County: Offaly Site name: DERRYNAGUN BOG, Lemanaghan
Sites and Monuments Record No.: N/A Licence number: 00E0500
Author: Ellen OCarroll, ADS Ltd.
Site type: Platform - peatland
Period/Dating: Medieval (AD 400-AD 1600)
ITM: E 618286m, N 727309m
Latitude, Longitude (decimal degrees): 53.295767, -7.725691
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 cutting (2m x 2.5m) was found beside a Bord na Móna drain, as the wood could be seen protruding from the drain face. Excavation exposed a brushwood and roundwood platform, one of a series of wooden platforms excavated (see Nos 819–23 above and Nos 825–6 Excavations 2000).
This site had been cut by the drain, leaving only the southern side remaining. Between 0.08m and 0.4m of peat was removed from over the site. The peat layer, which lay directly over the wood, consisted of bright yellow sphagnum peat, which was very poorly humified. Within this peat layer were found Menyanthas trifoliata (bog bean) and reeds, which suggests that there was open water present over the site.
The site was composed of approximately 80 brushwood elements and three roundwoods arranged in a linear fashion. The brushwood ranged from 1.31m to 0.06m in length and from 0.42m to 0.01m in diameter. The roundwood was between 1.2m and 0.65m long and between 0.07m and 0.06m in diameter. The wood was up to three layers deep and was slightly disturbed at the drain edge where the ditcher had cut the drain, pushing the wood together in a haphazard fashion. The area of wood within the cutting was 1.67m wide, although the site’s true width was 0.85m because much of the wood had been disturbed. The site was 2.3m in length, although it was probably slightly longer, as the drain cut the site on its northern side. The depth of the site was 0.43m.
This site may represent a short-lived platform structure used for certain activities that took place out in the centre of the bog. These activities may include hunting wildfowl or gathering a specific organic type of material that grew on the raised bog peat.
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