- The Washington Times - Thursday, April 18, 2002

Washington and the region surrounding it has been a hub of power and politics for hundreds of years. Think George Washington, Thomas Jefferson and George Mason, to name a few but that's hardly going back far enough.

American Indian findings in and around the District indicate that the region was home to wealthy chiefs for thousands of years, archaeologists say. They have found evidence that humans have been in the area since at least 9000 B.C.

How do they know that the evidence, such as a projectile point, which looks like an arrowhead (a later invention), is 10,000 years old as opposed to, say, 5,000 years old?

Archaeologists use several methods to identify and date objects they find. With artifacts from the prehistoric period up to the 1500s, when Europeans came to this continent and started writing down their observations one of the methods they use is radiocarbon dating, which was developed during World War II.

In radiocarbon dating, the breakdown of carbon isotopes in organic matter is measured. All plants and animals ingest carbon dioxide throughout their lives. When the plants and animals die, the radioactive carbon isotopes start breaking down.

The half-life of Carbon 14, the isotope measured, is 5,730 years. That means if half of the isotope remains in the organic matter, the object studied is 5,730 years old.

Over the years, the method has been refined, and now just a milligram of organic material is needed to date an object. A couple of decades ago, archaeologists needed about 8 grams for the same analysis.


The District and surrounding areas are littered with prehistoric sites where radiocarbon dating has been used to identify and date artifacts.

Inside the District, Indian sites have been found just north of the Kennedy Center, in Rock Creek Park and on American University's campus, to name just a few places.

"We have found 6,000-year-old projectile points right here on campus. I think it was at the Mary Graydon Building," says Joe Dent, a professor of anthropology with a specialty in archaeology at American University.

Indians probably were attracted to the area because of the easy access to the Potomac River and to the Chesapeake Bay, which were important for both fishing and transportation.

"It's as real estate agents today would say, 'It's all about location, location, location, '" says Stephen Potter, regional archaeologist for the National Capital Region of the National Park Service. He has three archaeologists under his supervision.

Every year there are about 50 archaeological projects in the District and surrounding areas. The projects are led by schools, such as American University and Mr. Dent; the National Park Service, which oversees digs in national parks; and local governmental groups, such as Alexandria Archaeology and the District Office of Historic Preservation.

Every time someone wants to build on federal land or use federal money, an archaeological study is commissioned to see if anything historically significant may be on the property, Mr. Dent says.

The most significant findings during the Metrorail excavations were Indian artifacts that were between 2,000 and 10,000 years old at the site of what is now the Greenbelt storage facility, he says.

Mr. Potter says he has seen his share of projectile points and pottery in his more than two decades as the lead archaeologist for the National Park Service in the region, but he's still excited about each new dig because it might tell him something he doesn't know.

"It is only through archaeology that we will find out about life here in prehistoric times," he says. "There is no written documentation."

During what he calls one of his most exciting projects, just north of the Kennedy Center the Ramp 3 excavation archaeologists discovered a burial site that was determined through radiocarbon dating to be about 1,300 years old.

It was the first time archaeologists in this area found grave "treasures," such as an antler comb and sharks' teeth, objects more typical for burials in areas farther northeast, such as upstate New York.

This could mean that some prehistoric peoples migrated from the north into the Chesapeake Bay region around A.D. 700, something not previously known.

•••

Mr. Dent will be excavating an Indian site in Poolesville, along the Potomac and west of Gaithersburg, this summer.

Archaeologists there are trying to determine whether the Indians who used the site about 800 years ago were sedentary. If they were, they might have been the first group in the area to have traded nomadic life for settled farming of corn, beans and squash, Mr. Dent says.

"The big question is whether the circular villages of 100 to 150 people were fortified with stockades or palisades. If they were, it would be a good indication of a sedentary lifestyle," Mr. Dent says.

Aside from radiocarbon dating, archaeologists can learn about prehistoric life by looking at the lifestyles of recent traditional, or primitive, cultures.

By studying Indians on the Plains in the 1800s, and even more recently the Australian Aborigines, archaeologists have been able to re-create a tool- and weapon-making technique called flint knapping.

The technique is simple but time-consuming. It entails using one stone as a tool to flake off pieces of another stone, which is designated to become, for example, a projectile point.


The need for archaeology may seem less apparent at more modern sites, such as Gunston Hall in Mason Neck, George Mason's 1760s home in southeastern Fairfax County so much is written about the time.

However, there always are details that historians and others miss or simply don't find interesting.

Christine Jirikowic, archaeologist at Gunston Hall, is trying to find out how Mason's original gardens looked by digging several feet into the ground of the current gardens, which were planted in the 20th century.

She is looking at different layers of soil for evidence of stakes that would have marked the perimeter of the garden and for old pebbles that would have been original pathways.

When an archaeologist identifies and dates artifacts based on how deep in the soil they are found and what objects might be lying above them, it's called superpositioning, or relative dating.

The concept is simple: What is closest to the surface is newer than what is farther down.

"So far, we have found fence posts that are 10 feet apart and a 12-foot-wide path," Ms. Jirikowic says.

The reason she knows the posts and path are from Mason's era is that objects found in the soil layers above them such as white ware, a type of everyday houseware, and nails were manufactured in the early 1800s.

Also, the path was described by Mr. Mason's son, John Mason, in accounts from the early 1800s, and the boxwoods that have engulfed the path are at least 250 years old as measured by their trunk rings.

Gunston Hall is not the only historic house in the Middle Atlantic area that has an archaeologist on staff. At Poplar Forest, Thomas Jefferson's home near Lynchburg, Va., archaeologists are excavating in search of slave quarters and garden layout.

At Mount Vernon, archaeologists are excavating a distillery George Washington built in 1797. Their goal is to figure out how the distillery's intricate water-supply system was set up.

•••

Though the District is rich in history and historical artifacts from local archaeological digs, residents haven't had a good opportunity to see the artifacts yet.

That will change in the spring of 2003, when the D.C. City Museum at Mount Vernon Square in Northwest is expected to open its doors, says Nancy Kassner, staff archaeologist for the District Office of Historic Preservation.

"It's a very exciting opportunity," Ms. Kassner says. "[In the past] I have only been able to show a few artifacts temporarily at libraries."

Other archaeologists also are very excited about the new museum. What they find during excavations can sometimes seem insignificant a shard here, a projectile point there but in the right context, each bit of evidence helps give a full picture of what life was like hundreds, even thousands of years ago.

"Archaeology is like pieces of a jigsaw puzzle," Mr. Dent says. "It's exciting when we find the corner pieces and we can resurrect people who are no longer around."

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