July 29, 2002
Scientists Determine Age of New World Map
“Vinland Map” parchment predates Columbus’s arrival in North America
Scientists from the University of Arizona, the U.S. Department of Energy’s Brookhaven National Laboratory, and the Smithsonian Institution have used carbon-dating technology to determine the age of a controversial parchment that might be the first-ever map of North America. In a paper to be published in the August 2002 issue of the journal Radiocarbon , the scientists conclude that the so-called “Vinland Map” parchment dates to approximately 1434 A.D., or nearly 60 years before Christopher Columbus set foot in the West Indies.
“Many scholars have agreed that if the Vinland Map is authentic, it is
the first known 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 chemist Garman Harbottle,
the lead Brookhaven researcher on the project. “If it is, in fact, a
forgery, then the forger was surely one of the most skillful criminals
ever to pursue that line of work.”
The map, drawn in ink and measuring 27.8 x 41.0 centimeters, surfaced in Europe in the mid-1950s, but had no distinct record of prior ownership or provenance in any famous library. The map and the accompanying “Tartar Relation,” a manuscript of undoubted authenticity that was at some point bound with the Vinland Map in book form, were purchased in 1958 for $1 million by Paul A. Mellon, known for his many important gifts to Yale, and, at Mellon's request, subjected to an exhaustive six-year investigation.
In 1965 the Yale University Press published “The Vinland Map and the Tartar Relation,” a detailed study by R.A. Skelton, T. E. Marston and G. D. Painter that firmly argued for the map’s authenticity, connecting it with the Catholic Church’s Council of Basel (A.D. 1431-1449), which was convened a half-century before Columbus’s voyage. Two scientific conferences, in 1966 and 1996, featured strong debates over the map’s authenticity, but no final determination could be made based on the available facts.
Beginning in 1995, Harbottle, along with Douglas J. Donahue, University of Arizona, and Jacqueline S. Olin, Smithsonian Center for Materials Research and Education, undertook a detailed scientific study of the parchment. The scientists traveled to Yale, where they were allowed to trim a 3-inch-long sliver off the bottom edge of the parchment for analysis. Using the National Science Foundation-University of Arizona’s Accelerator Mass Spectrometer, the scientists determined a precision date of 1434 A.D. plus or minus 11 years. The unusually high precision of the date was possible because the parchment’s date fell in a very favorable region of the carbon-14 dating calibration curve. This new analysis of the map parchment reaffirms the association with the Council of Basel since it dates exactly to that time period, and makes a strong case for the map’s authenticity.
Several previous studies challenging the map’s authenticity have focused on the chemical composition of the ink used to draw it. Some initial work found anatase, a particular form of titanium dioxide, in the ink. Since anatase only went into commercial production in the 20th century, some concluded that the ink was also a 20th-century product, making the map a forgery. Recent testing, however, only revealed trace quantities of titanium, whose presence may be a result of contamination, the chemical deterioration of the ink over the centuries, or may even have been present naturally in the ink used in medieval times. Another recent study detected carbon, which has also been presented as evidence of a forgery. However, carbon can also be found in medieval ink. Current carbon-dating technology does not permit the dating 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,” said Harbottle.