Statistical Reanalysis and IntCal20 Calibration of the Published 1988 AMS Determinations (Nature Column)

A reanalysis of the published 1988 AMS radiocarbon determinations for the Shroud of Turin sample material. Using the 12 “Nature” measurements (Arizona, Oxford, Zürich) as reproduced by Casabianca et al., the paper tests inter-laboratory heterogeneity with Ward and Wilson diagnostics, reports both fixed-effect and heterogeneity-robust random-effects pooled estimates, and calibrates results with the IntCal20 curve. Calendar-year inferences are presented in two forms: an unconstrained, data-only calibration (reported transparently in the appendix, including multimodality from the calibration curve) and a primary, clearly labeled historical terminus ante quem constrained calibration using TAQ = AD 1354 based on Encyclopaedia Britannica’s first-attestation date. Conclusions are restricted to the dated material tested in 1988, with full methodological details and sensitivity checks for alternative TAQ values.