2000:0820 - DERRYNAGUN BOG, Lemanaghan, Offaly

Excavations were carried out in Derrynagun Bog, Co. Offaly, as part of the Bord na Móna Archaeological Mitigation Project. These excavations were undertaken to resolve known archaeological sites so that Bord na Móna could resume peat production in areas that had been cleared of archaeology. Derrynagun Bog is to the north-east of Lemanaghan dryland island, where the site of the monastic establishment of St Manchan of Liath is reputed to have been founded in the middle of the 7th century. This excavation exposed a brushwood platform, which was one of a series of sites excavated alongside a Bord na Móna drain edge (see Excavations 2000, Nos 819, 821–6). The sites ran from the north-west to the south-east, were all quite similar in construction type and form, and were very close together.

Between 0.01m and 0.3m of peat was removed from over the site, comprising of three layers. Part of the site lay underneath yellow, sphagnum pool peat with inclusions of Menyanthas trifoliata (bog bean). The yellow/orange sphagnum peat and the bog bean indicate that there was an area of open water located over the site. The site was composed of approximately 120 brushwood rods, four roundwoods and some twigs and pegs. The brushwoods ranged in length from 1.14m to 0.09m and averaged 0.02m in diameter. The roundwoods measured between 0.92m and 0.27m in length and averaged 0.06m in diameter. They were arranged in a haphazard fashion, and the wood did not appear to form any coherent structure. A substantial number of pegs were found throughout the structure, particularly at the north-western end of the cutting. The roundwood elements were on the top layer of the structure, while the preponderance of the brushwood appears to lie at the lower levels of the structure. The site measured 4.55m by 3.5m in total area and was 0.47m in depth.

All of the worked ends recorded were chisel-pointed, and some were multi-faceted. There were also some tears noted on the end of some of the brushwood where the branch/stem had been torn from the main trunk. The facets had been cut with a metal axe.

Results here suggest that part of the site was located underneath an open area of water. It is not clear whether the pool was a consequence of the construction of this site or whether the site was a consequence of the pool, and this is an area that needs to be investigated further. It is doubtful that the people who constructed this small platform were covering a very wet area when instead they could walk around the wet pool to avoid it. It is possible that the wood was intended to serve as a small, dry platform for hunting or other such activities; this hopefully will be ascertained through the analysis of the peat and further research into the area during the post-excavation stage.

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