Habitation site in Cill Mhuirbhigh

During the course of research excavations in Dún Aonghasa (GA110-039----) this bedrock hollow, identified as F1002, was exposed at the N end of Cutting 1 in the inner enclosure. It consisted of a large irregular L-shaped hollow (max. dims. 9m E-W; 7.6m N-S; D 0.12m) that was broadest at its N end where it disappeared under the wall terrace of the enclosure. The feature was a natural depression but it had been enlarged. An E-W horizontal break in stratigraphy was evident midway along the length of its primary phase. A large hearth occupied most of its N half. Initially this part of the hollow was cleaned out and enlarged, and then a dump of beach sand (D 0.14m) was spread over an area of 9m by 1.8m. Within this area, the lower horizon of the hearth (diam. 1.52m) was defined by sand that was stained to a dark grey or black colour and had an abundance of charcoal. No built features were associated with it. Artefacts recovered were mainly found along its perimeter from S to SW, suggesting a pattern of discard or loss. They included pottery, a complete bone pin, a pin shank, a bone point, two fragments of pumice and some worked chert. Two concentrations of limpet shells were also uncovered, one extending off the hearth at SW, the other a short distance to its ESE. Two almost complete scallop shells and fragments of others were also found on the margins this level. The dumping of another substantial layer of beach sand (D 0.1m) over the hearth and the hard surfacing of the surrounding area marked the interface between this lower horizon and the upper ones. The later hearth was defined by a spread of charcoal and ash (3.8m x 1.8m; D 0.1m). At this level the fill contained a small amount of animal bone, shattered fragments of granite and a few sherds of unburnt pottery. Above this level the fill consisted of charcoal, grey ash and oxidised clay mixed with sand. A sample of the charcoal yielded a radiocarbon date of 1070-800 cal. BC. Almost 8.8kg of animal bone was recovered from the fill, only a few showed any traces of burning. A sample of unburnt animal bone from the surface of the hearth at its W edge yielded a radiocarbon date of 920-510 cal. BC. This probably marked the abandonment or immediate post-abandonment phase of the hearth. In addition, finds included pottery, a clay mould core, three bone points, cobble tools and a piece of worked pumice; none showed any trace of burning. The hard surfacing around the hearth consisted of a haphazardly paved area to its E, S and SW with a line of more regularly laid slabs forming a kerb-like feature along its S and SW edges. There was also a cobbled surface to its N. In occupation-derived deposits that built up over the paving to the E of the hearth, ten clay mould fragments were found, seven of which were for casting pins; one was part of a mould gate. Two more moulds for casting pins were found adjacent to these and three were recovered to the S of the hearth. Along the N edge another large quantity of animal bone (12.2kg), some fish bones, dispersed limpet and periwinkle shells suggested that this area was mainly used for discarding food refuse. Apart from the clay moulds, some pottery, pumice, bone pins and points, and a needle were found around the margins of the hearth (Cotter 2012, vol. 1, 277-284, 295). The finds indicate that a range of activities was carried out in this area during the Late Bronze Age, varying from domestic to industrial. The mould fragments provide evidence to suggest that bronze-casting, or an episode of it, took place in the immediate area and that the hearth may have functioned as a furnace (ibid., vol. 1, 296; vol. 2, 251-4). The scallop shells further suggest the possibility of ritual activity in this area of the site (ibid., vol. 2, 245). Occupation residues in the S half of the hollow were sparse and the few finds recovered came from the unsealed surface of the layer. They included a fragment of worked pumice, a worked chert flake, some cooking ware and part of a scallop shell (ibid., vol. 1, 278). A cistern or vertical-sided rock-cut pit (1.5m by 1.4m and 0.17 deep) with a flat base was uncovered to the W of the hollow. It was filled with stony clay and was sealed with three flat slabs. It most likely was a water-storage cistern and it may also have had some function related to metal-working (ibid., vol. 1, 282-3, 296). Compiled by: Olive Alcock Date of upload: 22 June 2020