2014:432 - Corrib Onshore Pipeline, Aughoose, Glengad, Bellagelly and Bellanaboy, Mayo

Monitoring was undertaken during the construction phase of the Corrib Onshore Pipeline from July 2011 to June 2014 under licences 11E0214 and 11R0090. All ground disturbance work and tunnel arisings associated with the construction of the tunnel for the pipeline project were monitored. The route was approximately 8.3km long from the landfall (Glengad) to the Bellanaboy Bridge Gas Terminal. The onshore element of this project took place in Glengad, Aughoose and Bellagelly townlands while the tunnel was excavated below the bed of Sruwaddacon Bay.

Monitoring was undertaken to determine the presence (if any) of below-ground or previously unknown archaeological features. This work followed previous monitoring carried out at Glengad and Broadhaven Bay in 2002, 2005, 2008 and 2009 and testing carried out at Aughoose in 2010. No archaeological features or artefacts were identified during the monitoring works.

Palaeo-environmental analysis of the tunnel arisings provided a rare opportunity to examine sealed organic deposits along what is now seen as a dynamic coastal environment. While no evidence was identified during the monitoring programme for the presence of human activity within and around Sruwaddacon Bay, the dating and identification of wood and organic samples has contributed to a small body of information that has helped reveal the vegetational history of the bay during the post-glacial period.

The environmental results show that Sruwaddacon Bay was not always a wide, treeless environment with extensive tracts of bogland. The surrounding area was dominated by trees in the Early Holocene/Mesolithic period. The pollen assemblages are dominated by arboreal (tree) taxa and are represented by Pinus (pine), Corylus (hazel), Quercus (oak), Ulmus (elm), Salix (willow), Betula (birch), with Pinus and Corylus having the highest representation pointing to the presence of many trees and shrubs in the locality. Wood samples from the tunnel area were identified as pine, hazel, alder and oak. Herbaceous and grassland pollen which are indicative of pasture are very low. However, some Poaceae (grasses) were recorded, all be it at low levels, in some of the samples suggesting that there was some open area or grasses growing close by the tunnelling works. While the environmental evidence is suggestive of an environment that could support the presence of man, no physical evidence has been found to support this theory (O’Carroll 2013).

The results of detailed environmental analyses demonstrate a woodland landscape dominated by pine and hazel trees. The positive identification of alder wood remains and the early date of cal BC 7847- 7595 provides direct evidence that alder trees had reached the west of Ireland earlier than was previously thought.

Reference:

O’Carroll, E. (2013) 'Preliminary report on environmental samples from Sruwaddacon Bay, Co. Mayo.' Unpublished report on behalf of Courtney Derry Heritage Consultancy. 

c/o Courtney Deery Heritage Consultancy Ltd. Lynwood House, Ballinteer Road, Dublin 16.