A vanishing medieval church site on Ireland’s Atlantic coast 181
Fig. 4—Staad Abbey, Co. Sligo, February 2015. Note the scoured nature of the section face and the mass of seaweed deposited by storms; compare with Fig. 2 (photograph courtesy of Ciaran Davis).
themselves to monitoring the site and periodically resurveying the cliff edge (Table 1).This present paper incorporates results up to the most recent resurvey, in March 2020.
The study has incorporated both existing and new sources of information and the methodology has been adapted as new technologies have become available. The initial desk-based assessment of existing data relied on the first (1837) and third (1940s) editions of the Ordnance Survey six-inch maps and the 25-inch map (1910). To this were added scanned images of the tripod-mounted EDM surveys of the cliff edge and church made by Bentley and McCormick in 1993 and again by McCormick and O’Sullivan in 2000 and 2001.The site was resurveyed in 2012 and 2014 by the present writers, again using a tripod-mounted EDM. The year 2016 saw the production of high-resolution ortho-rectified aerial photography and, importantly, the production of a three-dimensional digital surface model, using a drone operated by Paul Naessens of Western Aerial Survey.This captured a detailed view of the cliff edge and church, and also of the topography of the land. Finally, in 2020 the cliff edge was assessed using survey-grade GPS. Results were processed using ArcGIS 10.6. For the historic maps and the earlier surveys, results were based on aligning the depicted walls of the chapel and then using this to recreate the cliff edge at that point in time. By contrast, results from
2012 onwards were digitally recorded and the data have been incorporated into the ArcGIS database.
Coastal environments are not static. They are complex, non-linear dynamic systems, with continual movement of stones, sand and vegetation, and both net deposition and net erosion can occur (Woodroffe 2007). The section face in the cliff at Staad is periodically revealed and concealed by natural events. Repeated visits to the site over almost 30 years have found it either obscured by slumped material sprouting new grass or freshly scoured by the sea, fully exposing the archaeological stratigraphy (compare Figs 2 and 4). The souterrain and lime clamp were large, distinctive features and provide good examples of how much damage is occurring. As first identified in 2000, the lime clamp was a large, bowl-shaped pit lined with stone (Fig. 5). There were burnt sediments in the fills, and the sides were scorched by the heat that is generated when roasted crushed limestone is slaked in water to make lime putty for construction work. In 2005 and 2007 the clamp was still recognisable and largely intact. In 2012 it was partly obscured by grassy sod formed on slumped soils. By September 2014 the section face had been scoured clean by the sea and only a few of the side stones and some dark fill remained. By 2016 the feature was only visible as an area of dark soil containing a bed of heat-fired clay, and by 2020 it had entirely eroded away.The souterrain followed a similar
