2018:671 - Palmerstown, Johnstown, Kildare

The excavation of an early medieval enclosure with prehistoric habitation activity was undertaken following a geophysical survey (18R0006) and test-excavations (18E0040). This D-shaped enclosure measured 42m north-west/south-east by 32m internally with a straight portion along the north-eastern section and no evidence for an entrance causeway. The enclosure ditch varied from 2.2-3.1m in width, had a length of 137m, averaged 0.95m in depth with a maximum depth of 1.65m. A series of pits, post-holes, ditches and slot trenches were excavated within the interior of the enclosure and several phases of activity were identified. Charcoal retrieved from a basal fill of the straight, north-eastern part of the enclosure ditch was dated to AD 689-878 (D-AMS035142; 1234 +/- 24 BP) while more charcoal from a middle fill of the south-eastern arc of the enclosure ditch produced a similar date of AD 680-879 (D-AMS035449; 1247 +/- 26 BP). The corroded iron objects such as the nails and a Cu-alloy pin shaft collected from the enclosure ditch are further evidence for the early medieval date of this site.

Prehistoric
A slot trench in the northern portion of the interior produced numerous Early Bronze Age Vase tradition pottery sherds, flint flakes and debitage. The slot trench was U-shaped in plan, 15.75m in length, 0.51-1.14m in width and 0.24-0.52m in depth with an internal diameter of c. 6.4m. This indicated the remains of a structure, possibly a house, though possibly also a less substantial structure like a workshop or simple wind-break.
It was truncated by another slot trench, semi-circular in plan measuring 9.6m in length, 0.16-0.7m in width and 0.15-0.25m in depth with internal diameter of c. 6m while the northern arc was truncated by a later linear feature.
A third slot trench lay c. 8.5m to the south-east. This short curvilinear feature had a length of 4.12m, width of 0.22-0.25m and depth of 0.08-0.1m and its only fill contained a single flint flake. This slot trench was truncated by a pit containing a charcoal-stained fill with heat-affected stones and appears to represent a roasting pit. A series of other pits with similar fills were identified within the enclosure and may be roughly contemporary. Containing similar heat-affected stones in their fills were a cluster of larger pits in the eastern part of the site.

Late Medieval
A shallow pit measuring 2.9m north-west/south-east by 2.1m by 0.1m in depth contained numerous Dublin-type ware (13th-century) green glazed pottery sherds in its single fill. This shallow pit abutted another pit and was surrounded by numerous other features, e.g. a slot trench and possible roasting pits of probable prehistoric date and other undated ditches. Numerous Dublin-type ware (13th century) and Dublin-type fine-ware (late 13th-14th century) sherds were retrieved from the top fill of the enclosure ditch.

Post-medieval/early modern
A ditch marked on the 1st edition OS map was identified orientated along the straight portion of the enclosure ditch to the north-east. A recut, visible in the fills of the enclosure ditch in a section, was aligned with this ditch suggesting that the straight portion of the enclosure ditch was utilised as the field boundary marked on the 1st edition OS map.
A series of north-west/south-east running plough/cultivation furrows traversed the excavation area. They were generally evenly spaced, around 2m apart, and produced mostly modern finds of glazed pottery, glass and iron fragments.
The upper fill of the enclosure ditch also produced modern finds like glazed pottery, glass and iron fragments. Rather than the enclosure ditch being open in the modern period and accumulating this debris it is thought that these artifacts were introduced into the top fill by the action of ploughing represented by the cultivation furrows.

Archer Heritage Planning, 8 Beat Centre, Stephenstown, Balbriggan, Co. Dublin.