Radiocarbon Dating of the Shroud of Turin by P. Tite6 Reprinted from Nature, Vol. As Controls, three samples whose ages had been determined independently were also dated. The results provide conclusive evidence that the linen of the Shroud of Turin is mediaeval. The Shroud of Turin , which many people believe was used to wrap Christ's body, bears detailed front and back images of a man who appears to have suffered whipping and crucifixion. It was first displayed at Lirey in France in the s and subsequently passed into the hands of the Dukes of Savoy.
After many journeys the shroud was finally brought to Turin in where, in , it was placed in the royal chapel of Turin Cathedral in a specially designed shrine. Photography of the shroud by Secondo Pia in indicated that the image resembled a photographic 'negative' and represents the first modern study. Subsequently the shroud was made available for scientific examination, first in and by a committee appointed by Cardinal Michele Pellegrino 1 and then again in by the Shroud of Turin Research Project STURP 2.
Even for the first investigation, there was a possibility of using radiocarbon dating to determine the age of the linen from which the shroud was woven. To confirm the feasibility of dating the shroud by these methods an intercomparison, involving four AMS and two small gas-counter radiocarbon laboratories and the dating of three known-age textile samples, was coordinated by the British Museum in The results of this intercomparison are reported and discussed by Burleigh et al.
Following this intercomparison, a meeting was held in Turin in September-October at which seven radiocarbon laboratories five AMS and two small gas-counter recommended a protocol for dating the shroud. At the same time, the British Museum was invited to help in the certification of the samples provided and in the statistical analysis of the results. The shroud is sample 1, and the three controls are samples Note the break in age scale.
Ages are given in yr BP years before Removal of samples from the shroud The sampling of the shroud took place in the Sacristy at Turin Cathedral on the morning of 21 April Tite of the British Museum, representatives of the three radiocarbon-dating laboratories Professor P. Hedges and Professor W. Riggi, who removed the sample from the shroud. The strip came from a single site on the main body of the shroud away from any patches or charred areas.
The samples were then taken to the adjacent Sala Capitolare where they were wrapped in aluminium foil and subsequently sealed inside numbered stainless-steel containers by the Archbishop of Turin and Dr Tite.
Samples weighing 50 mg from two of the three controls were similarly packaged. The three containers containing the shroud to be referred to as sample 1 and two control samples samples 2 and 3 were then handed to representatives of each of the three laboratories together with a sample of the third control sample 4 , which was in the form of threads.
All these operations, except for the wrapping of the samples in foil and their placing in containers, were fully documented by video film and photography.
The laboratories were not told which container held the shroud sample. Because the distinctive three-to-one herringbone twill weave of the shroud could not be matched in the controls, however, it was possible for a laboratory to identify the shroud sample. If the samples had been unravelled or shredded rather than being given to the laboratories as whole pieces of cloth, then it would have been much more difficult, but not impossible, to distinguish the shroud sample from the controls.
With unravelled or shredded samples, pretreatment cleaning would have been more difficult and wasteful. Because the shroud had been exposed to a wide range of potential sources of contamination and because of the uniqueness of the samples available, it was decided to abandon blind-test procedures in the interests of effective sample pretreatment.
But the three laboratories undertook not to compare results until after they had been transmitted to the British Museum. Also, at two laboratories Oxford and Zurich , after combustion to gas, the samples were recoded so that the staff making the measurements did not know the identity of the samples. Controls The three control samples, the approximate ages of which were made known to the laboratories, are listed below.
Two were in the form of whole pieces of cloth samples 2 and 3 and one was in the form of threads sample 4. Plumley for the Egypt Exploration Society in On the basis of the Islamic embroidered pattern and Christian ink inscription, this linen could be dated to the eleventh to twelfth centuries AD. This corresponds to a calendar age, rounded to the nearest 5 years, of cal BC - AD 75 cal at the 68 per cent confidence level 5 where cal denotes calibrated radiocarbon dates.
Measurement procedures Because it was not known to what degree dirt, smoke or other contaminants might affect the linen samples, all three laboratories subdivided the samples, and subjected the pieces to several different mechanical and chemical cleaning procedures. All laboratories examined the textile samples microscopically to identify and remove any foreign material. Zurich precleaned the sample in an ultrasonic bath. After these initial cleaning procedures, each laboratory split the samples for further treatment.
The Arizona group split each sample into four subsamples. One pair of subsamples from each textile was treated with dilute HCL, dilute NaOH and again in acid, with rinsing in between method a. The second pair of subsamples was treated with a commercial detergent 1. The Oxford group divided the precleaned sample into three. Two of the three samples were then bleached in NaOCL 2. The Zurich group first split each ultrasonically cleaned sample in half, with the treatment of the second set of samples being deferred until the radiocarbon measurements on the first set had been completed.
The first set of samples was further subdivided into three portions. One-third received no further treatment, one-third was submitted to a weak treatment with 0. After the first set of measurements revealed no evidence of contamination, the second set was split into two portions, to which the weak and strong chemical treatments were applied.
All of the groups combusted the cleaned textile subsample with copper oxide in sealed tubes, then converted the resulting CO2 to graphite targets.
Arizona and Oxford converted CO2 to CO in the presence of zinc, followed by iron-catalysed reduction to graphite, as described in Slota et al. Zurich used cobalt-catalysed reduction in the presence hydrogen, as described by Vogel et al.
Each laboratory measured the graphite targets made from the textile samples, together with appropriate standards and blanks, as a group a run. Each laboratory performed between three and five independent measurements for each textile sample which were carried out over a time period of about one month.
The results of these independent measurements Table 1 in each case represent the average of several replicate measurements made during each run samples are measured sequentially, the sequence being repeated several times. The specific measurement procedures for each laboratory are given by Linick et al. Table 1 Basic Data individual measurements.