Trench B

Trench B was opened at a chambered tomb located on the hill known as Grand Monceau. A sketch of the tomb had been made by F.C. Lukis in 1839, and in December 1840 the interior of the chamber was excavated by John W. Lukis. Several fallen orthostats were raised during this early examination, but finds were few, amounting only to fragments of vases and one ground stone tool.

In 2008 a trench measuring 5m x 1.5m was laid out at right angles to the long axis of the chamber, on its northern side. The aim was to investigate the mound which topography suggested surrounded the chamber and the associated buried land surface.

During removal of the first 5cm spit after turf clearing, an area of densely root-matted soil was encountered. This material was found to be gravelly in patches, was lighter in colour than the overlying layer and ran east to west across the entire width of the trench. Bottle glass indicated a recent date, and it is probable that this feature has no connection with the original construction of the tomb, but rather represents material upcast from the interior chamber during the 19th century excavation.

Underlying this upcast was a layer of sand, continuous in the southern half of the trench, i.e. nearest the chamber, but patchy in the northern half where it varied in colour from yellow to mid-brown. After removal of the whole sand layer, the reason for this became apparent. In the eastern section, at a distance of approximately 3m from the chamber, a series of at least three ridges and furrows was revealed. These features indicate cultivation of the land immediately surrounding the tomb in which the sand became mixed with a darker soil beneath. A series of thin sand-filled plough marks was also noted within the darker underlying layer.

Removal of the sand layer revealed a rounded granite block lying some 2.75 metres from the northern end of the trench. This was provisionally interpreted as a kerb stone. To its north, the soil was dark brown. This layer was assumed to be the Neolithic land surface on which the chambered tomb was built. It was first encountered at a depth of approximately 28cm, and was found to be 22cm deep against the northern baulk. Beneath was orange-coloured eroded granite bedrock. To the south of the stone, that is to say, between it and the chamber orthostats, the same dark soil was encountered but with a smaller stones. These were four courses deep in some areas, were piled without particular care, and were more numerous and larger and more deeply piled in the area closest to the tomb. Immediately behind one of the in situ orthostats, cuts were seen in the bedrock perhaps to hold large packing stones.

In order to further investigate this arrangement of stones, the southern half of the trench was extended in width 1 metre to the east and 0.5 metres to the west. The spread of stones behind the orthostats was found to continue in both directions. Two more possible kerb stones were also found in the eastern extension, though none were found further west.

Excavation at Trench B provided evidence that the chambered tomb had been set into the natural bedrock. Whilst there is no trace of a mound surrounding the monument, it seems probable that the orthostats were supported by large packing stones encircled by a low cairn-like arrangement of smaller stones. The whole structure is likely to have been bounded by a kerb of larger boulders, beyond which cultivation was practised at a later date.

Finds were not numerous in any part of trench B. The upper layers yielded modern refuse (e.g. bottle glass), quartz pebbles, marine shells and, at the bottom of the sand layer, a sherd of Normandy Gritty Ware. The dark, prehistoric layer beneath the sand yielded some 20-30 flint waste flakes. Small sherds of prehistoric pottery, including one decorated beaker sherd, were also found in the same level, mainly amongst the cairn-like arrangement of stones discussed above.

Four samples were taken for luminescence dating from the eastern baulk of the extended trench in order to determine the date of sand deposition over the prehistoric land surface. 

Text and photograph copyright Chris Scarre, Department of Archaeology, Durham University.