2010:506 - Slievemore, Achill Island, Mayo

NMI Burial Excavation Records

County: Mayo Site name: Slievemore, Achill Island

Sites and Monuments Record No.: N/A Licence number: 09E0301 ext.

Author: Stuart Rathbone, Achill Field School, Dooagh, Achill Island, Co. Mayo.

Site type: Bronze Age round house

ITM: E 463051m, N 807587m

Latitude, Longitude (decimal degrees): 53.999341, -10.088897

Round house 2 is a large and complex building located on the southern side of Slievemore approximately 45m east of the very similar Round house 1 that was excavated by Simon Ó Faoláin, Ros Ó Maoldúin and Stuart Rathbone of Achill Field School between 2006 and 2008 (Excavations 2006, No. 1471, 06E0428; Excavations 2007, No. 1246, 07E0191; Excavations 2008, No. 928, 08E0578). Excavations by Teresa Bolger of Achill Field School began at Round house 2 in 2009 when four trenches were excavated in a cross-shaped pattern centred on the middle of the building (Excavations 2009, No. 625). In 2010, excavations were continued at the site extending two of last year’s trenches and opening two new trenches to the west of the building.

At the east of the structure Trench 2 was expanded greatly to fully expose the entrance feature and the eastern outer face of the building. This revealed the true scale of the building, in particular the massive size of the walls and the full length of the entrance passage that runs through them. In 2009, a crude upper level of pavement was recorded in the entrance and where a small piece of this was removed a much neater earlier pavement was observed. In 2010, this early pavement was fully exposed throughout most of the entrance and was found to consist of large flat stone slabs sitting on a foundation layer of small rounded stones. To the south of the entrance a field wall was found to attach to the outer wall of the building which had a width in excess of 2m. The junction between the wall and the building was very neat, suggesting the wall and the building are closely contemporary. The line of this wall was subsequently traced for 58m out to the south-east. To the north of the entrance several very large angular boulders were found lying on the surface of the mineral soil immediately outside the building. These are tentatively identified as part of a second field wall and bog probing suggests it continues for some distance to the north-east of the building. However, bog probing is difficult on Slievemore as the ground surface below the peat is highly irregular and contains large natural boulders and its existence will only be proved through further excavation.

At the south of the structure, the southern end of Trench 3 was extended by several metres in order to investigate a complex deposit of stone that was located in 2009 but not fully understood given the small area examined. Trench 3 was extended to give a total length of 10m. The previously observed stone deposit was found to be the edge of a large field wall running in a south-west direction from the southern edge of the building. This wall was quite unlike that found in Trench 2 and consisted of a row of very large elongated boulders resting on top of a mass of medium-sized stones. Clearly the wall was in a collapsed state but it is thought most likely the large boulders had originally stood upright on their short ends. The area where the wall connected to the walls of the building was unfortunately just outside the eastern limit of the trench, although the way in which the collapsed wall rises up to meet the building suggests that the wall was built after the structure.

Three new trenches were excavated at the west of the building to examine the continuation of a possible field wall that had been observed in the northern side of Trench 4 during 2009. Trench 5 measured 10m by 2m and ran approximately east–west. No archaeological deposits were discovered highlighting the difficulty of bog probing on Slievemore as the trench was set out over where bog probing had suggested the line of the field wall ran. Two further trenches were subsequently excavated at right angles to the first to form a cross pattern. In the southern Trench 6 again no archaeological deposits were discovered but at the far north of the northern Trench 7 a concentration of large angular boulders was discovered that is thought to have been part of the wall found in the northern side of Trench 4. Consisting of a row of medium and large boulders, the field wall at the west of the building has more in common with the walls in the north-east of Trench 2 and running along Trench 3 rather than the wall discovered in the south of Trench 2.

As with the excavations in 2009 artifacts were limited to a small number of pieces of flint and a large assemblage of fragmented quartz pieces. Samples taken from the central hearth in 2009 have now been processed and charcoal was identified from seven different deciduous species (alder, birch, elder, hazel, holly, oak and willow) indicating a healthy deciduous woodland in the locality. Carbonised pieces of Calluna (ling heather) from the same sample indicate bogland was also present, possibly on the higher parts of the mountain. A date of 1431 to 1314 cal. bc (2 sigma) was obtained from a piece of the heather indicating a date of occupation in the Middle Bronze Age. A sample from the central hearth in Round house 1 was also processed and six deciduous species (alder, birch, blackthorn hazel, holly and oak) were identified. A sample of Corylus (hazel) returned a date of 1296–1115 cal. bc (2 sigma), again in the Middle Bronze Age.