Archaeological Evaluation

Date November 2007 - March 2008

Event ID 578708

Category Recording

Type Archaeological Evaluation

Permalink http://canmore.org.uk/event/578708

NO 2026 2243 An investigation into the impact of polytunnels on cropmark monuments was carried out in a polytunnel covered field in November 2007 and March 2008. The area contains a souterrain (NO22SW 12) known from cropmark evidence. It is one element of what is probably a larger open settlement with other souterrains and structures, which are collectively protected as a scheduled ancient monument (SAM 7222). The souterrain was investigated by GS Maxwell in 1982.

The project aimed to establish the present position of all ground-breaking elements of the polytunnel prior to its

demolition and removal, to recover evidence for the nature and extent of any changes to the condition of the site and to investigate the present condition of the souterrain. The project was therefore undertaken in two phases.

Aerial photo rectification, survey and test pitting prior to dismantling.

Evaluation trenching following removal of the polytunnels.

Survey established the positions of the ground-breaking elements of the polytunnels prior to their removal. Two main elements were recorded, the support posts and the irrigation pipes. Test-pitting while the superstructure was in place established the depth of excavations associated with the polytunnel construction.

Test-pits were hand-excavated and revealed that the support posts had penetrated the subsoil to varying depths of up to 0.35m and were spaced at intervals of 2.2m along the wall lines of the polytunnels. The irrigation pipes were buried in a machine-dug trench at a depth of 0.35m below the surface.

Two trial trenches, totalling 54m2, were excavated by machine across the known location of the souterrain and

were positioned to intersect with the former location of ground-breaking elements of the polytunnel structures. The souterrain was lined with stone and measured 1.2m–2.6m wide by up to 1.7m deep; a stone paved floor was recorded in only one sondage. A buried soil and an associated cut feature appeared to lie over the souterrain. This latter feature measured at least 7.9m across by 0.6m deep but its extent and purpose were not established.

Polytunnel support posts were found to have impacted upon the souterrain to a depth of between 0.2m–0.3m. One of them cut through the upper part of the souterrain wall. An irrigation pipe trench was also found to have cut across the upper fill and wall of the souterrain and across the associated feature.

Archive: RCAHMS (intended).

Report: Historic Scotland, Perth and Kinross SMR and RCAHMS

Funder: Historic Scotland

Ian Suddaby (CFA Archaeology Ltd), 2008