"Many scholars have agreed that if the Vinland Map is authentic, it is the first cartographic representation of North America, and its date would be key in establishing the history of European knowledge of the lands bordering the western Atlantic Ocean," said Jacqueline S. Olin, assistant director for archaeometric research at SCMRE when the study began in 1995. Olin and co-authors Douglas Donahue, a physicist at the University of Arizona and Garman Harbottle, a chemist at Brookhaven National Laboratory, along with SCMRE paper conservator Dianne Van Der Reyden, sampled the bottom right edge of the parchment for analysis. The dating was carried out at the National Science Foundation-University of Arizona Accelerator Mass Spectrometer in Tucson. The unusually high precision of the date was possible because the Vinland Map's date fell in a very favorable region of the carbon-14 dating calibration curve.
The parchment analysis again indicates the map's connection with the Catholic Church's Council of Basel, convened between 1431 and 1449, first posited by R.A. Skelton, T.E. Marston and G.D. Painter, the scholars who undertook a six-year investigation of the Vinland Map and accompanying "Tartar Relation," and made their argument for the map's authenticity in the book, The Vinland Map and the Tartar Relation, published in 1965 by Yale University Press. Paul A. Mellon had purchased the map and manuscript for $1 million in 1958, and requested the study after donating them to Yale.
The map came to light in Europe in the mid-1950s without any record of previous ownership or provenance in any library or collection. It is now in the collection of Yale's Beinecke Rare Book and Manuscript Library in New Haven, Conn. The name "Vinland" derives from text on the map that recounts Bjarni and Leif Eriksson discovering "a new land, extremely fertile and even having vines, … which island they named Vinland." The "Island of Vinland" appears on the map in the northwest Atlantic Ocean. Scholars postulate it may represent present-day Labrador, Newfoundland or Baffin Island. The map also shows Europe, Africa and Asia.
Several previous studies challenging the map's authenticity focused on the chemical composition of the ink used to draw it, and pointed to the presence of anatase, which was not produced commercially until the 20th century. But there are questions about how an ink containing anatase could have been formulated and used by a forger. More recently, the ink has been shown to contain carbon, which also has been presented as evidence of a forgery. However, carbon can be present in a medieval ink.
"Anatase may be a result of the chemical deterioration of the ink over the centuries, or may even have been present naturally in the ink used in medieval times," Olin said, adding, "The elemental composition of the ink is consistent with a medieval iron gall ink, based on historical evidence regarding ink production."
Present carbon-dating technology does not permit the analysis of samples as small as the actual ink lines on the map.
Concluded Olin, "While the date result itself cannot prove that the map is authentic, it is an important piece of new evidence that must be considered by those who argue that the map is a forgery and without cartographic merit."
The article is available online at www.radiocarbon.org.
The Smithsonian Center for Materials Research and Education advises and assists the Smithsonian and other museums in the study, preservation and conservation of artistic and historic objects. Its staff conducts research in the areas of material technology, chemistry, art and cultural history, as well as in the development of treatment procedures. The Center also offers educational programs about the properties and preservation of collections to museums and associated professionals around the world.
Note to editors: Brookhaven National Laboratory and the University of Arizona are issuing concurrent releases.