ST. MARY'S CITY, MD., DEC. 4 -- After weeks of speculation, only one thing was certain: There are three very old lead coffins in a grassy field here where the first capital of the Maryland colony used to be.

One of them may or may not contain the remains of Philip Calvert, a prominent colonial figure who could afford to be buried so extravagantly. For now, only their undertakers know for sure.

After a host of speeches and photo opportunities, state archaeologists uncovered the last of the coffins today but could find no identifying marks that would indicate the identity of the occupants. It will be months before the experts decide on another method to learn who's in there without actually opening the airtight coffins -- which could destroy the contents if done improperly.

"It's a Geraldo Rivera thing," said Joseph Anderson, deputy director of the St. Mary's City Commission, the state agency charged with excavating the abandoned 17th century colonial capital, 80 miles southeast of Washington. "It could be Joe Schlivitz in there or something."

It was not Al Capone's safe, which Rivera revealed to contain nothing of interest after a big media buildup. But with a busload of high-profile state officials on hand, excavators here were hoping for much more.

Henry Miller, the chief archaeologist, figured that the largest of three coffins unearthed here contains the remains of Calvert, a half-brother of colonial proprietor Lord Baltimore and himself a governor of the colony before his death in 1682. Miller guessed that the two smaller coffins contain Calvert's nephew, William, and great-nephew, Cecil Calvert.

Scraping the dirt from the gravesite had revealed an unexpected skull and human bone, but no revealing letters or plaques on the smaller coffins. Removing the last few inches of soil from the largest coffin was left until noon today to accommodate Gov. William Donald Schaefer's schedule.

"This may possibly be the greatest discovery we've made in our time," said Schaefer, addressing a crowd of 50 dignitaries gathered by a tent erected over the site for the occasion. Schaefer was then presented with a golden trowel, with red, yellow and black ribbons tied to it.

The governor then joined archaeologist Molly Quast at the gravesite and commenced to dig. He scraped and chipped at the dirt for five minutes of photo opportunities. He then got up, and Quast continued the work with a trowel and a dust pan.

The graves are within the excavated foundation of what is called the Great Brick Chapel, said to be the first Roman Catholic Church in America. It was closed and dismantled in 1704, after the Protestants won control of the colony, moved the capital to Annapolis and outlawed Catholic worship.

All that was put aside today as Schaefer helped Quast in the quest for an identifying inscription.

When more than half of the coffin's surface was revealed, there was none.

"It's the Calverts. That's our story and we're sticking to it," said archaeologist Stephanie Bandey.

"We were hoping, of course, that it would say 'Phil Calvert' all over the coffin," said Burton K. Kummerow, executive director of the St. Mary's City Commission. "But it's never that easy."

In fact, two other lead coffins, opened half a mile from here in 1799, contained identifying initials inside, suggesting that opening these coffins could solve the mystery.

But what to do next remains to be seen. Miller said a panel of experts will be assembled to study the matter. Because the coffins are lead, X-rays won't work. Someone suggested a sonogram. In any event, nothing will be done over the winter, when the graves will be covered to protect them against the elements. Despite the uncertainty over what they had uncovered, those who assembled here celebrated . There was chili under the tent, and oysters, crabs and ham in the St. Mary's City museum auditorium, where Miller declared, "Maryland has a history second to none in this nation. It's time to start telling the world."