C-14 DATING OF A NEOLITHIC FIELD SYSTEM AT CEIDE FIELDS, COUNTY MAYO,IRELAND

Ceide Fields is a 12 km(2) Neolithic field system in North Mayo in the west of Ireland. The fields, enclosed by an integrated system of ston e walls, have been preserved intact by a cover of blanket bog that is >4 m deep in places. At many locations within this blanket bog the stu mps of ancient pines (Pinus sylvestris) are found in situ. The pine ro ots in most cases are either on the surface of the mineral soil under the peat or at an intermediate level in the pest itself. The age of th e trees in the bog overlying Ceide Fields is therefore of great signif icance for the dating of the fields, as the trees must be younger than the bog in which they are growing, which in turn must be younger than the field system beneath it. We present here the dates (N = 15) for p ine trees from the bogs overlying Ceide Fields and the dates (N = 29) of pine trees from other areas of the North Mayo blanket bog. We compa re these pine dates with published dates of peat associated with a maj or pollen analytical study from within the fields and with published d ates for bog pine from Scotland. The results of the study suggest that the dates for the construction and period of use of Ceide Fields and other Neolithic pre-bog field systems in North Mayo are older than ant icipated and that the date for initiation of blanket bog in many parts of North Mayo is also older than previously estimated. Further, the r ange of dates of the pine stumps indicates a synchronic event contempo rary with a similar phenomenon observed in Scotland.