Investigations into a later prehistoric ditch system in an area of Wessex about 15 km. south-west of Salisbury are described. The main objectives were to study the past environment of the earthworks at various stages in their history and to investigate their form and how they may have functioned. The two parts of the system studied were just south of Blagdon Plantation, Pentridge, Dorset, and on Knoll Down, Damerham, Hants. Excavations, study of soil and sediment macromorphology, and molluscan analysis were the main techniques used.
At Blagdon Plantation the earthwork lay in an area in which there was no trace of earlier fields. The bank was of simple dump construction, the ditch shallow and flat-bottomed, possibly unfinished. The molluscan sequence prior to the construction of the earthwork indicated a succession from closed woodland to stable grassland. The ditch sequence showed no trace of shading, and there was no indication of a former hedgerow on the bank crest. At Knoll Down, the earthwork crosses lynchets of an Iron Age field system, dated by potsherds from the ancient ploughsoil sealed beneath the bank. In one profile, lynchet deposits with an open-country molluscan fauna preceded the bank, and in some sections clear ploughsoils were present. A short episode when the area was under grass immediately preceded the earthwork. At one point, where there was no accompanying buried soil, deeply incised ploughmarks were present at the base of the bank, interpreted as clearance- or marking-out lines, possibly of a symbolic nature. The bank was of simple dump construction, the ditch deep, steep-sided, and with a narrow, flat bottom. There was no indication of a hedge. An earlier, smaller ditch, which may have held a wooden palisade, had been backfilled deliberately. These changes, which may reflect friction between different groups of people on various scales, took place in a prevailing environmental background of open country.