2000:0809 - KILLAUN BOG, Clonbeale More, Offaly

This excavation formed part of the process of the mitigation of archaeological sites in the industrial peatland of Killaun Bog, Co. Offaly, where sites were already known to exist. This work was carried out on behalf of Dúchas The Heritage Service by ADS Ltd. This report details the excavation of the sites 98CBM 0014 and 0015, initially recorded as two separate roundwood and brushwood structures (IAWU 1998). Excavation revealed that there were, in fact, three small structures within a 6m length of drain face. Killaun Bog is 5km east of Birr along the road to Rath village. This bog is not, as yet, in full peat production.

A single 6m x 2m cutting was placed on the field surface above a 5m spread of archaeological material exposed in section in the drain face. This spread appeared to be arranged in three distinct groups. The north-western extent of the spread was a small area of brushwood 1.2m wide. This material was located 0.45m from the field surface and was two to three brushwood rods deep. It is described below as Site A. The central group of material was composed of six roundwoods contained within an area 0.8m wide and was recorded during the excavation as Site B. The third site was smaller, consisting of a single machine-damaged timber exposed in the drain face, and was recorded as Site C.

Site A was a small brushwood site at the north-western extent of the cutting. The peat over this site was rich in undecomposed sphagnum and ranged from bright yellow to orange in colour. The site was exposed just inside the western cutting edge. It was 0.4–0.6m below the field surface and only 0.15m above the water level in the drain. It was composed of both longitudinal and transverse brushwood elements. The whole site was only 1.2m x 1.6m in size. The elements ranged in diameter from 7mm to 52mm. The larger elements were transversely laid, 0.35–0.45m apart, with the smaller rods laid longitudinally. While the site initially had a hurdle-like appearance, the transverse elements all overlay the longitudinals. Not all of the longitudinal elements were completely intact, however, and it is possible that they may have broken off where they once lay across the transverses. The whole structure was two to three rods deep. A cutting edge was removed to establish if the site continued westwards, but it appears that the material exposed within the cutting made up the site as a whole. This site may have been a small hurdle panel thrown down over an area of localised wetness or may have been associated with the construction of the brushwood and roundwood togher 00E0242 (Cutting 3), see Excavations 2000, No. 808, which was located 15m to the east of this excavation cutting.

Site B was 1.7m east of Site A. Six roundwoods were exposed in the drain face contained within an area 0.8m wide, 0.5m deep and 0.34m below the field surface. This site appeared to be that recorded in 1998 as 98CBM 0014. The peat directly over this site was different to that over Site A. Beneath the top 0.32m of undecomposed sphagnum peat was a narrow band of greyish, pasty, well-decomposed sphagnum peat that overlay the darker peat containing the site. This darker peat was moderately well decomposed and contained inclusions of heather roots and eriophorum. The site was composed of six roundwoods exposed close to the drain edge, with a fragment of a seventh roundwood to the south. There were four roundwoods lying in a north-east/south-west direction, with a single roundwood transversely laid between them. There was a sixth roundwood 0.14m below these ‘upper’ elements. This was running east–west but may have been disturbed by the cutting of the drain. This whole site was encompassed within an area measuring 0.75m x 0.85m and 0.5m in depth. The fragmentary nature of the feature may be the result of a site that was displaced by the drain cutting. Each element was sampled for wood species identification, and dating and environmental samples were taken.

Site C was the most fragmentary of the three sites. It was located at the eastern extent of the cutting and 1.59m east of Site B. The peat over this site was the same as that over Site B. Beneath the top layer of undecomposed sphagnum peat was the narrow band of greyish, pasty, well-decomposed sphagnum peat that overlay the darker peat containing the site. This darker peat, as before, was moderately well decomposed and contained inclusions of heather roots and eriophorum.

This site was composed of a longitudinal oak plank fragment set with two damaged brushwoods alongside it, all running in a north-east/south-west direction. There was also an upright oak plank at an angle of 70° at the drain edge. The site was 0.7m wide, 0.65m long (max.) and 0.4m deep. The function of this site is unclear. The fragmentary nature of the excavated remains suggests that these elements may be displaced or may be waste material from a more substantial site.

It is possible that all three of these small sites may be associated with No. 808 Excavations 2000, 00E0242, (Cutting 3), which was located 15m east of this excavation. 00E0242 was exposed in section at fourteen locations across the bog. At many of these sightings this togher was deceptively wide where the mechanical cutting had spread pieces of wood along the drain faces. The apparent lack of structure to Sites B and C could therefore be explained as waste material from the construction of the larger togher, while Site A appears to be more like the small platform structures excavated elsewhere in County Offaly.

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