Relation between D/H ratios and 18O/‘6O ratios in cellulose from linen and maize- Implications for paleoclimatology and for sindonology

The ‘*O/r60 ratios of cellulose and the D/H ratios of cellulose nitrate were determined for linen, a textile produced from the fibers of the flax plant Linum usitatissimum, and for maize (Zea mays) from a variety of geographic locations in Europe, the Middle East, and North and South America. The regression lines of bD values on 6”O values had slopes of 5.4 and 5.8 for the two species. Statistical analysis of results reported in the only other study in which samples of a single species (the silver fir Abies pindrow) that grew under a variety of climatic conditions were analyzed yielded slopes of -6 when 6D values of cellulose nitrate were regressed on 6”O values of cellulose. The occurrence of this previously unrecognized relationship in three species suggests it may obtain in other plants as well. Determining the basis for this relationship, which is not possible given current understanding of fractionation of the isotopes of oxygen and hydrogen by plants, should lead to increased understanding of how D/H and ‘8O/‘6O ratios in cellulose isolated from fossil plants are related to paleoclimates. The separation of most linen samples from Europe from those originating in the Middle East when 6D values are plotted against 6”O values suggests it may be possible to use the isotope ratios of cellulose prepared from the Shroud of Turin to resolve the controversy concerning its geographic origin. INTRODUCTION ceum) fibers included in the linen threads. This observation suggested that the linen may have been spun with the same equipment used previously for cotton. The cotton inclusions support a Middle Eastern manufacture, but do not prove it. A second line of evidence supporting a Middle Eastern origin comes from the pollen studies of FREI (1979). This work is inconclusive, however, because of lack of control studies and detailed descriptions of experimental procedure. None of the observations made during the most recent scientific study of the Shroud in 1978 (SCHWALBE and ROGERS, 1982) bear directly on age or geographic origin. THE SHROUD OF TURIN has been the subject of continuing controversy since it surfaced in France over six hundred years ago. A major issue concerns its origin. No one knows how old the Shroud is or where it came from, but opinions differ sharply nonetheless. Some think the Shroud was the burial cloth of Jesus. Proponents of authenticity believe the linen cloth was manufactured in or near Palestine during the early first century A.D. Opponents of this position refer to a letter written in 1389 A.D. by Pierre d’Arcis, Bishop of Troyes (WILSON, 1978). In it the bishop states that his predecessor had conducted an investigation into the matter and had turned up an artist who confessed to the forgery. In the sceptics’ view, the Shroud is thus a product of European technology of the 14th century. While these opposing positions in no way exhaust all possibilities, they have nonetheless remained predominant. It therefore seems appropriate that some experiments be done to test one hypothesis against the other. The available scientific information regarding the origin of the Shroud is largely inconclusive. RAES (1976) observed that neither thread-twist nor weave type of the Shroud is sufficiently distinctive to identify the origin of the linen fabric. He did, however, find traces of cotton (Gossypium herba’ Also, Archaeology Program and Laboratory for Biomedical and Environmental Sciences, University of California, Los Angeles, CA 90024, U.S.A., and Division of Geological and Planetary Sciences, California Institute of Technology, Pasadena, CA 91125, U.S.A. 2 Current address: Department of Geological Sciences, University of California, Santa Barbara, CA 93 106, U.S.A. 3 Current address: Biology Department, University of Miami, Coral Gables, FL 33 124, U.S.A. 4 Also, Anthropology Department, Harvard University, Cambridge, MA 02 136, U.S.A. ’ Current address: Geny Conservation Institute, Marina Del Rey, CA 90292, U.S.A. In 1984 Larry Schwalbe from Los Alamos National Laboratories invited us to become associated with STURP, the Shroud of Turin Research Project, a consortium of researchers interested in investigating various aspects relating to the origin and subsequent history of the Shroud and in persuading the Roman Catholic Church authorities in charge of the Shroud to permit such investigations. Our contribution to the program was to involve stable isotopic analysis of cellulose purified from a piece of the Shroud in order to limit its possible geographic origin, thereby adding some evidence to the question of its authenticity. The rationale behind our approach is as follows. If the Shroud is the burial cloth of Jesus, the flax (Linum usitatissimum) plants that were processed to produce the linen probably were grown in the Middle East in the 1st century A.D. On the other hand, if it is not authentic, the plants probably were grown in Europe in the 14th century A.D. We expected that stable isotopic analysis of cellulose from the Shroud would allow us to decide between these two geographic possibilities because (1) 6D and 6r80 values of meteoric water are influenced by climatic factors, with temperature being the most important determinant (DANSGAARD, 1964; FRIEDMAN et al., 1964); (2) D/H and r80/i60 ratios of cellulose reflect the corresponding isotope ratios of the meteoric water a plant used and the humidity of the environment in which it grew (EPSTEIN et al., 1976, 1977); so that (3) cellulose