Ancient tin mine found in Turkey

USA Today (Society for the Advancement of Education), June, 1995

Researchers have found a local Bronze Age source of tin in the Middle East. a discovery proving the metal that made the alloy possible was not imported entirely from regions outside the area as had been thought, Aslihan Yener, a University of Chicago archaeologist, indicates. She believes a mine and an ancient mining village she discovered in the Central Taurus Mountains in Turkey demonstrate that tin mining was a well-developed industry in the area as long ago as 2870 B.C., at the dawn of the Bronze Age.

Bronze is an alloy made by combining copper with as much as five-10% tin. Because it more easily is cast in molds and is harder than copper, bronze replaced copper in the production of tools, weapons, and ornamental objects. The Bronze Age lasted until 1100 B.C., when iron became the most important metal in manufacturing.

The site of the mine, Kestel, is about 60 miles north of Tarsus. Yener's work at the mine and at nearby Goltepe, an ancient miners' village, provides new insights into the development of the tin industry. Perhaps most important is her discovery that it can be smelted at relatively low temperatures in crucibles.

"The underground mining system at Kestel measures more than two miles." The shafts are about two feet wide, which made them difficult to enter by adults. "The mining was done with stone tools and fire." Miners would light fires by the ore veins, thus making it easier to batter away the ore. The mine probably produced about 5,000 tons of ore during its 1,000 years of operation.

The narrow measurements of the shaft suggest that children would be the right size to be workers there. Yener and her colleagues also recovered a burial site inside the mine with the skeletons of a number of 12- to 15-year-old miners, a finding she says supports the view that children were the miners at the site.

The tin ore first was washed. much the way panners in the 19th-century American West recovered gold, then was ground and smelted in covered crucibles, into which workers blew air through reeds. Droplets of tin were encased in molten slag. which was ground out, rewashed, and resmelted in a labor-intensive, repetitive process. This use of stone tools to crush not only ore, but also slag to release tin globules, makes more than 50,000 stone tools found at the site more easily understandable.

Radio-carbon dating showed that Goltepe was occupied from 3290 B.C. to 1840 B.C. it developed over several phases and began as a community of pithouses built into the soft sedimentary bedrock. Later, a walled community developed. Several hundred people probably lived on the site. "It is unclear whether the food used by the community came in as trade or if some form of agriculture did take place," Yener points out. Terraces on mountain slopes suggest that some crops may have been raised there.