2017:039 - A6 Dualling Randalstown to Castledawson (Hand Augers), Derry

BACKGROUND

The purpose of the hand auger survey and assessment was to identify areas of higher archaeological potential within peaty deposits that overlay alluvium. Areas of higher potential would typically be represented by buried archaeological remains, find spots, and zones of palaeoenvironmental interest (including buried land surfaces) where thick and well-stratified deposits of organic/inorganic sediment survive. Hand auguring was required in three areas (detailed below) within Zone 1 of the Road Scheme as the peat deposits here were too soft to allow for safe mechanical test trenching. Manual hand auguring was deemed the only viable method of archaeological site investigation which could be undertaken.

At Hillhead Road there were two areas where a hand auger survey was required (Area A and Area B). These areas were close to a site recorded as a crannog (LDY 045:44). No archaeological remains were found during the mechanical test trenching undertaken immediately south of these Areas. Previous ground investigation (GI) work close to Area A (borehole CTP032) had identified peaty layers interleaved with layers of alluvium, to a combined depth of at least 3m, and localised made ground deposits further to the south (former landfill). Area B was also located at Hillhead Road, but to the east of the putative crannog site. GI investigations in this area (CTP107) had indicated sandy silt and peat to a depth of 1.6m (interpreted as made ground) overlying alluvium which is at least 2.9m thick.

The third area for hand auger survey (Area C) was located to the west of Deerpark Road, in an area that was until recently covered by a dense impenetrable sward of bushes and trees. GI investigations across Area C have indicated a sequence of peat ranging from 0.1m thickness to 0.8m, overlying thick deposits of alluvium to depths of over 3.5m.

LOCATION INFORMATION

The central points of each area were:

Area A: H 94706 92697 (ITM X 694649 Y 892707)

Area B: H 94942 92793 (ITM X 694884 Y 892803)

Area C: H 95924 92866 (ITM X 695866 Y 892876)

RESULTS

The peat was a maximum depth of 1.2m in Area A, 1.45m in Area B and 1.1m in Area C. There was no evidence of archaeological remains in any of the augers from these three areas. Area A had peat deposits overlying a single flooding event which overlay an earlier band of peat which in turn lay on lake bed deposits. Area B had peat deposits overlying two flooding events, with thin peat growth occurring inbetween these phases, the first peat deposit lay on lake bed deposits. Area C provided evidence for deep peat deposits overlying a flood event, which in turn overlay lake deposits Organic-rich sediments were identified in each area, which is not unexpected given the maritime temperate climate of Northern Ireland and any of the investigated areas could provide a palaeoenvironmental story. However, as no archaeological site was encountered within the vested boundary of the road scheme, and in close proximity to this environmental study, it was not deemed appropriate that further detailed environmental reconstructions be undertaken in these areas.

NAC, Farset Enterprise Park, 638 Springfield Road, Belfast, BT12 7DY