The discovery of thousands of artifacts dating to the Gold Rush represents the "birthplace of Chinatown," said an archaeologist.

The find is the "most significant" discovery of Chinese material in California since the wreck of a 16th century Spanish galleon carrying Ming Dynasty-era pottery was found at Point Reyes north of San Francisco a few years ago, Clarence Shangraw, the chief currator of the city's Asian Art Museum, said Tuesday.The artifacts were found during the past two weeks during excavations of a site for a 20-story bank and will be displayed at the Asian Art Museum. City law requires all construction sites to be evaluated for their archaeological value.

"I am hoping that these things will really be able to add a tangible dimension to early Chinese history in California," said urban archaeologist Allen Pastron. "They will help tell us how they lived, what they did and their relationship to other parts of the community."

Pastron said the discovery of bottles, pottery, coins and even an opium pipe bowl, indicate the site was a store operated by Chinese merchants in 1850 and 1851.

The building is assumed to have burned or exploded in one of a half-dozen fires that devastated San Francisco between 1849 and 1851, collapsing onto itself.

"What we have down here is a moment in time," Pastron said. The store represents "literally the birthplace of Chinatown," he said.

After the discovery of gold in California, Chinese came to San Francisco, then a tent city they called Gum San or "Big City of the Golden Hill."