Archeology

							     Peggy joins with 
							     archeologists to 
							     excavate a Hohokam 
							     village near Tucson

Contents

Insights & Connections
Vocabulary
Resources
Main Activity
Try This

INSIGHTS

Being an archeologist is a lot like being a detective. You spend most of your time trying to find clues, collecting information, and putting pieces together to solve a mystery. Both professions require a variety of tools and draw information from many different scientific disciplines. In fact, the only major difference is that detectives usually can question a witness while archeologists are lucky to find the witness's home! In the hands of a skilled archeologist, however, even a pile of trash can speak volumes.

Archeologists must first know where to look for a site. The passage of time and the forces of nature often erase even the sturdiest buildings. Walking an area, archeologists look for special clues that tip them off to human occupation. Some broken pieces of pottery, an old arrowhead, or even a pile of stones can lead them to a site. Before digging, however, they map the surface in detail and sometimes attempt to "see" below the ground with the help of remote sensing techniques like radar.

Once digging begins, workers scrape off each level in neat horizontal layers, a painstakingly slow process. Archeologists carefully observe rules of three important concepts: stratigraphy, superposition, and context. Stratigraphy means that the material covering the site was placed there in layers-or strata. Superposition means that the deeper you dig, the older the material gets. While these rules don't give exact ages, they allow scientists to calculate relative time, which is almost as important. Context is also a critical concept, since artifacts only tell a story through the context in which they're found-where they are found and with what they are found.

After uncovering artifacts, an archeologist relies on techniques like X rays and chemical and microscopic analysis to determine what materials were used to make the artifacts, how they were made, their age, and their purpose. If enough artifacts are found, the archeologist puts them together into common groups called assemblages. By studying assemblages, the archeologist can then determine what people did in different parts of the site at different times.

CONNECTIONS

1. Contrary to popular belief, archeologists do very little digging at a site, preferring to leave most of the artifacts buried. Why don't they dig up the whole area? What advantages could that have in protecting the site? How do they know what is buried at the site without digging it up?
2. How do the techniques used by archeologists compare to those used by geologists? State similarities and differences.
3. In forests, people often encounter lines of large rocks, long rows of old trees, and several ponds clustered in a small area. While all these features appear natural, could they be a result of human activity? Explain.

• archeologist a scientist who studies past cultures or people by analyzing the things they left behind (sites and artifacts)
• artifact any object made or used by people
• radar a device that images an object from a distance by reflecting radio waves off of it and analyzing the signals
• remote sensing a mapping technique that scientists use to analyze materials and landscapes from a distance, without making direct physical contact
• site a geographic area once occupied by people
• strata horizontal layers of soil or rock
• survey examination of Earth's surface to discover archeological sites

RESOURCES

• Brain, J. (Ed.) (1976) Clues to America's past. Washington, DC: The National Geographic Society.
• Corbishley, M. (1990) Detecting the past. New York: Glouster Press.
• Coville, B. (1990) Prehistoric people. New York: Doubleday.
• Fagan, B. M. (1992) People of the Earth: An introduction to world prehistory. New York: Harper Collins.
• Freeman, M. (1967) Finding out about the past. New York: Random House.
• Scott, A. (1993, Summer) Ancient tech. Invention and technology, pp. 34-44.
• Willey, G., & Sabloff, J. (1974) A history of American archaeology. San Francisco: W.H. Freeman.

• Local historical society
• College anthropology department
• State historic preservation office

RECORDING A SITE

Main Activity

Even before digging a single hole, archeologists develop a working model of what took place in an area. To do this, they conduct a survey to discover all the sites on the surface of the land and to describe what they can see at each site. Pieces of broken pottery, rocks arranged in patterns, and even trees growing in straight rows suggest that people once occupied an area. Using a local park or vacant lot, test your own ability to unravel past events.

Materials

• notebook and pencil
• ruler
• magnetic compass
• protractor
• large sheet of drawing paper

1. Select a site for your survey. A wooded park, a campground, or even a vacant lot will do fine. Before starting, ask for permission to enter the property if it is privately owned!

2. Using your compass to establish north, measure the site boundaries by pacing off the distance in feet in each direction. Log the direction and distance of your site boundaries in your notebook. To calculate your pace size, do the following:

   With a long tape measure, mark off two points exactly 100 feet (30m) apart. Starting at one point, walk in a direct line toward the other point, counting the number of steps you take to get there. Your steps should be your normal pace. Divide 100 feet (30m) by the number of steps you took. This number is your normal pace size. For example, if you took 25 steps, your pace would be 100 feet divided by 25 = 4 feet/step (30 ¸ 25 = 1.2 meters/ step). For more accuracy, you should repeat the measurement four times and average your results.

3. Starting at one corner of the site, walk slowly across the site in a systematic pattern. The best way is to cross back and forth at a regular interval of spacing. Look for anything that appears out of the ordinary-a broken bottle, an old can, a ring of rocks with some burnt material on the inside. Each time you encounter an artifact, describe it fully in the notebook and measure its distance and direction from one of the site corners.

4. Once you have completed your survey, plot your data on a scale map of the site. With your protractor, measure the compass direction from north and, with your ruler, measure off a scale distance. When all the data is plotted, see if you can find any patterns suggesting how people used the site.

Questions

1. When conducting site surveys, why walk back and forth in a regular pattern across the site rather than randomly?

2. What artifacts suggest that your site might be old? Which artifacts suggest your site has been recently used?

Artifacts don't have to be thousands of years old to be interesting. Your family may have some tools, games, or toys at home that no one knows how to use. Check out your grandparents' home to find some really old stuff and invite your friends to collect some of their own "blasts from the past." Hold a "What is it?" day to see how many different uses you can come up with for each artifact. Have your grandparents show you the correct use.

Visit a local historical society or museum to learn about people who lived in your area before the turn of the century. Find out who settled the area and identify the oldest known structure. Are there any archeological excavations nearby? If so, check them out!

Set up an excavation in a box. Get a 50-pound (22.5 kg) bag of topsoil. Starting at the bottom of the box and moving upward layer by layer, bury a number of different items associated with different tasks, such as cooking, cleaning, sewing, etc. Each group of associated items is called an assemblage, and they must be buried together on the same level. Invite some friends to help excavate and see if they can work out the context of events. (Example of a cooking assemblage: spoon, egg shells, milk carton, can opener.)

Newton's Apple is a production of KTCA Twin Cities Public Television.
Made possible by a grant from 3M.
Educational materials developed with the National Science Teachers Association.