For a limited time only, Metro Rail is offering scholars an opportunity for some time travel.
Archeologists are watching to see what buried artifacts subway builders may uncover as they dig holes for stations and access shafts for tunnels.
Already, some bottles and ceramic pieces from the turn of the century have turned up in shallow trenches.
Paleontologists have been assigned to watch for fossils. Deep pilot holes have already produced seashells, fish bones, and even a shark's tooth, from a time a million or 2 million years ago when the Los Angeles Basin was the ocean floor.
Archeologists say Metro Rail's most exciting cultural find would be remains of the original Indian settlement of Los Angeles; more likely would be relics from the city's first Chinatown.
Paleontologists say they are looking forward to the possibility of finding a whale.
Roberta S. Greenwood, whose urban archeological firm won the $160,000 contract to monitor Metro Rail digs for the Southern California Rapid Transit District, said she figures there is about a 40% chance of encountering remains of the long-lost prehistoric Gabrielino Indian village when workers dig up an area behind the Union Station passenger terminal next spring.
"There's been a lot of speculation about where the Indian settlement might have been," she said in a recent interview. "The Union Station area is the general area that many people have proposed."
Greenwood said there is only a slim chance, however, of finding significant artifacts from the Mexican settlement at the nearby pueblo of Los Angeles, founded in 1781.
Foundations from some of the original adobe houses are likely to be still in the ground, she said, because many of the replacement buildings did not have deep basements. "They did not necessarily disturb what was below. They simply built on it, paved over it," she said.
Metro Rail's first leg will run from Union Station through the Civic Center and Financial District to MacArthur Park, but will pass just to the north of the pueblo in a tunnel that will probably be too deep to intersect the foundations.
Some isolated artifacts from the Spanish era could be found, however. Old maps indicate that the Union Station subway digging sites were used by early settlers as orchards and farmland. "Things could have been dropped and lost or broken," Greenwood said.
But it is doubtful that archeologists will gain significant insight into pueblo culture from isolated finds.
Archeologists intent on unearthing information on earlier cultures are likely to concentrate their efforts at the Union Station digs.
Their study of early historical records has convinced them that they will not find much elsewhere, except perhaps an underground channel, part of the city's first water-distribution system, at the site of Metro Rail's 5th and Hill Street station.
Paleontologists, however, say all of the dig sites appear promising.
Bruce Lander, paleontological consultant to Greenwood, said Metro Rail digs will pass through rock composed of sand, silt and clay washed into the ocean by rivers between 5 and 10 million years ago. The particles settled on the ocean floor, where they were gradually compressed--perhaps along with fossils, Lander said.
Holes near 5th and Hill and 1st and Hill have already produced seashells, fish bones and sea urchin spines embedded in rock.
"Not too much yet," Lander said. But so far the excavations have been small.
"I think when the station (excavation) opens up and we have a chance to look at a lot of the rock, we'll probably find quite a bit," he said. "We expect . . . we'll be able to get hundreds or thousands of pounds of rock, haul them out of the station excavation and process them at another place so we don't hold up the (subway).
"There's always the possibility of getting a whale," he added, noting that he found part of one ancient skull himself while prospecting for fossils in the Santa Monica Mountains.
Excavations in urban areas produce all kinds of surprises. In San Francisco in 1981, for instance, workers installing a waste-water treatment line downtown found Gold Rush-era ships at anchor under what was solid ground. Part of the San Francisco Bay had been filled in, Greenwood said.
Subway workers in Mexico City encountered a well-preserved Aztec temple. In New York, they ran into a Dutch ship that had burned and sunk before New Amsterdam had been named, other archeologists said. In Vienna, they unearthed ancient Roman columns.
But in Rome, where "pretty much every time you dig a hole you find something . . . I don't think they found anything startling in connection with the subway," said Susan Downey, a professor of art history at UCLA. "They found a sarcophagus of a young woman and bits and pieces of buildings all over the place."