Determination of the radiocarbon age of parchment of the Vinland Map

The Vinland Map, drawn on a 27.8 x 41.0 cm parchment bifolium, is housed in the Beinecke Rare Book and Manuscript Library at Yale University. In the northwest Atlantic Ocean, it shows "the Island of Vinland, discovered by Bjarni and Leif in company." Skelton, Marston, and Painter (Skelton et al. 1965, 1995) firmly argued the map's authenticity, associating it with the Council of Baste (AD 1431-1449), that is, half a century before Columbus's voyage. Nevertheless, vigorous scholarly questioning of the map's authenticity has persisted (Washburn 1966; McCrone 1974; Olin and Towe 1976; Cahill et al. 1987; McCrone 1988; Towe 1990). We have determined the precise radiocarbon age of the map's parchment by accelerator mass spectrometry (A-MS). The one-sigma calibrated calendrical date range is AD 1434 +/- 11 years: the 95% confidence level age range is AD 1411-1468.