Archaeologists who unearthed a prehistoric campsite west of San Jacinto say carbon dating has confirmed their belief that it may represent the earliest known site in the Western Hemisphere where humans fired ceramics.

Archaeologist Melinda Horne said two samples dated at about 9,000 years old by a Florida laboratory were associated with the use of ceramics. One artifact was a fire hearth, and the other was a grinding stone, or metate.

"They were directly associated with ceramics," Horne said. "They were fired and molded by hand. . . . This is a very, very significant find."

The campsite, west of San Jacinto near the Ramona Expressway, was discovered in April about 11 ½ feet below ground in a trench dug for the Metropolitan Water District's Inland Feeder pipeline project.

Horne and archaeologist Susan Goldberg, who assisted in the discovery, work for Applied EarthWorks, a firm hired by Metropolitan to monitor and to curate archaeological materials discovered along the 44-mile route of the Inland Feeder, which winds through portions of Riverside and San Bernardino counties.

The firm this month received carbon-dating results on four artifacts submitted to Beta Analytic Laboratories in Miami. Three of the four artifacts were dated at 9,000 years old or older, Horne said.

That would put the site within the Holocene epoch of geologic time, a period immediately following the Pleistocene epoch, or Ice Age. Within Southern California only an archaeological site in Irvine that was discovered in the early 1970s is of comparable age in terms of human use of ceramics.

Hundreds of what are believed to be tools were found at the site. The campsite's hearth contained numerous bones of small mammals, which apparently were a staple of the camp inhabitants' diet. Many of the artifacts indicated a common use of pigments and decorative objects, the archaeologists said.

No evidence of human remains was found.

Horne said she has contacted scientists at the Smithsonian Institution, who have expressed interest in analyzing the campsite artifacts.

She and Goldberg plan to publish a series of articles on their discovery in scientific journals, Horne said.

Published 9/18/1998