Long after the discovery of Anglo-Saxon burial grounds at the Sutton Hoo site in East Anglia, England, scientists are still analyzing the treasures discovered there. Perhaps the most famous grave at the site was discovered in 1939 by Suffolk amateur archaeologist Basil Brown. In a mound, he and his colleagues discovered the remains of a 90-foot Anglo-Saxon ship filled with grave goods, including shields, cauldrons, jewelry and a now-iconic iron-and-bronze helmet.
Remains of the high-ranking person buried here were dissolved by the acidic soil, but much of his loot remained intact. Safely stored in the British Museum, many artifacts from the burial chamber in the ship have been cataloged and displayed. Still, a few mysteries remain. For decades, no one could identify a cache of hard, black nuggets. They were tentatively categorized as pine tar, which the Anglo-Saxons would have used for waterproofing ships. Now a team of scientists has figured it out. Register PLoS Onethey describe using techniques such as mass spectrometry and gas chromatography to analyze the chemical composition of the clumps.
What the team found could change the way we understand trade relationships in the Anglo-Saxon world. The chunks turn out to be bitumen, a solid form of oil. Like tar, bitumen can be used for waterproofing. In the ancient world it was also used in medicine and embalming. Bitumen would have been extremely rare at the time of the ship’s burial. There are a few bitumen deposits in the west of England, but East Anglia was not trading with people in the rest of Britain at the time. Further analysis showed that the bitumen actually came from Syria.
Geochemist Stephen Bowden of the University of Aberdeen, who helped analyze the bitumen, explains in The Conversation how he and his colleagues discovered this:
Middle Eastern bitumen was used for many things in the ancient world, including embalming, medicine and, of course, waterproofing. This use left an archaeological record of bitumen that we could examine to look for a match. Bitumen families are a bit different from oil families. They have additional chemical properties that are obtained when oil is converted to bitumen. The kind of bitumen used in ancient times was formed by microbes that consumed the liquid parts of oil, leaving mostly solid residues behind. The results of this microbial conversion vary depending on the location of the bitumen.
The researchers are certain that this bitumen was not used in boat repair, but they are not sure how the Anglo-Saxons would have used it. Register PLoS Onethey suggest it could have been used as glue in jewelry or even a set of game pieces:
Bitumen can, of course, also be formed to make ornamental objects such as beads, dice and game pieces and the Sutton Hoo chunks may be the fragmentary remains of such small bitumen objects. Their distribution at the head and foot ends of the coffin places them close to the areas where the ivory game pieces were discovered in the burial, but the locations don’t correlate well enough to infer a connection.
We may not yet know how the Anglo-Saxons used Syrian bitumen, but we now have a better idea of how far their trade networks extended into the early medieval world. Given the geopolitics in Britain at the time, it was easier for an East Anglian nobleman to get bitumen from Syria than from the west of England.
PLoS One, 2016. DOI: 10.1371/journal.pone.0166276
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