2011:087 - CARRIGTOHILL, Cork

An assessment for a proposed two-classroom extension to St Mary’s Boys National School, Carrigtohill, was undertaken at the request of the County Council. A subsequent condition of planning permission requested a test excavation of the development site. The extension is located near the site of a shell midden (CO075-068) excavated by Michael J. O’Kelly in the 1950s.

Three test trenches were opened on the site in the area of the proposed extension. The trenches were excavated using a 3-tonne mechanical excavator with a 1.5m-wide grading bucket. Testing in the area of the site was limited by the presence of services (water, sewerage etc.) and the depth at which the natural subsoil existed, (c. 1–1.3m below present ground level). The stratigraphy was similar throughout the site, the level of which appears to have been artificially built up. This was evident by the presence of modern fill and possible buried topsoil to a depth of 1.3m. The overburden contained plastic, red brick, crockery and glass. The natural subsoil appears to slope gently from north to south and consists of an orange/yellow silty sand material with few stones. Natural subsoil was exposed at the base of all the trenches. Three archaeological features were uncovered in Trenches 1 and 3.

A feature was uncovered in Trench 1 at a depth of 1.25m from present ground level at the eastern end of the trench. The linear feature extended under the northern and southern baulks. It measured 1.3m east–west and consisted of a mid-brown silty sand fill with charcoal flecks and few stones. A small section was manually excavated across the feature (1.2m east–west). The cut had a broad, V-shaped profile and measured 0.55m in maximum depth. A sherd of glazed medieval pottery, dating from the 13th–14th century, was recovered from the upper portion of the fill. A second cut feature was also uncovered at the western end of the trench and extended under the northern and western baulks. The fill appeared to be similar to that of the aforementioned linear feature. The exposed portion measured 0.7m north–south by 0.7m. This feature was not manually excavated. A feature was also uncovered at the western end of Trench 3 at a depth of 0.9m below present ground level. The fill was similar to that of the features exposed in Trench 1 and consisted of a mid-brown silty sand material. This linear feature ran north–south and extended under the northern, southern and western baulks. The exposed section measured 0.5m in width (east–west).

The use of a raft foundation during the construction phase of the development meant that any further impacts on archaeology were avoided. The archaeological features occur at a depth of between 0.9m and 1.25m below present ground level. The use of a raft allowed a 0.5m horizontal buffer between the top of the archaeology and the base of the raft. Monitoring of services was also undertaken under the same licence in 2011, during which time no archaeological finds or features were uncovered.

Tobar Archaeological Services, Saleen, Midleton, Co. Cork