LEON ——Three years of digging at a prehistoric Indian site in Anne Arundel County has unearthed the oldest structures and human habitations in Maryland and is making this bluff above the Patuxent River one of the most important archaeological sites in the Mid-Atlantic.
Last week, archaeologists learned from carbon-14 dating that a stone hearth they uncovered this summer was last used 9,290 years ago. That makes the site, called Pig Point, twice as old as the earliest carbon-dated human habitation found previously in Maryland.
Beginning in 2009, the team led by Anne Arundel County archaeologist Al Luckenbach has found oval patterns of wigwam post holes dating from 800 to 3,000 years ago, the oldest human structures ever found in Maryland.
They have found highly decorated pottery, tools of stone and bone, personal ornaments, copper beads from the Great Lakes, exotic tools and ceramics from the Ohio and Delaware valleys, fossil shark teeth from Southern Maryland and shells from the ocean beaches.
"If you go to [archaeology] meetings like the Mid-Atlantic Conference, folks are just drooling over this stuff," said Dennis Curry, an archaeologist with the Maryland Historical Trust.
And it could get even better.
Luckenbach's team is still finding evidence of human occupations from the Early Archaic period, 10,000 to 8,000 years ago.
As they dig even deeper into the bluff, and back in time, the next period they would reach is the "Paleo Indian" or "Clovis" time, roughly 10,000 to 20,000 years ago. Those people were the earliest whose arrival in North America, via the Bering "land bridge" from Siberia to Alaska, is universally accepted.
Last year, neighbors showed Luckenbach several fluted Clovis spear points they picked up in a field at the foot of the bluff. So his team is now on the lookout for more Paleo-Indian artifacts in their excavations, finds they could document and date.
And as they dig, they have begun to consider the chances of finding even earlier artifacts, below the Paleo level.
Claims of "pre-Paleo" discoveries elsewhere in the United States and South America have been enormously controversial among scientists. But at Pig Point, where deep, "layer cake" deposits with solid C-14 dating make chronologies quite clear, such a find would be difficult to dispute.
That would be "the absolute jackpot," said Joe Dent, an associate professor and expert in Mid-Atlantic prehistory at American University in Washington. "If they encountered pre-Paleo, this would be an international site. Archaeologists worldwide would beat a path to it."
Luckenbach has said he believes Pig Point is already "the most important prehistoric archaeological site in Maryland."
Setting aside the extraordinary artifacts, archaeologists say Pig Point is most unique and valuable because of its nearly 10,000-year record of continuous human habitation.
"Most [Native American] sites in Maryland are 10 inches deep," Luckenbach said. The shallow deposits hold a mix of artifacts from successive Native American groups who lived there over hundreds or thousands of years, with little if any chronological separation. Often the shallow deposits have been churned for centuries by plows.
That makes it impossible to separate and study the material cultures and chronology of the people who left them behind.
There are a few deeply stratified archaeological sites. Curry cited one called the Monocacy Site, excavated in the late 1960s and early 1970s at the confluence of the Potomac and Monocacy rivers, near Dickerson.
"It's got probably 10 feet of stratified stuff," thanks to periodic river flooding, he said. "But most of that 10 feet is sterile soil [without artifacts], and covers maybe a thousand years."