2006:1473 - Sonnagh, Mayo

This site was excavated between 18 November 2005 and 24 March 2006. It was newly identified during centreline testing (A020/003) and was fully excavated in advance of the construction of the N5 Charlestown bypass. It was located at 71m OD.
The fulacht fiadh consisted of a mound of burnt stone and charcoal overlying the base of a substantial wood-lined trough. This was constructed of substantial split timbers. The trough base consisted of twelve large split planks, one associated corner stake and a fragmentary horizontal timber that may be the remains of the trough side. It had overall dimensions of 2.5m by 2.3m. This trough base rested on boulder clay and was overlain by compact peaty burnt-mound material. A 25m by 25m area adjacent to this fulacht fiadh produced disturbed archaeological remains including two patches of burnt-mound material associated with two substantial pits that may have acted as troughs. Three smaller pits were also excavated in this area.
These features partly overlay a series of foundation trenches and ditches. One structure consisted of two roughly concentric foundation trenches. The inner trench was subcircular in plan with an internal diameter of 4m. It had an average width of 0.6m and was 0.4–0.65m deep. Its fills included frequent stone, some of which may have acted as packing, and mixed light- and dark-brown silty gravel. The outer trench enclosed an area 8–9m in diameter but was irregular in plan. It was 0.9m wide by 0.5m deep. The fills from these trenches consisted of a light-brown and yellow gravel with frequent inclusions of small stones. Two chert waste flakes were present in the fill of the inner foundation trench. Five artefacts retrieved from the fill of the outer trench included a possible rubbing/sharpening stone, a chert waste flake and three pieces of struck chert. The area enclosed by these foundation trenches measured 4.1m by 3.3m.
These foundation trenches cut through an earlier oval ditch, which enclosed a space of 8.5m by 10.5m. This ditch measured 1.4m wide and 0.6m deep.
This ditch truncated a small C-shaped foundation trench in the north-west. The C-shaped ditch measured 0.7m wide and had a maximum depth of 0.6m. It enclosed an area of 3.5m. It may represent the foundation trench for a small hut. No finds were recovered from this feature.
Truncated portions of two separate ditches were found to the south of this complex. One of these measured 0.9m wide and 0.4m deep and survived to a length of 2m. Adjacent to this was a more substantial portion of a circular ditch, which was clearly truncated by the outer trench of Structure 1. This truncated ditch measured 0.8m wide and 0.54m deep and survived to a length of 8m.
A total of 96 artefacts were recovered from this excavation, the vast majority of which were either waste from the production of flint and chert tools or the tools themselves.