Patterned ground and superficial deposits at Hare Park, Swaffham Bulbeck, Cambridgeshire, England

Patterned ground on chalkland at Hare Park, Cambridgeshire, includes patterns associated with a periglacial climate (stripes, nets), but also a type of pattern distinctly differing from these. These patterns are seen in the Fort field, to the east of the Hare Park ridge, which extends northwards across the Chalk escarpment and from the Anglian till plateau to the south. Three valleys are present in the Fort field, draining to the NE. Stripes and nets are associated with the two older valleys, and are associated with incision of streams of the Chalk escarpment. The other patterns, developed on the surface of the Moulton Head, consist of depressed rings and arcs forming wide and low ditches. These are shown to be filled with sandy sediment. They result from Chalk solution associated with pools formed by groundwater released from a perched aquifer in the Chalk. The pools pre-dated the head, with the depth of depression reflecting the degree of subsequent subsidence, and the patterns are related to the presence of sand bodies older than the head. The Fort field patterns are related to the superficial deposits immediately to the west by analysis of boreholes and local geological records. The Moulton Head interdigitates with clays interpreted as being of proglacial origin, as are the Head Gravels of Hare Park. The proglacial origin is related to the Fenland mid-Wolstonian Tottenhill glaciation at c. 160 ka. The relation of the Palaeolithic archaeology of Hare Park to the deposits is considered and compared with records of palaeoliths in proglacial sediments in southern Fenland.