Ohio Valley Archaeology, Inc. is the leading cultural resource management firm in Ohio for near-surface geophysical survey on archaeological sites. Dr. Jarrod Burks is the director of geophysical survey and interpretation at OVAI.
Kinds of Geophysical Survey We Perform
- Magnetic Gradient, Instruments: Geoscan Research FM 256 and Foerster Ferex-DLG 4.032 4-probe cart-based system
- Electrical Resistance/Resistivity, Instrument: Geoscan Research RM 15 (advanced) Electrical Resistance Meter
- Ground Penetrating Radar (GPR), Instrument: Sensors and Software Noggin Smartcart 500
- Metal Detector, Instrument: Minelab Quattro MP; Fischer 1225-X
- Magnetic Susceptibility, Instrument: Bartington MS2 System with MS2B lab sensor and MS2D field loop
Types of Sites Typically Surveyed
- Prehistoric Native American Occupation Sites
- Prehistoric Earthworks and Mounds
- Historic Farmsteads and Historic House Yards
- Urban Lots
Geophysics and Archaeology
Geophysical survey is an indispensable component of modern archaeology. It is used to identify subsurface”features,” which are important target resources in both prehistoric and historic-era archaeological sites. Features are important sources of a broad array of archaeological information. Traditionally, archaeologists rely on the use of heavy equipment (including backhoes, earth-movers, bulldozers, etc.) to remove the surface soil to expose and identify features. This traditional approach is time consuming, expensive, and destructive. It is also rarely possible to use mechanical soil removal on a large site-level scale. With our geophysical instrumentation, it is possible to locate and map archaeological resources on a massive scale. Recent OVAI geophysical surveys have exceeded 100 acres in size.
OVAI employs a variety of geophysical instrumentation to identity and map ancient earthworks (Ohio’s grandest prehistoric cultural resource), thermal cooking facilities, burials, house/shelter foundations, and a variety of pit features. It is also useful for the identification of historic-era foundations, cisterns, wells, cemeteries, cellars, privies and other types of features commonly found at 19th-century rural farmstead and urban sites.
OVAI archaeologists use geophysical surveys to pinpoint buried archaeological resources before beginning our excavations, which are typically done by hand. Our combination of geophysical survey and strategically placed hand excavation units has many benefits, both in terms of cost and site preservation:
- Cost and time effective: Geophysical surveys allow us to map the subsurface properties of entire archaeological sites, as opposed to small machine-excavated surface soil removal blocks. Typical surveys can be completed in a few days and the results can be used to target specific features, as opposed to “hoping” to encounter a feature or two with mechanical surface soil removal. Our geophysical approach, combined with focused had excavation, yields far a more comprehensive understanding of a resource than the traditional approach.
- Failure to identify buried cultural features is minimized: The use of heavy machinery on archaeological sites is expensive, time consuming, destructive, and sometimes difficult to organize since it can be difficult to find experienced operators. On Phase II-level archaeological site assessment projects, the use of heavy machinery often fails to yield buried archaeological resources because of limitations in the size of area that can be excavated (mostly due to cost and time). Failure to identify features with this approach is often a failure of the method. This type of failure can be mitigated with reasonable confidence using site-level geophysical survey.
- Geophysical survey is also useful as a planning tool in advance of, or in the absence of, Phase I surveys. Our technology can cover large-acreage surveys with reasonable time and cost.