How do archaeologists know that there are things in the ground just by bumps on the ground? Couldn't they be anything?

Dr. dig responds:
Archaeologists learn to "read" the contours of a landscape for indications of human settlement. But it is often difficult to tell whether the humps and bumps on the ground are something man-made or just natural hiccups on the earth's surface.

One clue that a bump on the ground might be man-made is that it has a regular shape. For instance, a burial mound might form a perfect circle or the ditch around a lost fort or castle might form a square. Natural formations are not usually so regular in shape. Another clue would be that you might spot finds around the bump that would tell you that there had been some human activity in the area. If the place had been occupied by people long ago you would expect to find some pottery and building stone, or perhaps tools made from flint.

Sometimes bumps on the ground are not recognized as anything much until they are seen from high up in an airplane. Archaeological features, such as the walls of ancient buildings which are buried beneath the soil, affect the growth of crops and grasses on the surface of the soil. Bumps on the ground or the differences in the height of growing plants can be seen more easily from above, especially in the early morning or late afternoon when they cast the longest shadows. Archaeologists call the marks they see on the ground, crop marks.

How exactly do archaeologists know where to start digging? Is it just a hunch?

Dr. dig responds:
Archaeologists do depend on hunches, but usually these hunches are based on a good deal of knowledge they have learned about the place. Let's imagine, for instance, that your father has forgotten where he put his favorite magazine. You will have a hunch, of course, where he might have left it because you know a little about his habits. You know that he likes to read in the kitchen or in the bath. You also know the layout of the house where he lives. He could have left it on the second floor landing outside the bathroom, or on the backporch before he entered the kitchen from the garage. You will start looking in the obvious places first. Just like you, an archaeologist doesn't just start digging anywhere. Archaeologists usually know where to dig because they have learned a bit about the local history of whatever place they want to excavate. Archaeologists spend lots of time in libraries and museums to find out about the local history of a place and what has been recorded by people before them. Archaeologists also look for clues about the past from old buildings, or parts of buildings that have been reused in newer buildings.

In places like farmland or wilderness, archaeologists look for unusual mounds or shapes in the land that might not have been created naturally. They look for pictures of the land taken from airplanes. They look at books and maps for clues to buried sites. Sometimes, an archaeologist does learn about a site by accident - a farmer has dug up some old stone fundations, a plumber has stumbled upon an old well, a roadworker has come across an old cemetery. There are lots of ways an archaeologist knows where to dig - perhaps you will come across an important find or site andtell your state archaeologist who will conduct an excavation! You never know.

How do archeologists know where to find ancient artifacts? How do you know what to look for in a dig site? Do you always know exactly what your looking for?

Dr. dig responds:
Archaeologists don't always know where to look for sites and artifacts. Many sites and important artifacts are discovered by accident. For example, a farmer plowing a field might turn over facts to the remains of an old building, or construction workers digging the foundations for a building might turn up a long forgotten graveyard, or a repairman fixing an underground water main, might find a hoard of ancient coins. When an accidental discovery is made, responsible people call their local archaeologist and report the find.

Often, archaeologists are hired by construction companies or by the state to oversee building construction in sensitive historic areas. But sometimes archaeologists do know where many sites are because there are historical records, like maps, letters, travel diaries, and ancient writings that provide clues to the whereabouts of sites and monuments that once existed long ago.

Artifacts are found wherever there has been human activity in the past. If an archaeologist knows that people have lived in a place long ago, then there are likely to be artifacts left behind by those people. People are not very tidy and are always leaving stuff behind!

Remember, if you find a site or an artifact that you think is important, do not disturb it, but report it to your local or state archaeologist. Remember this motto: Help preserve the past for the future!