SUITLAND, Md. – For the first time, scientists have ascribed a date – A.D. 1434, plus or minus 11 years – to the parchment of the controversial Vinland Map, possibly the first map of the North American continent.
Collaborators from the Smithsonian Center for Materials Research and Education, the University of Arizona, Tucson and the U.S. Department of Energy’ s Brookhaven National Laboratory used carbon-dating techniques to analyze the parchment on which the map is drawn.
Authenticity. Their findings place the parchment of the map 60 years ahead of Christopher Columbus’ arrival in the West Indies, and provide compelling evidence that the map is authentic.
“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, researcher.
Favorable period. Researchers sampled the bottom right edge of the parchment for analysis. The unusually high precision of the date was possible because the Vinland Map’s date fell in a 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, convening between 1431 and 1449.
Paul A. Mellon had purchased the map and manuscript for $1 million in 1958, and requested the study after donating them to Yale.
Background. 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 comes 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 today’s 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. Nevertheless, carbon can be present in a medieval ink.
Explanation. “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.
“The elemental composition of the ink is consistent with a medieval iron gall ink, based on historical evidence regarding ink production,” she said.
Present carbon-dating technology does not permit the analysis of samples as small as the actual ink lines on the map.
“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,” she said.
