2018:771 - Knockbrack 2, Mayo

The site was identified during archaeological testing Stage (i) of the proposed N5 Westport to Turlough Road Project (A0069:E004621) undertaken by Archaeological Consultancy Services Unit in August 2018 as an addendum to testing undertaken in 2015. Due to very poor ground conditions the area was inaccessible when the main programme of test trenching was undertaken, but the dry weather in the summer of 2018 resulted in much improved conditions. The excavation was carried out between 21 November and 6 December 2018.

An area measuring 385m² was stripped of topsoil and excavated at Knockbrack 2. The site sloped from north to south and was located in bogland, with the remains of a burnt mound (F03) located at the margin of a ridge between marl and peat and a stony grey boulder clay. This sub-circular mound contained a high volume of heat-shattered sandstone and charcoal, measured 8.45m north–south by 8.15m and survived to a height of 0.6m. The burnt mound was sealed by peat (F01) and was removed onto the natural subsoil (F02). A rectangular stone- and timber-lined trough (F04), measuring 1.42m north-east/south-west by 0.75m and 0.45m in depth was exposed below the burnt mound. It was defined by well-preserved timbers and a large upright stone at the north-eastern end. A concentration of moss was found behind the side timbers and was probably used to filter the water as it entered the trough, while the base was a mix of some flat stones and gritty white clay representing accumulated debris from the burnt sandstone. The trough was filled with a loose, black/grey clay with burnt stone, charcoal and charred wood (F05). A pile of wood (F06) that included roots but also some worked roundwoods was located approximately 1m to the south-west of the trough. This timber was in all likelihood intended for use as firewood.

Radiocarbon dates have been obtained from two samples of charcoal: one sample was recovered from the base of the burnt mound (F03) and the other from the fill (F05) of the trough F04. The charcoal was identified as alder and hazel respectively by Dr Ellen O’Carroll. The burnt mound (F03) was dated to 1954–1767cal BC (3540±30BP; Beta-518393) and the fill (F05) at the base of the trough (F04) was dated to 2028–1884 cal BC (3590±30BP; Beta-518394). This would suggest an Early Bronze Age date for the site. No finds were recovered from this site.

The site can be classified as a fulacht fiadh and similar sites are located in the vicinity. Knockbrack 3 was located 61m west of Knockbrack 2 and Knockbrack 4 was located 90m west of Knockbrack 2. Thirty-five fulachtaí fiadh had been previously excavated on this scheme. An additional four were excavated during the current phase of works bringing the total to 39.

Archaeological Consultancy Services Unit, Unit 21, Boyne Business Park, Greenhills, Drogheda, Co Louth