8m contour in the Ards area and was submerged during two phases of marine transgression in the Late Glacial and Holocene periods. Following retreat of the Late Glacial sea, a freshwater, or possibly at first a slightly brackish, lake remained. An unbroken succession of typical and clearly developed Late Glacial and Holocene sediments accumulated in this basin. This was abruptly ended when a grey lagoon clay, marking the second marine transgression, buried the fen communities. Subsequently the whole deposit was buried by inland movement of a beach bar, which helped compress the underlying deposits. Eventually continuing isostatic recovery raised all the deposits above the reach of the sea. Since then, further sea level readjustment has involved the erosion of these raised beaches and wave attack at Roddan's Port has led to the re-exposure of the greater part of the formerly buried lake deposits.
