by David Kluth
Earlier this year, I traveled to the rolling hills of southern Wisconsin with Rocky
Mountain Archaeologist Ree Rodgers to participate in a workshop that taught the use of remote-sensing technologies to identify and evaluate archaeological resources. The workshop was sponsored by the National Park Service’s Midwest Archaeological Center.
The workshop, titled “Archaeological Prospection: Advances for Non-Destructive Investigations in the 21st Century,” took place May 19-23, and was dedicated to the use of geophysical; aerial photography; light detection and ranging, or LIDAR, which is similar to radar; and other methods as they apply to the conservation and protection of archaeological resources. With the increase of environmental and political pressures mandating archeological and other cultural resource assessments, the application of geophysical and other types of remote-sensing techniques to cultural resource management is increasing. The devices we learned about and used allow archaeologists to identify archaeological sites and pinpoint possible cultural features without having to use destructive and costly excavation techniques.
Rodgers and I attended lectures on the theory of operation, methodology, processing and interpretation during the morning sessions with hands-on use and operation of the equipment at the site during the afternoon sessions. Forty-six students participated in the workshop, which was taught by 17 instructors, many of whom have worked on archaeological sites around the world. Some of the remote-sensing techniques used were ground-penetrating radar, magnetometers, large- and small-scale resistivity, electromagnetic conductivity and metal detecting.
Upper Great Plains Archaeologist David Kluth operates a four-sensor magnetometer at Aztalan State Park in Wisconsin, May 22, to learn more about the land and people who inhabited it from 900-1200 A.D. (Photo by Ree Rodgers)
Anomalies may lead to new investigations
The course was held in Lake Mills, Wisconsin, at Aztalan State Park, the location of one of the state’s most important archaeological sites. Aztalan is a village that thrived from 900-1200 A.D. The people who settled Aztalan built large, flat-topped pyramid-shaped mounds and a stockade around their village. Although the site has been scientifically studied since 1836, it has never been surveyed using such a wide variety of geophysical techniques. The intention of the workshop was to shed new light on the ancient village by identifying previously unknown features and, therefore, new areas for investigation.
Results of the students’ survey work were presented to the group following the week-long training. Resistivity studies conducted on different soils within the complex archaeological site identified those soils that were modified by humans and those that were naturally occurring. Initial data obtained from the magnetometer and ground-penetrating radar equipment identified new anomalies that could be hearth features, storage pits, house basins or possibly even a new line of palisade walls. Low-level aerial photographs taken from an ultralight plane identified site features and how they relate to the surrounding environment while LIDAR data displayed new internal site structure that may help interpret the site more fully. When data from all these different applications is compared, the resulting information will likely identify new areas for the archaeologists to investigate that may not have been considered before the workshop.
Devices save time, reduce project costs
Western operates more than 17,000 miles of transmission lines and hundreds of substations and communication sites. There are 14 interconnection projects in Upper Great Plain’s queue alone. The workload is growing every year, and archaeological contractors are beginning to use new techniques to identify and evaluate historic sites to save time and reduce project costs.
This workshop helped us understand how remote-sensing devices and techniques are used, what types of data can be obtained by each device and how they can be best applied in the field to provide the data necessary to identify and preserve our cultural heritage. The training will also help us interpret information presented by archaeological contractors. As the use of these geophysical techniques becomes more prevalent within the archaeological community, we will have the skill and knowledge to conduct surveys, identify cultural sites, review client information and make informed decisions to interpret and protect cultural resources that may be affected by Western projects.
Rocky Mountain Archaeologist Ree Rodgers (center with sunglasses) watches a demonstration about how to program a ground-penetrating radar machine, May 20, in Lake Mills, Wisconsin. (Photo by David Kluth)