2006:1472 - Sonnagh, Mayo

This site was excavated between 7 November and 12 December 2005. It was newly identified during centreline testing (A020/003) and was fully excavated in advance of the construction of the N5 Charlestown bypass.
The site consisted of a horseshoe-shaped burnt mound measuring 10.3m east–west by 16m by 0.64m thick. It was located at 71.5m OD. The mound consisted of a fairly homogeneous deposit of small fire-shattered stones in a charcoal-rich silty matrix. A platform or trough base occurred within the mound and a well-preserved wood-lined trough was sealed by the mound within the natural peat.
The platform/trough occurred within the north-east side of the mound 0.3m north-east of the main trough. It had overall dimensions of 1.3m by 0.8m and consisted of seven poorly preserved timbers laid parallel and held in place by four corner posts that were secured by wedges. It was sitting on 0.3m of mound material.
The main trough was rectangular in plan with overall dimensions of 2.2m by 1.4m and an internal depth of 0.25m. It was filled with mound material and displaced timbers, including some charred timbers.
This trough was rectangular in plan with overall dimensions of 2.2m by 1.4m and an internal depth of 0.25m. It was constructed on the natural boulder clay within a peat layer. The four corner posts were driven into the boulder clay and were supported by stakes or wedges, which held the roundwood sides in place.
The base of the trough was on a 10° slope that was levelled up using some timbers. These were overlain by a layer of moss which had a maximum thickness of 0.07m. A base of split timbers rested on this moss layer and were fitted tightly against the basal side timbers and the corner posts. The timbers had wedge cut and notched ends to secure them tightly. The ends of the roundwood side timbers were also cut to wedges and notched to form tight joints at the corners.