It was once considered the oldest known map depicting North America. But the Vinland Map, credited to early Viking explorers, is not what it initially seemed, according to Yale University, which acquired it in the 1960s. For one thing, the calfskin parchment map of the North American coastline southwest of Greenland—thought to have originated in the early to mid-15th century—is drawn in 20th-century ink, per Smithsonian. "The Vinland Map is a fake," Raymond Clemens, a curator at Yale's Beinecke Rare Book & Manuscript Library, declares in a news release.
For the first time, Yale researchers were able to examine the map alongside two texts with which it was originally bound: a medieval encyclopedia and a 13th-century account of Polish clerics’ ventures into the Mongol empire. Lining up wormholes, they found the map parchment came from the front of the encyclopedia and was probably an end sheet. Additionally, an analysis using macro X-ray fluorescence spectroscopy uncovered high amounts of titanium and traces of barium—used in pigments produced in the 1920s—"throughout the map's lines and text," according to Yale's release. Further tests suggested the ink was commercially produced in Norway in 1923.
Medieval scribes typically used iron gall ink, which is found on the back of the parchment. There lies a Latin inscription that perhaps served as a bookbinder's note on how to assemble the massive encyclopedia. Researchers say it was overwritten in modern ink—which Clemens sees as "powerful evidence that this is a forgery, not an innocent creation by a third party that was co-opted by someone else." There have been doubts about its authenticity for some time as the map depicts Greenland as an island, rather than a peninsula, as it was long assumed to be, per the New York Times. Earlier studies of the map also found evidence of modern ink. This latest analysis leaves "no reasonable doubt," Clemens says. (Read more Yale University stories.)