2001:259 - CORRSTOWN, Hopefield Road, Portrush, Derry

The site, at Corrstown, Hopefield Road, within the southern limits of Portrush town, comprises four arable fields some 18.32 acres in extent, within the northern field of which (Field 4) lie the remains of a cropmark enclosure. Excavations undertaken by Alan Reilly in advance of housing development in Magheramenagh immediately west of the site during 1999 revealed possible prehistoric houses and an Early Christian souterrain (Excavations 1999, No. 130).

As part of a planning application for a residential housing development an assessment was undertaken at the site. Proposed development is planned for two phases, the first seeing development of the eastern flank of the site, comprising a 32m-wide stretch through the eastern side of Fields 1–3 along Hopefield Road, followed by a second phase in which the remainder of the site would be developed. The Phase 1 assessment comprised a geophysical survey using a fluxgate gradiometer within Field 4 to locate the cropmark site, surface finds collection and excavation of four test-trenches through the Phase 1 area. This work was carried out on 12–13 December 2001. Planned Phase 2 assessment of the remainder of the site will take place along with comprehensive surface artefact collection from January 2002.

The geophysical survey, carried out by Ken Hamilton and Malachy Conway, utilised an FM36 fluxgate gradiometer with ST1 sample trigger with data collected at 0.5m intervals, along parallel transects 1m apart over an 80m2 grid, and was processed using Geoplot 3.0. Soil cover in Field 4 consisted of dark brown sandy clay overlying drift geology of boulder clay and an igneous solid geology. The results were affected by the geological conditions on site, resulting in a broad band of high magnetic signals and low magnetic signals in the raw data. A semicircular feature was revealed in the south-east quadrant of the survey grid, 20m in diameter, characterised by a high magnetic signal (+30nT) to the east, petering out towards the west. This appears to represent the location of the cropmark site. The survey also revealed several linear anomalies representing possible field drains; however, in the south-west corner of the survey grid a cluster of small negative anomalies, including two small (5m) rectilinear features (positive signals) and an L-shaped negative anomaly with positive signals on either side of it (15m x 10m), suggested possible souterrain passageways.

The Phase 1 assessment consisted of mechanical excavation of four test-trenches as well as monitoring of four engineering test-pits located along the west side of the Phase 1 area. All four trenches displayed dark brown topsoil on average 0.25m deep over orange-brown sandy clay subsoil. No features or deposits of archaeological significance were recovered. Monitoring of four engineering test-pits along the west side of the Phase 1 area failed to reveal anything of archaeological potential. Surface material recovered from the Phase 1 area across Fields 1–3 largely comprised flint, most of it patinated orange; the assemblage, presently being examined, contained a number of artefacts, particularly scrapers. No pottery of medieval or prehistoric character was recovered from the Phase 1 area.

Unit 22, Boyne Business Park, Greenhills, Drogheda, Co. Louth