Sticky tape: A key ingredient for mapping artifact origins

Graphic: Artifacts from Kyoden that were being sampled for vermilion applying sulfur-absolutely free adhesive tape. (major and bottom remaining) Earthenware fragments. (major appropriate) Stone tool. (bottom appropriate) Potsherd. Arrows point to the sampled…
view more 

Credit: RIKEN

Scientists at the RIKEN Nishina Heart for Accelerator-Dependent Science in Japan have shown that combining a remarkably delicate sulfur examination technique with basic sulfur-absolutely free tape is an helpful and harmless way to take a look at extremely modest samples of vermilion from artifacts that are hundreds of several years previous. Posted in the Journal of Archaeological Science: Studies, the review used this technique to validate that trade probably existed between Japan’s northern island of Hokkaido and the western section of Japan’s mainland–a length of around 1000 miles–extra than 3000 several years in the past.

Vermilion, in some cases named cinnabar, is a bright pink mineral that was used in paintings, figurines, statues, ceramics, and ritual ceremonies dating again practically 9000 several years throughout Europe, Asia, and the Americas. The chemical name for vermilion is mercuric sulfide, and modest variants in sulfur can distinguish a person batch of vermilion from a further. In every single vermilion sample, some of the sulfur atoms are normal, though some are isotopes with two more neutrons. Because the ratio of these atoms does not alter around time, it can be used as a fingerprint to detect the place the sample arrived from.

Not long ago, Kazuya Takahashi and his colleagues in the Astro-Glaciology Investigation Group designed a remarkably delicate system for analyzing sulfur isotope ratios that only needs 1 microgram of vermilion–a person millionth of a gram–which is about five hundred moments smaller than what other approaches need to have. This is essential for the reason that the smaller the sample, the less damage to the artifacts remaining analyzed.

Following acquiring this new technique, Takahashi recognized that they desired a way to gather the little samples, retaining in head that the samples need to have to be burned up to create sulfur oxide fuel throughout the examination. The easiest way was to use a little 3 mm × 3 mm square of adhesive tape to pick up the vermilion from an artifact. Then, the vermillion and tape could be areas into the equipment and analyzed. Even so, most tape has sulfur, and presented the minuscule measurement of the sample, even the tiniest amount of money would throw off the results. Following trying quite a few unique industrial tapes, he got lucky. “By probability, I satisfied an previous close friend who operates in a business that sells unique types of tape. She realized of a person tape that could be sulfur absolutely free, which was a excellent recommendation for me!”

The team analyzed this polyester adhesive tape as very well as two other tapes from nearby outlets. They located that the shop-acquired tapes contained about .five% sulfur, though the particular tape did not comprise any sulfur. Now they were being ready to take a look at the program on actual artifacts.

An region in western Japan named Izumo has an archaeological site with artifacts from a settlement about 3500 several years in the past. Men and women have speculated that the men and women of that period traded thoroughly inside Japan. With cooperation from the nearby authorities in Izumo, the scientists gathered vermilion samples from artifacts excavated from the site and used their remarkably delicate examination technique to establish their sulfur isotope ratios. Then, they when compared the sample ratios to the ratios located at eight cinnabar ore mines throughout Japan. They located that most of the artifacts contained vermilion that was probably mined in the Northern island of Hokkaido, extra than 1000 miles absent, alternatively than in nearer mines positioned in western Japan.

Archaeologists often wish to assess the origins of pigments on wall paintings or pottery, but in quite a few conditions, the artifacts are also essential to damage even a modest amount of money for sample assortment. “Our system might open the doors for new research into historic trade routes and the history of person operates of historic art,” notes Takahashi.

The precision of the program can however be enhanced. “Analyzing sample origins applying sulfur isotopic ratios is not ample at the current time,” suggests Takahashi. “Applying ratios from multiple factors can enable us to estimate the origins extra exactly than regular approaches can.” The team has by now commenced analyzing guide (Pb) and sulfur isotopic ratios of pigment samples from historic Roman wall paintings located in Spain.

As is often the scenario, the success of this challenge relied on technological innovation that was in fact created for a totally unique objective. “This is an intriguing application of our isotope examination technique,” notes Yuko Motizuki, director of the Astro-Glaciology Investigation Group. “But it was at first designed for getting measurements in Antarctic ice cores, which is the major focus of our laboratory.

“We hope archaeologists and research facilities all over the environment can use Takahashi’s technique to acquire their very own measurement programs and keep on researching how historic peoples interacted and traded throughout continents.”

###

Disclaimer: AAAS and EurekAlert! are not accountable for the precision of information releases posted to EurekAlert! by contributing institutions or for the use of any facts as a result of the EurekAlert program.