James F. Deetz, 70, a University of Virginia historical archaeology professor since 1994 who was a past director of the Museum of Anthropology at the University of California at Berkeley, died of pneumonia Nov. 25 in Charlottesville.

Dr. Deetz, who lived in Charlottesville, was a leading authority on North American colonists and a developer of historical archaeology.

Although he established his reputation in digs in New England, he had taught anthropology at Berkeley from 1978 to 1994 and also was a museum official from 1979 to 1988.

Dr. Deetz, who had been a visiting professor at the College of William & Mary in the 1970s, was the author of several texts, including "Invitation to Archaeology," which was published in 1967, and "In Small Things Forgotten: The Archaeology of Early American Life," which was published in 1977. Both are still in use.

He published his final book, "The Times of Their Lives: Life, Love and Death in Plymouth Colony," co-written by his wife, cultural historian Patricia Scott Deetz, a month before his death.

The Los Angeles Times was among many news organizations that sought his counsel about the historic roots of Thanksgiving. He spent two decades excavating and reconstructing Plimoth Plantation in Massachusetts, becoming an authority on the roots of the first Massachusetts Thanksgiving feast in 1621.

"Thanksgiving is better understood if we think of the Pilgrims as bawdy Elizabethans, which they were," he once told the Los Angeles Times. "They were hearty drinkers, they liked to dance, and they swore. Court records from Plymouth Colony show drunken behavior in public, fighting, swearing."

Among the details he determined from his work and shared annually were: The menu probably included pumpkin soup but no pie, ducks and geese and eel and venison but no turkey, corn and beer and maybe wine; Indians outnumbered Pilgrims 90 to 50; they danced, showed off their skills at musketry (colonists) and shooting bows and arrows (Indians), and played games but probably didn't pray; the Pilgrims wore bright-colored clothing, jackboots and plumed hats, not black and white garments with buckled shoes and hats.

And "none of the settlers called themselves Pilgrims," Dr. Deetz said. "One-third of the settlers were of the separatist religious group, and called themselves Saints. They referred to the other two-thirds, who were Anglicans, as Strangers."

When Dr. Deetz took over the museum at Berkeley, it had about 4 million items--the largest of its kind in the western United States--and the number of items grew under his scrutiny. It was the minutiae collected in archaeologists' digs, he said, that helped define history.

Dr. Deetz was born in Cumberland, Md., and studied anthropology at Harvard University. He became attracted to the study of colonists during his doctoral research on their interaction with American Indians of the Plains, and during his excavations at Plimoth Plantation.

He taught simultaneously at the University of California at Santa Barbara and Brown University from 1961 to 1967, when he became assistant director of the Plimoth Plantation, the outdoor-history-museum reconstruction of the early colonists' village near Plymouth, Mass. He remained there until moving to Berkeley.