SDO21224 - Magnetometry Survey at Five Long barrows near the Dorset Cursus

‘Five long barrows located close to the terminals of the Dorset Cursus were subject to geophysical surveys during 2023. Near the north-east terminal, survey of the ploughed out long barrow Pentridge 23 has helped to clarify the plan of the ditches, as well as revealing an intriguing feature central to the mound. Just to the south, Pentridge 21 and 22 share the similar alignments and are set end to end, directly adjacent to and aligned on the north-east terminal of the Dorset Cursus. The survey has clarified the nature of the gap between the ditches of the two monuments, as well as showing that the north end of the mound of Pentridge 21 has been truncated. Subtle changes in the alignment of the ditches and the mounds provide possible clues about the construction techniques of the barrows. Finally, the character of the ditches around the associated round barrow could indicate an early, possibly Neolithic, date for this monument. A short distance to the south, a survey which aimed to plan the flanking ditch to the west of the Pentridge 20 long barrow was thwarted by a modern service pipe. At the south-west end terminal of the Dorset Cursus, the survey unexpectedly revealed what are probably two phases of construction of long barrow Gussage St Michael 11. An initial long barrow with a U-shaped ditch appears to have been later extended to the south-east, to form a long barrow of a more traditional shape, demonstrating close parallels with the extension of Pentridge 21 at the other end of the cursus.’