Crannog

The National Monuments Service's description

Located on a low, natural peat knoll (diam. c. 16m; H above water level 0.5-0.7m) which projects into the Lough More on its SE shoreline. In 1991 drainage works caused the lake levels to drop, and the crannog was exposed to tthe damaging effects of erosion. In 1992 the crannog was surveyed and partly excavated (92E0175) by the Irish Archaeological Wetland Unit (Keane 1995, 167-182). The excavation revealed that a palisade of timber posts encloses an oval area (14.6m N−S; 11.8m E−W) on top of the knoll. The posts form a single line for most of the circuit, but in parts at N−E there is a double or triple row of posts. The majority of the posts are oak and birch, but ash, hazel and willow timbers were also used. The palisade appears to have been constructed to stabilise and define a working area rather than to serve a defensive function. The interior surface was covered by a single layer of stone flags and large pebbles. The density of the layer varied, with gaps evident in some areas, and it is likely that part of the stone surface has been washed away over time by wave action. Large quantities of metalworking debris were found on the stone surface, including iron slag derived from smelting and smithing, fragments of clay furnace linings, and fragments of iron objects. Also found were two stone mortars, and a grinding stone or possible saddle quern. A small assemblage of burnt and unburnt animal bones was recovered, including bones of cattle, horse and pig. A linear setting (L 5m; Wth 1m) of stakes, associated with an unstructured concentration of stones and timbers, extends towards the shore from the E side of the palisade, and was interpreted as a possible causeway. The evidence suggests that the primary function of the crannog was as a metalworking site, rather than as a centre for domestic habitation. A sample from one of the palisade timbers was taken for dendrochronological analysis, and produced an Early Medieval date of 804+/-9 AD. (Keane 1995, 167-182).

Compiled by: Jane O'Shaughnessy

Date of upload: 2 November 2016

References

Keane, M. 1995 The crannóg. In: Moloney et al 1995 Blackwater Survey & Excavations. Artefact deterioration in peatlands. Lough More, Co. Mayo. Irish Archaeological Wetland Unit Transactions: Volume 4, 167-182. Dublin, OPW, UCD.