Vindication for Vinland map: New study supports authenticity

November 24, 2003

Recent conclusions that the storied Vinland Map is merely a clever forgery are based on a flawed understanding of the evidence, according to a scientist at the Smithsonian Institution. Results from last year's study debunking the map's authenticity can also be construed to boost the validity of its medieval origins, the scientist claims. The report will appear in the Dec. 1 edition of Analytical Chemistry, a peer-reviewed journal of the American Chemical Society, the world's largest scientific society.

The Vinland Map is a drawing of Iceland, Greenland and the northeastern seaboard of North America that has been dated to the mid-15th century, suggesting that Norse explorers charted North America long before Columbus. The map, which has had a contentious history since its discovery in the 1950s, resides at the Beinecke Rare Book and Manuscript Library of Yale University. It has been valued at more than $20 million.

"Many scholars have agreed that if the Vinland Map is authentic, it is the only existing cartographic representation of North America prior to Columbus," says Jacqueline Olin, a member of the advisory committee of the Smithsonian Center for Materials Research and Education in Washington, D.C. "Its date is important in establishing the history of European knowledge of the lands bordering the western North Atlantic, and the deeper question of Columbus's own possible awareness."

In July 2002, two papers about the Vinland Map were published simultaneously in separate scientific journals -- one in Radiocarbon, which set a date for the map's parchment at about 1434 using carbon dating; and another in Analytical Chemistry, claiming that the map is really just a clever 20th-century forgery on medieval parchment.

Olin, who was involved in the Radiocarbon research, wrote the new Analytical Chemistry paper in response to the controversy sparked by last year's dueling papers.

Since the age of the parchment is not in dispute, Olin says, "The information needed to prove that the Vinland Map is medieval rests with the ink used to draw it."

Before the development of the printing press, manuscripts were written in either carbon-based inks or iron gallotannate inks. Erosion of the latter often leads to yellow staining - a feature exhibited by the Vinland Map.

In last year's Analytical Chemistry paper, British researchers analyzed the ink with Raman microprobe spectroscopy and claimed that it is made up of two parts: a yellowish line that adheres strongly to the parchment overlaid with a black line that appears to have flaked off.

Because they found the black line contained carbon, the researchers assumed the ink was not iron gallotannate, meaning there should be no yellow staining. They proposed that the yellow line was put there by a clever forger who knew it was a common feature of medieval manuscripts. This line contained anatase, a precipitated form of titanium dioxide. Since anatase was not synthesized until 1917, they considered this as evidence that the Vinland Map is a forgery.

To the contrary, the ink may help prove the map's authenticity, says Olin. "The presence of carbon in an ink is not evidence that the ink is a carbon ink," she says. "It could just as well have been iron gall ink to which carbon has been added as a colorant." Carbon was added to medieval iron gall inks to enable scribes to view their writing while the transparent ink mixture was reacting to form its black color.

"The source of the iron in medieval inks is green vitriol, an iron sulfate," Olin continues. "Green vitriol would include anatase if the iron source from which it was made included the iron-titanium mineral ilmenite."

Researchers have reported the absence of ilmenite in the ink of the Vinland Map, but that would only mean it was not present in the sulfate used to make the ink, Olin says. In earlier work, she made a simulated 15th century ink using ilmenite for the preparation of green vitriol. The resulting ink contained anatase, and no ilmenite.

There has also been no discussion about the significance of the other elements found in the ink, Olin says. She used archaeological reports to show that the presence of copper, aluminum and zinc -- all found in the Vinland Map's ink -- would be consistent with medieval production methods from green vitriol. Additionally, these elements raise serious doubts about the possibility of forgery, because 20th century iron gall inks would not be produced using medieval hydrometallurgy, which is responsible for the presence of these elements. No forger in the first half of the 20th century could be expected to know about these extra components, according to Olin.
-end-

-- Jason GorssThe online version of the research paper cited above was initially published Oct. 24 on the journal's Web site. Journalists can arrange access to this site by sending an e-mail tonewsroom@acs.orgor calling the contact person for this release.

American Chemical Society

Related Carbon Articles from Brightsurf:

The biggest trees capture the most carbon: Large trees dominate carbon storage in forests
A recent study examining carbon storage in Pacific Northwest forests demonstrated that although large-diameter trees (21 inches) only comprised 3% of total stems, they accounted for 42% of the total aboveground carbon storage.

Carbon storage from the lab
Researchers at the University of Freiburg established the world's largest collection of moss species for the peat industry and science

Carbon-carbon covalent bonds far more flexible than presumed
A Hokkaido University research group has successfully demonstrated that carbon-carbon (C-C) covalent bonds expand and contract flexibly in response to light and heat.

Metal wires of carbon complete toolbox for carbon-based computers
Carbon-based computers have the potential to be a lot faster and much more energy efficient than silicon-based computers, but 2D graphene and carbon nanotubes have proved challenging to turn into the elements needed to construct transistor circuits.

Cascades with carbon dioxide
Carbon dioxide (CO(2)) is not just an undesirable greenhouse gas, it is also an interesting source of raw materials that are valuable and can be recycled sustainably.

Two-dimensional carbon networks
Lithium-ion batteries usually contain graphitic carbons as anode materials. Scientists have investigated the carbonic nanoweb graphdiyne as a novel two-dimensional carbon network for its suitability in battery applications.

Can wood construction transform cities from carbon source to carbon vault?
A new study by researchers and architects at Yale and the Potsdam Institute for Climate Impact Research predicts that a transition to timber-based wood products in the construction of new housing, buildings, and infrastructure would not only offset enormous amounts of carbon emissions related to concrete and steel production -- it could turn the world's cities into a vast carbon sink.

Investigation of oceanic 'black carbon' uncovers mystery in global carbon cycle
An unexpected finding published today in Nature Communications challenges a long-held assumption about the origin of oceanic black coal, and introduces a tantalizing new mystery: If oceanic black carbon is significantly different from the black carbon found in rivers, where did it come from?

First fully rechargeable carbon dioxide battery with carbon neutrality
Researchers at the University of Illinois at Chicago are the first to show that lithium-carbon dioxide batteries can be designed to operate in a fully rechargeable manner, and they have successfully tested a lithium-carbon dioxide battery prototype running up to 500 consecutive cycles of charge/recharge processes.

How and when was carbon distributed in the Earth?
A magma ocean existing during the core formation is thought to have been highly depleted in carbon due to its high-siderophile (iron loving) behavior.

Read More: Carbon News and Carbon Current Events
Brightsurf.com is a participant in the Amazon Services LLC Associates Program, an affiliate advertising program designed to provide a means for sites to earn advertising fees by advertising and linking to Amazon.com.