2024:828 - Fassaroe, Wicklow

A programme of testing was undertaken to determine the archaeological nature of anomalies detected by a Geophysical Survey carried out by ACSU (Licence No: 24R0353) within the extent of a proposed LRD (Phase 1) application area, as well as to collate some physical background information concerning the general nature of the archaeological potential of the lands.

A total of twenty-one trenches were excavated by machine fitted with a 1.3m-wide toothless grading bucket, following which the sides and bases of the trenches were visually examined; the positions of the detected geophysical anomalies were further cleaned by hand using a hoe and the resultant spoil was ‘raked-through‘ to increase the chances of artefact recovery. In addition, the upper surfaces of many of the trenches were also excavated to a shallow depth in order to determine, with certainty, that no subsurface features of archaeological interest existed within the areas of testing.

Four trenches were excavated in Field 1. T1 and T2 were positioned to cut through Geophysical Anomalies M1 (a possible sub-circular enclosure), M2 (small to medium sized anomalies – possibly representing pits, posts, spreads, kiln, cut features) and M3 (possible curvilinear ditch); no evidence for any features of archaeological interest were uncovered and it is probable that the geophysical anomalies may relate to deeper geological features or possibly relate to magnetic drift from closely adjacent electrical overhead lines (OHL). T3 was positioned across Geophysical Anomaly M4 (possible linear ditch); no evidence for any feature was uncovered and it is probable that the geophysical anomaly related to a deeper geological feature. T4 was excavated to determine the archaeological nature of Geophysical Anomaly M5 (possible small enclosure); no evidence was uncovered and it is possible that the anomaly relates to deeper geological features or possibly compacted topsoil related to a former circular animal feeder.

T5 was excavated within Field 3 and positioned across a liner feature (former field boundary?) detected by the Geophysical Survey; no evidence for the feature was uncovered and the anomaly related to a variation in the underlying geology. T6 (Field 4) was positioned across two linear anomalies (M7) detected by the Geophysical Survey; naturally occurring variations in the subsoil, comprising bands of gravelly clay, were uncovered in areas coincident with the M7 Anomalies. T7 was also excavated within Field 4 and positioned across a linear anomaly that was considered to represent a former field boundary; a band of concentrated stoney gravelly subsoil was uncovered in the northern area, and generally coincident with the detected Geophysical Anomaly.

Two trenches were excavated within Field 10. T8 was positioned across a Long Curving Geophysical Anomaly (M11); no evidence relating to the anomaly was uncovered ad it is possible that it related to underlying geology or possible magnetic drift from the adjacent electrical substation and/or adjacent OHL. T13 was positioned to investigate two areas of Magnetic Disturbance detected by the Geophysical Survey; the only soil variation was related to soft, damp topsoil associated with a leaking water pipe.

Four trenches (T9 – T12) were excavated in Field 11, where large Ferrous Spreads were detected by the Geophysical Survey. No significant evidence relating to such spreads was uncovered and it is concluded that the detected anomalies relate to adjacent metal mesh fencing and upstanding metal gates forming parts of former animal enclosures.

Two trenches (T14 and T15) were excavated within Field 7, with a further two (T16 and T17) in Field 8, the primary aim of which was to gather some general background information relating to the archaeological potential in such areas; in addition, T14 was positioned to determine if any possible subsurface features related to Geophysical Anomalies (e.g. M10) detected further to the west and outside the extent of the subject Phase 1 Planning Extent. No subsurface features of archaeological interest/potential were uncovered and some variations in the underlying subsoils were noted.

Two trenches were excavated with Field 12. T18 was positioned along a section of a proposed road and across Anomaly M14 (curvilinear feature and possible pits) detected by the Geophysical Survey; the only subsurface feature of note was a band of gravel that was uncovered in the area coincident with Anomaly M14, indicating that it was of natural/geological origin. T19 was positioned through the area of Geophysical Anomaly M15 (possible pits, posts, spreads, kiln or cut features); A grey/black, charcoal-rich deposit was revealed coincident with one of the elements of M15 (ITM: 727929 718172); it measured 0.56m (north-south) x 0.4m, with the eastern edge extending under the eastern trench baulk; the edges were slightly irregular; removal of a stone from the material indicated that the material appears to be a fill of a pit; it was considered prudent not to investigate further as it is likely associated with a more widespread feature, as indicated by the geophysical survey.

Two trenches (T20 and T21) were excavated within Field 13, where probable geological-related anomalies were detected by the Geophysical Survey; these were associated with variations in the underlying subsoil, comprising bands of compact, mid-orange/brown or mid-grey/brown clays, which were generally slightly stoney.

The results of the testing programme will be incorporated in the Cultural Heritage Chapter of the EIAR to accompany the planning submission to the Planning Authority.