NHER 45167 (Cropmark and Earthwork record) - Cropmarks of a C-shaped enclosure, polygonal enclosure and pit of unknown date

October 2006. Norfolk NMP
Cropmarks of a C shaped ditch, a polygonal enclosure ditch and a pit of unknown date are visible on aerial photographs (S1-S3). These cropmarks are centred on TG 3072 1004. It is not clear whether the C-shaped ditch is part of an incomplete ring ditch or a monument in its own right. Its ditch is 2m wide and if it formed a complete ring ditch it would be sub-circular in plan with an external diameter of 24m. Only the western half of the ring is present forming a C-shaped ditch cropmark. A narrow polygonal ditch cropmark appears to form an enclosure that closely follows the western outer edge of the C-shaped ditch. To the east of the C-shaped ditch is an irregular pit cropmark that measures 25m by 18m. Several more pit cropmarks are present to its north and it is likely that it is an extraction pit to provide building materials for the adjacent medieval to post medieval road (NHER 45128). The pit cropmark is completely separate from the C-shaped ditch and does not appear to be responsible for the loss of the eastern half of a possible ring ditch. These cropmarks are located on the parish boundary between Great and Little Plumstead and Postwick (formerly Little Plumstead and Witton). The visible cropmark forming the C-shaped ditch and its polygonal enclosure lies almost completely in Little Plumstead parish.

These cropmarks are very unusual and several different interpretations can be proposed. The first possibility is that the C-shaped ditch was originally a complete ring ditch relating to a Bronze Age round barrow. Extant round barrows were often used as markers for parish boundaries and it is not unusual for ring ditches or barrow earthworks to occur on their line. The position of the C-shaped cropmark mainly on one side of the parish boundary may explain its unusual form. It is possible that historical land use on either side of the boundary was sufficiently different for the eastern half to have been ploughed away while the western part remains visible as a cropmark. It is not clear whether or not the polygonal ditch flanking the C-shaped ditch is also cut by the parish boundary. The large pit might be either a later or deeper feature that has survived the agricultural erosion process.

Alternatively it is possible that the C-shaped ditch was constructed as such and never formed a complete circuit. The first possibility here is that it relates to an unusual class of Neolithic or Bronze Age henge monument. A C-shaped ditch of similar size and form has been recorded close to other Neolithic to Bronze Age monuments at Roughton (NHER 38501) with a further example known from Essex (S4). It is possible that the polygonal ditch around the western side of the feature was constructed at a later date to separate the earthworks associated with ditch from the surrounding landscape. It these cropmarks do relate a prehistoric monument it is possible that their relationship to the parish boundary and extraction pit are entirely coincidental.

A third possibility is that all three of these cropmarks are contemporary. The C-shaped ditch and polygonal enclosure may have been deliberately constructed around the western side of the extraction pit at, or close to, the time when it was originally dug in the medieval to post medieval period. However the exact form and function of these cropmarks remains uncertain.
J. Albone (NMP), 19 October 2006