Portuguese Rock Art Raises Ruckus
Scientific and political controversy is raging around several clusters of engraved animal portrayals found in the Coa Valley of northeast Portugal. The fate of a major dam may hinge on the resolution of widely disparate estimates of the age of this rock art.
On the scientific front, two reports in the December 1995 Antiquity provide starkly contrasting estimates. One analysis suggests that the engravings date to no more than several thousand years ago; the other supports a much older, Late Stone Age origin for the figures.
An archaeologist hired by Portuguese authorities to conduct independent dating tests last spring contends that evidence gathered so far places most of the engravings at 3,000 years old or younger. Radiocarbon dates were obtained from thin mineral layers that formed on some of the engravings, says Robert G. Bednarik of the International Federation of Rock Art Organizations in Caulfield South, Australia.
In addition, a preliminary microscopic analysis of erosion on the engravings suggests that those classed initially as Late Stone Age works are, in fact, of quite recent vintage, Bednarik asserts. Finally, he adds, a number of engravings bear marks made by metal points. Farmers who inhabited the Coa Valley around 1,700 years ago may have carved some of these figures, he holds.
Stylistic comparison with other prehistoric art specimens in western Europe places the Portuguese finds squarely in the Late Stone Age, argues Joao Zilhao of the Institute of Archaeology in Lisbon, Portugal. …