Radiocarbon Dates Lists 2021

Radiocarbon measurement and calibration data is now producing dates that are of sufficient precision to be of real value in the dating of historic buildings, as an alternative to dendrochronology when this fails to provide a date. The technique is principally being applied through ‘wiggle-matching’ of multiple dates, rather than single sample dates, though the latter can give precise dates under favourable circumstances (e.g. on favourable sections of the calibration curve). The direct result of the wiggle-matched radiocarbon dating is an estimated date (posterior density estimate) for the final ring of the dated timber to which, if it lacks the waney edge, a sapwood allowance has to be made to obtain the estimated felling date. The original reports or publications should be consulted for details of sapwood estimates used. The results are generally presented as cal (calibrated) AD years with 95.4% probability limits (unless otherwise stated) and the use of italics indicates that the result is a posterior density estimate which describes the distribution derived from mathematical modelling from the original dating information; it should be noted that more than one felling date range may be indicated with a non-negligible statistical likelihood. Some samples can be securely dated using a combination of dendrochronology and radiocarbon analysis, where the radiocarbon wiggle-match allows a tentative tree-ring date for the site master to be accepted; the subscript DR is used to denote these dates. Unless otherwise stated, the results have been calibrated using IntCal20 (Reimer et al., 2020). The LEN numbers refer to the List Entry Number in the National Heritage List for England (www.historicengland.org.uk/listing/the-list/).