2018:770 - Knockbrack 3, 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 19 and 23 November 2018.

An area measuring 350m² was stripped of topsoil and excavated at Knockbrack 3, confirming the presence of a burnt mound. The site was located in a raised bog that formed at the base of an east–west ridge and was bordered by a stream to the south and west. The sub-circular mound (F03) consisted of heat-affected stone, mainly sandstone, in compacted black/grey clay with some large stones and frequent charcoal. It measured 6.23m north–south by 5.1m and survived to a height of 0.24m. The spread was fully excavated and a single trough (F05) was exposed below the burnt mound. The sub-oval trough contained burnt mound material (F04) that included three unworked roundwood timbers and a large, unburnt flat stone (sandstone).

Radiocarbon dates have been obtained from two samples of charcoal: one sample was recovered from the base of the burnt stone mound (F03) and the other from the fill (F04) of the trough F05. The charcoal was identified as alder and hazel respectively by Dr Ellen O’Carroll. The burnt mound (F03) was dated to 2835–2477 cal. BC (4050± 30BP; Beta-518395) and the fill (F04) of the trough (F05) was dated to 2851–2491 cal. BC (4070±30 BP; Beta-518396). This would suggest a Late Neolithic date for the site.

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