Reasons for Designation
Cross dykes are substantial linear earthworks typically between 0.2km and 1km
long and comprising one or more ditches arranged beside and parallel to one or
more banks. They generally occur in upland situations, running across ridges
and spurs. They are recognised as earthworks or as cropmarks on aerial
photographs, or as combinations of both. The evidence of excavation and
analogy with associated monuments demonstrates that their construction spans
the millennium from the Middle Bronze Age, although they may have been re-used
later. Current information favours the view that they were used as territorial
boundary markers, probably demarcating land allotment within communities,
although they may also have been used as trackways, cattle droveways or
defensive earthworks. Cross dykes are one of the few monument types which
illustrate how land was divided up in the prehistoric period. They are of
considerable importance for any analysis of settlement and land use in the
Bronze Age. Very few have survived to the present day and hence all well-
preserved examples are considered to be of national importance.
The cross dyke 420m west of Chanctonbury Ring hillfort survives comparatively
well, despite some disturbance by downland tracks, and has been shown by
part excavation to contain archaeological remains and environmental evidence
relating to the ways in which it was constructed and used. The cross dyke is
unusual in that it has been dated to the Roman period, providing important
evidence for the continuing use of this form of land boundary beyond the
prehistoric period. The monument forms part of a group of prehistoric, Roman
and early medieval earthworks situated on Chanctonbury Hill, including a
hillfort, Romano-Celtic temple, a further cross dyke and a number of round
barrows and hlaews or Saxon barrows, which are the subjects of separate
schedulings. The close association of these monuments illustrates the changing
relationship between ceremonial and burial practices and land division in
this area of downland over a period of c.1,500 years.
Details
The monument includes a north-south aligned cross dyke which runs for c.106m
across a chalk ridge which forms part of the Sussex Downs. The cross dyke has
a ditch c.5m wide and c.0.7m deep, flanked on its eastern side by a bank c.7m
wide. This survives to a height of c.0.5m. To the north, the earthworks fade
out gradually as the ground slopes away, whilst the southern end is formed by
a well-defined, rounded terminal. The cross dyke has been levelled near its
centre and towards its southern end by two downland tracks which cross the
monument, although the ditch will survive here in buried form. The bank also
shows signs of part disturbance by World War II training activities.
The monument was partly excavated in 1977, when the ditch was shown to have
been originally flat bottomed, with an asymmetrical profile, and the bank
constructed of simply-dumped chalk rubble and flinty-clay. A sherd of pottery
found at the base of the bank indicated that the cross dyke may date to the
Roman period (c.AD 43-450).
MAP EXTRACT
The site of the monument is shown on the attached map extract.
It includes a 2 metre boundary around the archaeological features,
considered to be essential for the monument's support and preservation.
