ANTIQUITY, XLV, 1971 New radiocarbon dates from Ireland A. G. SMITH, J. R. PILCHER and G. W. PEARSON Dr A. G. Smith is one of the Directors of the Palaeoecology Laboratory of Queen’s University, Belfast. A great part of the work of the Belfast radiocarbon dating laboratory, which is in the charge of MY G. W. Pearson, has so f a r been connected with environmental studies. A number of dates have been obtained, however, from archaeological contexts. In this article, written with two colleagues in the Laboratory, the archaeological dates are summarized and an outline given of thepalaeoecological work in a more reasoned and coherentform than the published date lists (Smith, Pearson and Pilcher, I970; and forthcoming). Many of the archaeological samples dated have been charcoal.* This has been most rigorously pre-treated to remove contamination by rootlets and humic material. The dates have been obtained by gas-proportional counting of methane. The results are reported as con- ventional radiocarbon dates using the 5570 year half-life. NEOLITHIC SITES The oldest dates obtained, so far, are from a series from A. M. ApSimon’s excavations at Ballynagilly Td., Co. Tyrone (ApSimon, 1969a). The dates are: 3675 f 50 bct (UB-197) from charcoal in a pit containing hearth debris and sherds of Neolithic pottery a few metres away from the Neolithic rectangular house. Secondly, 3795 f 90 bc (UB-~O~), from charcoal in a hearth in the Neolithic occupation area. Thirdly, 3690 f 90 bc (UB-307) from charcoal in a pit with early Neolithic pottery, sealed by sterile sand. These dates, whose means fall between 3700 and 3800 bc, are older than any so *We should like to thank our colleagues who have cooperated in providing well-documented material for dating and in discussing with us the significance of the results. In particular we thank Mr A. M. ApSimon who has read the manuscript and made valuable suggestions. tFollowing the lead of Suess and Strahm (Antiquity, XLIV, 93) we have adopted Dr D. Shove’s suggestion of denoting conventional radiocarbon ages on the Christian calendar scale by lower case letters. 97 far obtained for Neolithic material in the British Isles. Nevertheless, they form a consistent group and it will be of great interest to see whether dates in this range are obtained from other sites. Meanwhile, it is worthy of mention that in the Lower Bann Valley, at Ballyscullion, the later part of a brief phase of forest clearance dis- tinguished in a detailed pollen diagram (Smith and Crowder, unpublished) has been dated by radiocarbon to 3580 f 60 bc (UB-116). This clearance took place several centuries before the landnam clearance usually associated with the Early Neolithic and dated at the same site to 3180 f 60 bc (UB-115). A landnam phase has also been discovered at the Ballynagilly site. The beginning of the clearance, at a level where pine charcoal is present and the pine pollen curve declines, has been dated to 3195 f 70 bc (UB-253). I n another part of the site, oak charcoal stratified into peat deposits, at a level of a decline of oak pollen, has been dated to 3245 f 60 bc (UB-15). Hazel charcoal under a layer of re-deposited sand has been dated to 3345 f 90 bc (UB-18). It seems clear that the forest clearance was the work of builders of the rectangular house. The charred remains of the split-oak planking forming the walls of this house have been dated to 3215 & 50 bc (UB-201) and charcoal from a posthole inside the house to 3280 f 125 bc Other dates from Neolithic contexts at (UB-199).