2014:339 - CLS128, Cloonshannagh, Cloonshannagh Bog, Roscommon

Cloonshannagh Bog is located 3km north-west of Termonbarry and 2.5km west of Lough Forbes. The bog is part of the Bord na Móna Mountdillon Group and has a total area of 331 hectares. A survey by ADS in 2008 under licence 08E0645 identified a total of 88 sites. Upon re-assessment by ADS in 2013 under licence 13E0221 89 sites were recorded. Of the 89 sightings, 60 were platform sightings, 18 sightings were of archaeological wood and 11 were trackway sightings, all of varying lengths and widths. Of these 35 sites were listed for excavation as part of the current contract.

Once the 2013 location of the CLS128 was established using survey-grade GPS equipment the surface area of the bog was cleared in order to try and establish the best location for the proposed cutting. The general area of the site contained evidence of wood (most likely of an archaeological nature) spread across the field surface and as such it was difficult to establish with any certainty what the orientation of the site was prior to excavation. It was located to the south of the recorded sites CLS128b and CLS129 and it was difficult to establish the exact limits of any of these spreads of material. It was decided to open a 4m x 4m cutting around the most dense concentration of material likely to be associated with CLS128a.

The peat above the site consisted of a mid orange-brown sphagnum peat that was poorly humified (H2) with much calluna, sedge, eriophorum and a great deal of menyanthes. It was very compact and laminated.

Site CLS128a was a complex structure, most likely a platform, that was constructed of many different depositions of brushwood and small roundwood material. The primary layer of the lower (substructure) deposits consisted of very densely laid brushwood. These had been laid both east–west and north–south and ranged in size from 0.1–1.31m in length and 0.01–0.04m in diameter. The condition was moderate with most elements fractured along their length, and some were poorly preserved. There were multiple worked ends. This densely pack brushwood layer was overlain by roughly transversely laid roundwoods and heavy brushwoods that possibly represent the main structural component. These had been laid in two layers, and were densely packed with a north-west/south-east orientation. The elements ranged in size from 0.1–1.64m long and 10–100mm in diameter. A series of longitudinal (north-south) roundwoods and large brushwoods were evident laid centrally and along the western limits of the transversely laid layer. They were laid in a linear fashion and ranged in size from 0.34–1.02m long and between 40–110mm in diameter.

A layer of peat was identified overlying the lower elements of the structure outlined above. It was a mid brown-orange pool peat with patches of s. cuspidatum, frequent menyanthes, occasional calluna root, and large patches of dense eriophorum particularly in the north-east corner. The peat was very soft and very well humified (H4-H5).

The upper elements of the overall structure were identified above the C1287 peat layer. Many of them represented small localised deposits of wood/brushwood. The main structure was formed by C1283/C1286, roundwoods and heavy brushwoods, many of which had been damaged by milling on their upper surfaces. They were orientated both north-east/south-west and north-west/south-east and had a moderate density. They ranged in size from 0.19–1.03m long and 0.032–0.068m in diameter. Smaller deposits consisted of patches dense brushwood and may relate to a finer walking surface on the top of the structure. They may have been smaller in area due to being damaged and removed by milling. They were orientated both north–south and east–west and ranged in size from 0.3–0.5m long and 0.01–0.03m in diameter.

The final element of the structure consisted of a series of 28 vertical pegs. These had been driven through the other layers of the overall structure as if to stabilise it. They were moderately to well preserved and ranged in size from 0.27–0.92m long and 20–52mm in diameter.

The peat beneath the site was a well humified (H4-H5) sphagnum-rich pool peat with frequent menyanthes.

An L-shaped slot trench was opened c. 1m to the east of the main cutting. It appeared to have identified the possible termination of the dense C1283 layer, although further wood was evident beneath, possible relating to the substructure elements but this could not be confirmed.

A date of AD 888–1013 was returned from a piece of 5-year-old hazel stake.

IAC Ltd, Unit G1, Network Enterprise Park, Kilcoole, Co. Wicklow