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A lone diver set eyes on the ancient Kyrenia shipwreck off the northern coast of Cyprus almost 60 years ago. But when archaeologists tried to establish the exact timeline of the vessel resting on the ocean floor, they were left to speculate based on the ship’s cargo.
Now, a new study published Wednesday in the journal PLOS One may have a better time estimate for Kyrenia’s demise – and the revelation came thanks to freshly cleaned wood samples from the ship, as well as clues that supplied a twig, an animal bone. and a cache of ancient almonds.
The Kyrenia ship, one of the first large Greek ships of the Hellenistic period to be found largely intact, was first discovered by local diver Andreas Cariolou in 1965 and excavated by a team led by the late marine archaeologist Michael Katzev. on the shipwreck and its cargo in the late ’60s.
The researchers initially believed that the vessel sank around 300 BC. Text only, the first volume of the site’s final reports published in 2022, estimated to range between 294 BC and 290 BC, based on pottery and some coins found on board. But no scientific dating was available to back up the estimates, according to the latest study.
By using radiocarbon dating — a method used to determine the age of organic materials, such as wood from trees — and dendrochronology, the science of dating tree rings, the researchers of the new study determined that the sinking of the Kyrenia occurred between 296 B.C. and 271 BC. And they found a strong probability that it happened between 286 BC and 272 BC, the authors of the study wrote.
“We found dates that are very close to those suggested by recent archaeologists but slightly later than ever,” said lead author Sturt Manning, distinguished professor of arts and sciences in classical archeology at Cornell University in New York. .
While an updated timeline backed by scientific data is important for the famous ship, the revelation is key in new techniques and revised radiocarbon calibration that will help scientists more accurately date structures and shipwrecks from this period, Manning said.
Chatting with a ship from the Hellenistic era
Two main obstacles stood in the way of achieving a high-precision age estimate for the Kyrenia wreck, according to Manning. The first was that polyethylene glycol or PEG, a petroleum-derived compound used to preserve the ship’s wood, was interfering with radiocarbon dating.
Often, shipwrecks remain well preserved due to the lack of oxygen at the bottom of the ocean. But when the materials are brought up to the surface, they deteriorate quickly, Manning explained. By injecting polyethylene glycol into the wood, the wood is kept from crushing and turning to powder, but it is difficult to remove gradually.
“You only have a fraction of a percent of this stuff (polyethylene glycol) there, and the date will be wrong, often by hundreds, if not thousands of years,” said Manning, who tried the Kyrenia to this. ship 10 years ago but failed due to PEG.
However, an international team of researchers developed a cleaning protocol, described in an October 2021 study, that successfully removed the petroleum-based compound from relatively recently preserved wood, Manning said. . To confirm that the protocol would work with something as old as the Kyrenia shipwreck, Manning and his colleagues applied the technique to a piece of PEG-preserved wood that they knew was nearly 2,000 years old and obtained accurate radiocarbon ages .
Now that they had a solution to clean the wood, the researchers thought they would be able to date the ship’s wood. But they ran into another roadblock instead and kept getting ages that didn’t match “any archaeological solution that might be around,” Manning said.
After investigating, he and his team determined that the international Northern Hemisphere radiocarbon calibration curve, which converts measurements to dates based on known tree rings, was out of date for the period between about 400 B.C. and 250 BC.
The researchers were able to form their date estimate by recalibrating the curve using sequoia and oak samples of known age from this period. The revision curve was crucial in introducing an accurate time frame for the Kyrenia shipwreck and could further help researchers around the world who have similar problems when tackling ancient structures, Manning said.
A treasure of ancient almonds
The radiocarbon ages from the wood gave researchers an idea of when the ship was built, but it was the cargo of almonds that gave the study authors an estimate of the date of the wreck, Manning said. “If you have a material like almonds – or you can imagine olives or anything like this that was used as a food crop – and it was on the ship when it sank, it has to be there probably from about a year… or maybe two years older than when the ship went down.”
By using the organic materials from the cargo, such as the almonds, an unidentified twig of wood that was not part of the ship’s construction, and a livestock ankle bone, the researchers were able to narrow down the dates and estimate a range of years for the time . The last voyage of the Kyrenia ship took place.
“Part of the value of this story is process. … the dating (radiocarbon) fields and the dendrochronology fields have grown, developed, refined their results for many years,” said Mark Lawall, a professor in the Department of Classics at the University of Manitoba in Winnipeg, in an email. “Science — whether ‘hard’ or ‘soft’ — develops over time through a lot of work ‘in the trenches’. It takes time and it needs time.” He was not involved in the new study.
With the slight modification of the estimated extinction date, it is significant that the original dates based on archaeological evidence of ceramics and coins were only a few years off, said Lawall, who studied amphorae, ancient Greek containers used for wine. sent, olive oil. and other articles, from the Kyrenia shipwreck.
“The rest of the story of Kyrenia is their window into past lives that are difficult to ‘see’ through the known (or even lesser known) ancient writers,” said Lawall. “Perhaps the crew of Kyrenia were a band of marginal traders, taking what they could, where and when they could, and hoping for a small profit at the end of the day.”
He added, “They dealt across cultures and in doing so were part of an extremely complex network that linked all parts of the Mediterranean together. In this way we begin to understand the origins of the modern, multicultural, interconnected Mediterranean world.”
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