Excavation

Date 23 June 2010 - 14 July 2010

Event ID 881157

Category Recording

Type Excavation

Permalink http://canmore.org.uk/event/881157

HY 3727 3037 (Brough), HY 3723 3036 (Ditch), HY 3753 2966 (Swandro) A team from the University of Bradford, Orkney College (UHI) and City University New York cleaned, recorded and sampled three sites from 23 June–14 July 2010 as part of the ‘Orkney – Gateway to the Atlantic Project’. The project aims to investigate and record coastal sites in Rousay, Egilsay and Wyre which are threatened by rising sea levels and coastal erosion. The Mound of Brough The man-made mound at ‘Brough’,

also known as South Howe, on the SW shore of Rousay contains an eroding Iron Age broch and houses. These structures seem to be overlain by Late Norse buildings which in turn are overlain by 19th-century middens. This broch is only a few hundred metres away from the Broch of Midhowe (HY33SE 2). Coastal erosion has exposed the remains of a settlement mound that is surmounted by the ruins of the farm of Brough.

The active area of erosion extends for at least c70m along the low cliff face. In the centre of the eroding area are the remains of walling which appears to be the outer wall and entrance passage of a broch. This wall survives to a height of 2.5m and varies in width from 4.2m at its base to just under 3m at its highest point. Erosion to the W of this structure appears to be recent, with a cove-like zone extending 2m inland. This zone contained orthostats and flagging. A second zone of active erosion appears c20m to the E. Examination of this area revealed a number of walls; their construction strongly suggests that these remains represent a later phase of settlement, probably dating to the later medieval or early

post-medieval period. The aim of the 2010 season at South Howe was the

characterisation and examination of the potential of the surviving archaeology by tapestry excavation of the cliff exposure. The large expanse of exposed wall core that forms the apex of the visible mound was not cleaned and was left in situ in order to maintain the stability of the wall. Turf and slippage was removed to reveal the outer wall face and the

exposed wall core. To the E of this truncated wall a wall face ran N; this wall face turned at 90° into a second wall that appeared to run W into the mound and form the inner wall of a broch-like roundhouse. The N-oriented face is interpreted as the W side of an entrance passage. The in situ remains of a broken lintel stub projected from this wall. Midden containing 19th-century pottery, probably originating from the farm of Brough at the summit of the mound, appeared to seal the interior of the broch. The broch

seems to have suffered from one or more severe erosion events and this material may represent re-deposition from in situ deposits at the top of the mound. This area was not excavated and requires further investigation to resolve the depositional sequence. The elevations of the eroding cliff sections were photographically recorded, with geo-referenced markers

placed in each frame. This season formed Stage 1 of several years projected work on these exposed remains. The Ditch NE of Midhowe A fluxgate gradiometry survey of the area NE of the guardianship boundary of the Midhowe Broch by staff and students of Orkney College demonstrated

a clear magnetic anomaly running NE for c50m and then turning in a S–SSE direction. The strength of the anomaly was high, although the data suggested that this was a ditchlike feature of anthropogenic origin. An assessment trench, 9.55 x 2.8m, was machine-cut across the anomaly. When excavated, the ditch contained little in the way of cultural evidence, with no artefacts to suggest an infill date. Further geophysical survey after the excavation indicated that the ditch did not continue, but turned to form a small enclosure. The infill sequence suggests material being deposited from the NW. The uniform nature of the stone in the greater part of the ditch corresponds to the type seen in prehistoric clearance cairns. One possibility is that this ditch represents a field division associated with the broch, possibly designed to contain cattle.