2000:0828 - DERRYNAGUN BOG, Lemanaghan, Offaly

This excavation was carried out in Derrynagun Bog, Co. Offaly, as part of the 2000 Bord na Móna Archaeological Mitigation Project. Two stake rows were identified during the 1998 IAWU reassessment survey in Derrynagun Bog, Co. Offaly. 98DNG 0008a–b consisted of two sightings 30m apart that were in line with 98DNG 0048a, which was 30m south of 98DNG 0008b. The sites were recorded as stake rows because all of the elements exposed in the 1998 survey were small, upright brushwood rods. Excavation this season proved inconclusive because the sightings were so fragmentary. However, it is possible that these may be the last remains of either small brushwood platforms or toghers. The mitigation strategy document prepared by Dúchas The Heritage Service and the National Museum recommended that the extent of these sites be traced, surveyed and sampled. It was recommended that a number of the stakes be investigated to establish the relationship between them and to check for possible associated features between them. Three small cuttings were excavated, as well as several slot-trenches between the known sightings. The first of these cuttings, Cutting 1, was placed at 98DNG 0048a, while Cuttings 3 and 4 were placed at 98DNG 0008a and 0008b respectively.

The first cutting was located alongside the drain edge at the site identified as 98DNG 0048a. An area measuring 1.8m x 1m was trowelled at this location, and a maximum of 20–40mm of peat was removed. This peat was very dried out and contained a large amount of fibrous matter, the majority of which was ericaceous roots that were most likely from the recent plant cover. In addition to the original three to four stakes recorded in 1998, a further eleven brushwood rods were exposed. Most of these were irregularly placed, some in semi-upright positions. The brushwood elements ranged from 6mm to 24mm in diameter, and none was over 0.26m in length. The peat into which these elements were set was slightly greenish in colour and pasty in texture. Directly alongside the wood, the peat had a high eriophorum content, while the remainder of the cutting was high in sphagnum.

The second cutting was also placed directly at the location investigated in 1998 (98DNG 0008b), at which time eleven small stakes were identified. As with the first cutting, the upper peat was very dried out and consisted of sphagnum-rich peat with a large amount of modern fibrous matter inclusions, mainly ericaceous roots. An area measuring 1.3m x 1.4m was trowelled and revealed that only three of the original eleven posts remained in situ. These ranged from 16mm to 19mm in diameter and from 0.28m to 0.31m in length. Two of the posts had simple, single-faceted, chisel-point toolmarks. The peat into which these posts were set was mottled in appearance. It was all sphagnum-rich, the darker peat having a pasty texture.

The final cutting was located at the sighting recorded in 1998 as 98DNG 0008a. Five of the small stakes were visible through the shallow peat cover. This was similar to the peat exposed in Cutting 2. Eight upright stakes were revealed after the removal of this upper peat. These were set at angles of 45–85° and varied in diameter from 12mm to 17mm. There were some dried-out brushwood fragments with no discernible context scattered around the area of the cutting. The peat into which the stakes were set was also similar to that in Cutting 2. It was mottled in appearance but was also very dried out, with several large cracks in places. This last cutting was extended, and several slot-trenches were also investigated on the adjoining fields between the cuttings, but no additional trace of the site was found.

There are several enigmatic sites within this particular zone of activity in Derrynagun Bog. Where there was more peat cover over Cuttings 2 and 3, there was a small amount of additional brushwood rods noted. These were very fragmentary in nature but may mean that these sites represent the last remains of another site type altogether. While they may have formed part of a linear togher running east–west across the bog, they may also be similar to the small platform-like structures that were excavated by Ellen OCarroll this season (see Excavations 2000, Nos 820–6 and Excavations 2000, Nos 833–6).

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