| Summary : Excavations at Greyhound Yard in 1984-6 revealed an arc of large post-pits whch are believed to represent part of the south-west side of a massive timber palisaded enclosure of later Neolithic date. The earliest feature on site is a single pit, which was cut by one of the later post pits. 21 post pits were identified in the excavated area, and were associated with a flanking gulley lying just outside the enclosed area to the west. The post pits were 3-6 metres long and 2-3 metres wide, with a maximum depth in the natural chalk of 2.8 metres. Each had a vertical eastern face, and a long sloping ramp on the western side. Their fills included some residual early Neolithic material, while the backfill of the post pits featured Grooved Ware and some Peterborough Ware sherds. Early Bronze Age material, including collared urn sherds, clearly post-dated the monument. The posts, of oak and each 1 metre in diameter and spaced about 1 metre apart, appear to have been burnt in situ. A series of radiocarbon dates offer a date range of circa 2900-2340 BC (calibrated). The gulley was of more irregular construction, varying between 1 and 2 metres wide, and a maximum of 30 centimetres deep. Assuming the arc represents a circle, the proposed enclosure would be circa 290 metres in diameter, enclosing some 7 hectares. However, some further pits exposed to the north, in Church Street, in 1982-3 are of similar construction and have yielded a similar radiocarbon date. Their location would suggest an enclosure of some 380 metres maximum diameter, enclosing some 11 hectares. Further excavations to the rear of 1-2 Acland street in 1989 found five further posts belonging to the monument. It was also noted further south beneath the Repository, but unexpectedly at the east end of the trench where three post pits were found. The alignment had changed markedly, swinging to the east, which contradicts earlier interpretations that the monument is an arc or circle. |