2023:871 - Capdoo and Capdoo Commons, Kildare

A pre-planning enquiry relating to the development of a landscaped park was submitted to the National Monuments Service, Dept. of Housing, Local Government and Heritage to determine what requirements the Department might have with respect to Archaeological Heritage. The response from NMS included a recommendation that the development should be subject to an Archaeological Impact Assessment (AIA) and that the “AIA should involve licensed archaeological geophysical survey in the first instance in order to assist in characterising the baseline archaeological environment of the proposed site. Thereafter, a detailed design should take cognisance of any anomalies identified in the geophysical survey that may represent sub-surface archaeological features/deposits. In consultation with the Department and based on the results of geophysical survey and review of a detailed design, targeted Archaeological Test Excavation may be required thereafter to fully inform the AIA”.

The site was subjected to a Geophysical (Gradiometer) Survey undertaken by J.M. Leigh Surveys Ltd in April 2023 (Licence Ref: 23R0158). A number of anomalies of geological and potential archaeological interest were uncovered, including a possible enclosure feature.

A phased programme of Archaeological Testing was undertaken in July and September 2023. The primary aim of such testing was to determine the archaeological nature of the specific anomalies detected by the geophysical survey, as well as to get a better understanding of the broader background geophysical responses.

The results from the programme of Archaeological Testing indicate that the anomalies detected by the Geophysical Survey were, for the most part, associated with modern agricultural ploughing practices or geologically-derived variations on the subsoil, including former alluvial actions associated with the River Liffey. In particular, Anomalies 2 and 3, determined to be possible ‘burnt spreads’ by the geophysical survey, proved to be associated with naturally occurring iron panning; the broad amorphous responses (Anomalies 7 and 11) are associated with geological alluvial actions, with Anomaly 16 (curvilinear trend) and miscellaneous magnetic anomalies associated with buried modern ferrous material. A number of the linear and other similar geophysical anomalies, including Anomalies 8 and 12, appear to be associated with ploughing, compacted ‘rut marks’ associated with harvesting vehicles or former ploughed-out drains. No evidence for possible pits (Anomalies 4, 6 and 9) was uncovered by the programme of intrusive testing; in that regard, it is noted that a pit uncovered in T14, considered to be of archaeological interest, was not detected by the geophysical survey.  Anomaly 15 (parallel trends) are associated with variations in the subsoil, most likely with respect to geological alluvial activities associated with the formation of the river channel; likewise, the possible enclosure feature (Anomaly 13) appears to be associated with similar geological alluvial activities at the base of a small area of raised ground/hillock; deeper depths of topsoil at the base of such raised ground, formed by ‘soil creep’, may also be responsible for the geophysical responses in the southernmost area of the survey.