2000:0839 - CORHILL BOG, Lisdermot/Straduff, Offaly

Excavations were carried out in Corhill 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. The field season ran from June to August 2000. This site was excavated at the north-eastern side of Corhill Bog and represented the remains of a linear plank trackway. Subsequent tracing and investigation revealed that the trackway actually crossed the width of the bog as it was also recorded on its south-western side, although no excavations were carried out in that area.

In total, 20m of this trackway was excavated. It was a fairly simple construction comprising a linear plank superstructure laid end to end and then underlain and supported by a roundwood transverse substructure. The substructural transverses supported the plank walkway and elevated it above the wet peat. The superstructural planks were pegged into position through mortices. The trackway was 1m wide and up to 0.25m deep. Two cuttings at the far north-western side of the bog revealed broken oak planks, disturbed pegs and wood chips.

It was clear from these excavations that the trackway was very disturbed at the far north-eastern end of the site, possibly owing to the nature and type of peat on which it was constructed—a fen peat, which is extremely wet. There was evidence for these wet conditions in the form of Menyanthas trifoliata (bog bean), which only grows in open water.

The plank walkway was traced for over 420m, and a record was made at every Bord na Móna drain that bisected the trackway (i.e. every 14m). This site has been dated to 910±9 BC (Q-9292).

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