By Betsa Marsh, Denver Post
Beer
cans crumpled round a dead campfire, signs of late-night
partying scorched into the sandstone. In a cutaway 15 feet below
the modern fire circle, there's more charred stone, flecked with
the shells of Ohio River mussels and the bones of passenger
pigeons — both long extinct.
In
between the two fire rings? The oldest site of human habitation
in North America, at least 16,000 years old. That's the
surprise of Pennsylvania's Meadowcroft Rockshelter, an inviting
sandstone overhang in a tributary valley of the Ohio River
that's been welcoming fishers, hunters and travelers since the
Paleo-Indians. The site in Avella, 30 miles southwest of
Pittsburgh, is now a National Historic Landmark, set amid
towering sycamore and pawpaw trees. Its 52 carbon dates, in
almost perfect stratigraphic order, reflect a continuous human
record for 16,000-plus years.
"It was like a Paleo motel," guide Eleanor Crowe said. "People
would come along Cross Creek, 7 miles from the Ohio River, and
stay here, from the earliest Paleo-Indians to the time of
European settlement."
Closed in 2007, the landmark has reopened now,
with a new shelter of its own, a $2.3 million enclosure that's
bolted into the bedrock and raked at an improbable 17-degree
angle. A new roof protects the archaeological dig, and new
platforms allow more visitors to see the excavated levels and
start piecing the timeline together for themselves.
"Until we completed the new structure, there was just a
temporary wooden structure built by the archaeologists to
protect the site," said director David Scofield. "Ten people was
a crowd."
Archaeologists began digging and sifting in 1973, led by
University of Pittsburgh professor James M. Adovasio. He and his
students at Pitt held six consecutive field schools there.
Later, Adovasio founded the Mercyhurst Archaeological Institute
at his new school, Mercyhurst, in Erie, Pa., and he's brought
Mercyhurs t archaeology students to Meadowcroft into the new
millennium.
For now, the dig is quiet, but millions of bone fragments, plant
materials and cultural artifacts such as basketry fragments are
being studied at Mercyhurst.
Thirty-five years ago, however, Meadowcroft seemed like just a
good spot for field study, a "closed site" unexposed to the
elements. These "often served as veritable magnets for
prehistoric and historic populations," Adovasio, a Youngstown
native, wrote of the rock shelter.
Meadowcroft was south of the last Ice Age glaciers. When an ice
dam broke between 40,000 and 22,000 years ago, the racing water
scooped out the softer sandstone and left the overhang, its
ceiling about 43 feet above the modern surface of the shelter.
From about 21,000 years ago, when the water subsided — long
before the Egyptian pyramids and the Greek Parthenon were
glimmers in anyone's eyes — the rock shelter was ready for
visitors.
Facing south for warmth, with a good east-west breeze, this spot
50 feet above the north shore of Cross Creek would stay dry and
well ventilated. It remained more than 93 miles south of the ice
front. Permanent springs to the east and west made it ideal for
hunter-gatherers to stay for a few days or to set up a fall
hunting camp.
We can still see a deer rib bone sticking out of the rock, proof
that Indians butchered their kill here about 40,000 years ago.
But what of the first inhabitants?
As Adovasio and his students bore down into the layers of silt,
the cultural evidence kept getting older and older. By the time
they hit bedrock — about 15 feet down — Adovasio was sending
specimens for carbon dating and the word back was staggering: at
least 16,000 to 17,000 years old.
But perceived wisdom in archaeology said that people arrived in
the New World relatively late, about 11,500 years ago,
"signaled," as Adovasio wrote, "by the appearance of a genuine
North American invention: the Clovis projective point,"
a specific type of stone tool and spear point.
Could Meadowcroft really be 4,000 years older?
Skeptical scholars
Adovasio
and his work set off a firestorm that has raged for more than 30
years. Some archaeologists claim his samples were
contaminated, possibly by nearby coal fields. After Blacksmith
Jay Hoffman helps re-create a mid-1800s Pennsylvania settlement
just another point on the site's long timeline of human use.
(Betsa
Marsh, Travel Arts Syndicate )results came back from four labs
around the world with no signs of contamination — and
identical carbon dates — some scientists changed their minds.
With the discovery of several 0D sites as old as Meadowcroft,
more archaeologists have accepted the "breaking of the Clovis
barrier."
As one of the professors on the Landmarks Committee of the
National Park System Advisory Board wrote about Meadowcroft,
"First and foremost, the meticulous way in which the rock
shelter was excavated is a credit to the excavators. Moreover,
its thick deposits are rich in artifactual remains, with just
about every cultural period of Eastern Woodlands prehistory
represented."
Most of those critical artifacts are at Mercyhurst, but
travelers can see some projective points from 4,000 B.C. to
2,000 B.C. in the
Meadowcroft Museum. Many were gathered by landowner Albert
Miller, a naturalist and amateur archaeologist who was convinced
since boyhood that the rock shelter on his family farm must have
been used by prehistoric people.
Walking the area on Nov. 12, 1955, Miller noticed a groundhog
had dug a new burrow. "I went home for a screen and a
long-handled shovel," he later wrote. "About 12 inches
down I realized I was coming up with burnt bone and flint, which
I knew was Indian. At about 30 inches I found a complete
Indian-made flint knife."
He quickly re-covered the spot. "I never told another person,
knowing that if word got out, pick-and-shovel 'pot hunters'
would quickly destroy the archaeological value of this rock
shelter. An archaeological site is like reading a book written
long ago. Pot
hunters looking for something of monetary value would proceed to
destroy these unread pages."
Miller tried for years to interest professionals in the site.
Carnegie Museum of Natural History staff tried a test unit in
1967. Once
they hit rocks from a roof fall, they aborted the dig and no one
touched Meadowcroft until 1973, 18 years after Miller's
discovery.
Now, travelers come from around the world to see its strata tell
their tales back in time, and a sandstone wall with scorch marks
and charcoal from campfires over thousands of years.
About a third of the site remains untouched, preserved for
future archaeologists with as-yet-undreamed technologies.
Who knows, they may find even more interesting things around the
modern-to-prehistoric campfire than crumpled beer cans and
18th-century colonial gin bottles.
"People would have partied here for a lot of years," guide Crowe
said of the hospitable rock shelter, "and they'd probably still
be partying if it wasn't for the dig."
