2012:195 - Deanestown and Sheephill, Dublin

A geophysical survey was undertaken of development lands within the National Sports Campus, Abbotstown, Co. Dublin by Minerex Geophysic Ltd (Detection Licence No. 12E0111). This survey identified a series of anomalies indicative of sub-surface features of archaeological potential. A programme of test trenching was then recommended. The trenches were designed with the primary aim of testing the geophysical anomalies present at the site.

A total of 13 trenches (770 linear metres) were excavated and several areas of archaeological significance were identified, which largely corresponded with the results of the geophysical survey. This material was mostly concentrated in the south of the proposed development area and within this concentration three main areas of archaeology are distinguishable comprising a burnt mound, a brick production site and a series of medieval ditches. Several undated and post-medieval linear features were also identified throughout the tested area.

Burnt Mound

A square area of high magnetic response in the east of the area intersected Trench 1. A burnt mound was identified in this trench and two further perpendicular trenches were excavated in order to determine its north–south extent. The burnt mound deposit consisted of heat-shattered stone and charcoal in a matrix of silty clay which measured 8m north-east/south-west by 4m and 0.25m deep where tested. Overlying the burnt mound was a deposit of orange oxidised material which measured 1.2m by 0.9m and 0.13m deep. This may indicate a hearth location associated with the burnt mound or may represent later burning at this location.

The natural subsoil in Trench 1 was found to slope down to the south-west from the location of the mound before rising again after approximately 3m. A layer of grey marl was identified in this depression and is thought to represent the natural infilling of a former stream channel. The location of the burnt mound may therefore have originally been at the edge of a stream.

Ditch complex

A series of linear features were identified in Trenches 2-7 that largely corresponded to linear anomalies evident in the geophysical survey results. A number of the features contained medieval pottery and so it is certain that these are of medieval date. In some cases they seem to be interconnecting to form square or rectilinear spaces, which suggest some level of organised settlement activity.

However, a number of the linear features identified were post-medieval in date and represent later patterns of division and drainage. A double ditch feature evident in both the geophysical survey and testing results is likely to represent a field boundary that appears on the 1st edition OS map. A live culvert was also encountered which is believed to contain a tributary of the river Tolka that appears on early maps such as Rocque’s map of county Dublin (1756) but which had been culverted by the time of the 1^st edition OS survey. The palaeochannel encountered in Trench 1 is believed also to relate to this watercourse.

Brick clamp

Trenches 7, 7a and 7b were excavated to investigate a strong geophysical survey response. The response was found to derive from deposits of red brick. The main concentration of the brick was located in Trench 7b where a dense deposit of broken and burnt brick fragments was found to measure 5.55m wide and 0.28m deep where tested. This activity is characteristic of brick-production and, notably, the 1^st edition OS map labels the north end of this field as ‘Brick Field’.

Rubicon Heritage Services Ltd, Unit 2, Europa Enterprise Park, Midleton, Co. Cork