What led to the bioplastic coating hypothesis?
Several years before the carbon dating of the Shroud of Turin, Leoncio Garza-Valdes, a medical doctor and an amateur archaeologist from San Antonio, Texas, was examining a Mayan jade artifact that was assumed to be modern forgery. He was curious about a lacquer-like coating on the objectand speculated might have been produced by bacteria.
Garza-Valdes took the artifact to the radiocarbon dating lab at the University of Arizona. Radiocarbon dating technicians at the lab were able to scrape off enough of the coating, as well as some bloodstains on the object, to do a carbon dating and determined that the object was from about A.D. 400. The carving style, however, suggested that the age should have been about 200 B.C. If a bioplastic-polymer, for that is what it seemed to be, had been forming over many centuries, it would result in a mixture of older and newer material. So perhaps, he reasoned, the object really was 600 years older.
Later, after the carbon dating of the shroud in 1988, it occurred to Garza-Valdes that perhaps the fibers of the shroud were also coated with a bioplastic coating. If that was so, perhaps this also affected the carbon dating of mummy 1770. If ancient linen was subject to such a coating, then all bets were off on the carbon dating of the shroud until the problem was examined.
- Did a biological polymer throw off the carbon dating?
- Wasn't there an anomalous carbon dating of an Egyptian mummy?
- Why did the bio plastic hypothesis ultimately fail to convince researchers?