Groundbreaking study: Ancient tin ingots found in Israel were mined in England


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Groundbreaking study: Ancient tin ingots found in Israel were mined in England
Enigma of origins of Bronze Age Levant’s tin supply solved through isotope and chemical composition analysis that shows 13th–12th century BCE tin bars likely came from Cornwall
By Amanda Borschel-Dan
Today, 7:48 pm

When the Bronze Age hit ancient Israel, the copper-rich region was able to quickly source seven of the eight ingredients needed to produce the alloy at Timna and other mines. But where tin — another one-eighth of the metal’s recipe — came from has been a lingering mystery for scholars. A new paper from an international team of researchers proposes a surprisingly faraway source — Cornwall.

In a paper published in June on the open-access, peer-reviewed scientific journal PLOS One, the authors analyze 27 tin ingots, or blocks, from five sites bordering the eastern Mediterranean Sea. For decades, researchers have debated the origin of tin used in ubiquitous precious bronze throughout the Levant during the eponymous era, from the late fourth and third millennia BCE. Hypotheses have swung from close-by Turkey, central Asia, or far-flung France and Britain.

In their paper, “Isotope systematics and chemical composition of tin ingots from Mochlos (Crete) and other Late Bronze Age sites in the eastern Mediterranean Sea: An ultimate key to tin provenance?” a team of interdisciplinary scientists from Mannheim, Germany; Greensboro, North Carolina; Merano, Italy; and Haifa have what they call solid proof of where — and where not — the precious tin was likely mined.

“Bronze was used to make weapons, jewelry, and all types of daily objects, justifiably bequeathing its name to an entire epoch. The origin of tin has long been an enigma in archaeological research,” said Prof. Dr. Ernst Pernicka in a press release this week. Study co-author Pernicka, now retired, worked at both the Institute for Earth Sciences of Heidelberg University and the Curt Engelhorn Centre for Archaeometry.

The scholars used an earth-shattering approach to figure out the mine’s locus. “By using a combined approach of tin and lead isotopes together with trace elements it is possible to narrow down the potential sources of tin for the first time,” they write. The most logical source? According to the authors, the most likely suppliers of the 13th–12th century BCE tin ingots from Israel are tin mines from Cornwall and Devon.

“These results specifically identify the origin of tin metal for the first time and therefore give rise to new insights and questions for archaeological research,” said lead author Dr. Daniel Berger, a researcher at the Curt Engelhorn Centre for Archaeometry in Mannheim.

All in the timing

The scientists studied samples that were discovered in dives off the coasts of Mochlos, Crete, and Uluburun, Turkey, and in three locations off Haifa, Israel. The ingots discovered in the three sites off the coast of Israel set the “geological model age of the parental tin ores” at circa 291 million years ago (with an error margin of 17 million years). The “age” of the tin is important for excluding other previous leading mine contenders — tin deposits in Anatolia, central Asia and Egypt — “since they formed either much earlier or later,” write the authors.

Tin is moderately rare essential metal that is found sporadically in sites spread out around the globe. Having excluding the close-by sites through the tin’s age, with the new study of the tin isotope composition, the authors state that they were also able to exclude several of the European sources as the origin mine for the Israeli ingots. Interestingly, the tin ingots from coastal Crete and Turkey appear to have a different source.

Archaeologists have found evidence of tin mining in Cornwall and Devon as early as 2000 BCE and the last tin mine in Cornwall, South Crofty, was only closed in 1998. Other ancient methods of mining the metal, such as sifting river water, leave few or no artifacts, meaning the metal may have been harvested from these areas even earlier.
Dr. Ehud Galili of University of Haifa taking core samples from the newly excavated Neolithic well in Kfar Samir (Dr Jonathan Benjamin courtesy of Dr Ehud Galili, University of Haifa and Israel Antiquities Authority)

The story behind each of the Israeli ingot samples is as astounding as the new study’s results.

In 2014, a team of archaeologists including the study co-author, Haifa University’s Ehud Galili, discovered what media sensationally called a Neolithic “Atlantis” off the coast of Haifa in Kfar Samir. There, they found the remains of a 7,700-year-old sunken village. The village, located about 200 meters (218 yards) offshore under some 5 meters (16 feet) of seawater, yielded ancient evidence of olive oil production, some of the oldest wooden artifacts in the world, according to a 2014 Times of Israel article, and ancient tin.

An earlier find of a 13th‐century BCE shipwreck at Hishuley Carmel in 2012 also was a source of the study’s tin ingots. That shipwreck, wrote Galili in a 2012 article in the International Journal of Nautical Archaeology, “provides direct evidence for marine transport of copper and tin along the Israeli coast and may indicate inland and maritime trade‐routes of metals in the Mediterranean.” At that point, however, author Galili had not yet determined the source of the discovered tin.

The precious

Knowing the origin of the Israeli tin ingots points to a complicated and far-reaching ancient trade route.

“Tin objects and deposits are rare in Europe and Asia,” said Pernicka. “The Eastern Mediterranean region, where some of the objects we studied originated, had practically none of its own deposits. So the raw material in this region must have been imported.” According to a press release from Heidelberg University and the Curt Engelhorn Centre for Archaeometry in Mannheim about the study, other “highly appreciated raw materials” that would have passed along the trade route include amber, glass, and copper.

Originally, bronze was created by mixing copper with arsenic. The poisonous element, however, created toxic fumes that led to metallurgists’ early deaths. Tin was found to be more stable — and less lethal — but somewhat elusive. Tin once held a value and strategic importance similar to that of oil, according to the research paper “Tin Deposits and the Early History of Bronze” by geologist R.J. Cathro. “Judging by how much effort went into finding it, the price of tin must have been extremely high,” writes Cathro.

“It became an indispensable commodity, worth scouring the world for and going to war over, and it occupies a special place in the history of mining, economic geology, agriculture, warfare, art, and human development,” writes Cathro. “Gold and silver could finance a war, but bronze could win it.”