1993:198 - ARDREA LOUGH, Sligo

An excavation on the eastern shore of Ardrea Lough was carried out by the Irish Archaeological Wetland Unit between 4th and 15th October 1993. Extensive reclamation of the eastern shore had resulted in the disturbance of at least one archaeological monument and large quantities of archaeological material had been noted along the reclaimed area. The reclamation was ongoing and so the principal function of the excavation was to establish the extent of disturbance and discover if any remaining intact archaeological deposits were immediately threatened.

The excavation was carried out in two phases. The first involved a detailed survey of the lake-shore area. The area of disturbance was field-walked on a metre by metre basis and surviving archaeological material was recovered. Metre square test pits were also dug along the line of disturbance. These were spaced some 10m apart and extended along the shoreline for some 180m. The second phase of the excavation concentrated in one particular area of disturbance. The topography of this area was slightly higher than the surrounding shore and had resulted in a small protrusion into the lake. A particularly dense concentration of disturbed archaeological deposits had been recovered here and a more detailed excavation was carried out in a 15m x 4m area.

The initial field-walking produced varying amount of archaeological material, all of which had been badly disturbed and appeared to have come from either the immediate shore-line or the lake-bed. Wood and animal bone made up the vast bulk of this material. The volume of animal bone was quite large, considering the amount of disturbance. Several other finds were recorded, all in disturbed contexts. These included several wooden staves, iron and stone objects, and part of at least three rotary querns. Two of the latter had been found by the landowner prior to the excavation.

The test pits indicated that there was no significant archaeological material in the upper 1.5m of the current shore area. In one or two instances, particularly to the south of the excavated area, a number of posts were recorded. These were found in isolated contexts deep in old lake-shore deposits.

The excavated area revealed an upper level of disturbed material, primarily fragmented wood and animal bone. Several of the wood pieces had been worked but few remained intact. The majority of the timbers were oak (80%) but ash and birch were also present. Removal of this upper disturbed material revealed the limit of the old shore-line. This level was marked by a dense layer of sod, primarily reed and lake-sedge. Beneath this sod layer were various lake deposits and successive old shore-lines which indicated that the depth of the lake varied considerably in the past. The only significant archaeological material which remained in situ was a series of posts which were located in the south-west of the cutting, some 0.45m below the current upper surface. There were approximately 18 of these posts, which varied from 0.1m to 0.21m in diameter. Several posts appeared to form an arc which curved back towards the lake. The majority were oak with just a single ash example. These posts were sufficiently below the level of possible further reclamation and were not investigated further.

The results from Ardrea Lough indicate that at least one major monument had been badly disturbed by the reclamation of the shore-line. The location of the posts may indicate that this monument was located close to shore in the area of the cutting. The immediate area of the lake was examined by diving but no archaeological structures or material was apparent. It would appear that the majority of the disturbed structure was underwater and had been disturbed by dragging up the lake-bed to form a new shore-line. Considering the amount of previous disturbance, the only possible remaining structure which could be damaged further was in the area of the posts.