Method Descriptions

Ground-Penetrating Radar

Ground-penetrating radar is an active geophysical method that transmits electromagnetic energy waves into the ground and measures reflections off of interfaces between different subsurface properties. Since archaeological features typically have different physical or chemical compositions than their surrounding soil matrix, they will cause an energy wave reflection. Oftentimes this geophysical method is preferred as it collects data in three dimensions, allowing an archaeologist to measure both the vertical and horizontal extent of an archaeological feature.

Long Swamp GPR

Magnetic Gradiometry

Magnetic gradiometry is a passive geophysical method that measures and maps how the earth’s magnetic field interacts with subsurface magnetic fields. Past activities related to archaeological sites, particularly burning or concentrations of top soil, leave behind magnetic traces that are identifiable using this method. Archaeological feature types that are often distinguishable in magnetic gradiometry data are ditches, hearths, storage pits, and structural foundations. One major benefit of this method is relatively fast survey speed compared with other geophysical methods.

Douthi

Electrical Resistivity

Electrical resistivity is an active geophysical method that introduces an electrical current into the ground and assesses how resistant the soils are to allowing the current to pass though. As with the other two methods, it is dependent upon soil conditions and the types of buried archaeological resources. Electrical resistance varies between types of soil and archaeological features. For example, a grave that retains moisture will be less resistive to an electrical current than a stone foundation wall.

Chattooga Res Mag

Historic Periods

Paleoindian Period (12000-8000 B.C.)

Archaic Period (8000-1000 B.C.)

Woodland Period (1000 B.C. – 1000 A.D.)

Mississippian Period (1000 – 1540 A.D.)-

Historic European Period (1540 A.D. to Present)

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