WASHINGTON (November 5, 1998) -- Ancient residents of the Andes Mountains produced delicate gold and copper foils, 1,000 years earlier than archaeologists had previously thought they learned to work metal.

"This was astonishing," anthropologist Richard L. Burger of Yale University said of the find.

Burger and Yale geologist Robert B. Gordon report their discovery, made in the Lurin Valley south of Lima, Peru, in Friday's
edition of the journal Science.

The foils were produced between 1410 and 1090 B.C., roughly the period when Moses led the Jews from Egypt and the era
of such pharaohs as Amenhotep III, Tutankhamen and Ramses.

The earliest previous evidence of metalworking in the Andes was by the Chavin and Cupisnique cultures between 600 and 200
B.C.

"These artifacts reveal a previously unknown stage of Andean metalworking," Burger wrote.

The area is known as Mina Perdida, meaning lost mine, he said in a telephone interview.

Local residents had asked the researchers if they were looking for the area's legendary hidden treasures of gold, Burger said,
but he told them no, confident that the ancient people of the area had done no metalworking. The researchers were simply
studying the ancient cultures of the area.

"I was shocked," he said of finding several examples of copper and gold foils. "These early examples of Andean metalworking
... show three patterns that were to characterize the Central Andean metalworking tradition for the next three millennia." They
include "an unusual concern with the production of thin metal foils, the gilding of copper, and the close association of
metalworking with religious ritual and the supernatural realm."

Burger said he isn't sure how the foils were used, but noted that later people had a tradition of beating metal into thin foils and
attaching it to cloth.

The bits of foil, none in a recognizable shape, were found in one of six ceremonial centers in the valley. That particular
ceremonial center is on a natural terrace above a flood plain and is topped by a flat-topped pyramid 71-feet high.

Elaborate carvings of supernatural beings on the walls of buildings at the six centers, as well as the presence of ceremonial
paraphernalia, indicate the centers were used for religious rituals as well as other civic purposes, the researchers said.

A nearby site contains unbaked clay relief sculptures painted red and cream color which form a gigantic mouth with interlocking
teeth and giant fangs, Burger said. "You walk into the mouth when go into the sacred precinct."

The foils were dated with tests on carbon atoms connected to them. Similar dates were found in tests on fiber bags containing
fill found on top of the metal.

There were two lower mounds in the area with the remains of dwellings and household refuse but no metals were found there.

The gold was worked cold, pounded with stone hammers into foils between 0.1 and 0.05 millimeters thick (0.004 to 0.002
inch). In some cases there was evidence of gold foil glued to copper.

The metal was not smelted, but some of the copper had evidence of heating when it was worked, Burger said.

By RANDOLPH E. SCHMID, Associated Press Writer