Bronze age Sardinia shows its metal

Science News, Oct 2, 1993

More than 7,000 skillfully engineered stone towers and numerous surrounding villages dot the Mediterranean island of Sardinia. These sites, built between about 1800 B.C. and 800 B.C. by members of the Nuragic culture, have yielded a variety of copper, bronze, lead, and iron artifacts. Archaeologists have now uncovered the first extensive evidence for a sophisticated metalworking facility at a Nuragic settlement.

"The existence of a true metal workshop provides convincing proof that the Nuragic people employed advanced metallurgical technologies in Late Bronze Age Sardinia;' the researchers assert. Lenore J. Gallin of the University of California, Los Angeles, and Robert H. Tykot of Harvard University describe their find in the fail JOURNAL OF FIELD ARCHAEOLOGY.

From 1986 to 1989, Gallin directed excavations at a Nuragic site that consists of a central tower, at least three associated towers, and a large surrounding village enclosed by a stone wall. She and her co-workers uncovered metal slag (waste produced during metal smelting), terra-cotta crucibles containing residues of molten metal, a lead ingot, lead scrap, and more than 200 copper-based artifacts. They also found hundreds of fragments of fire-blackened clay molds and cores; metalworkers apparently made bronze objects by pouring molten material into a mold, allowing it to harden, and then breaking the mold.

Some mold fragments contain incised designs and may have been used to make ornate sword handles and other decorative items, Gallin and Tykot contend. Investigators have also found molds for practical implements, such as hammers and picks.

The molds contain layers of two different clays, a polished form on the inner surface and a porous strip that allowed gases to escape during solidification of molten metal, the researchers say. Chemical analyses suggest that metalworkers sometimes added lead to bronze to improve its casting properties.

Nuragic metalworkers at the site probably manufactured bronze objects from the 12th to the 8th centuries B.C., according to Gallin and Tykot.