Magnetic Gradient, aka Magnetometers

Magnetometers are the most versatile of the geophysical instruments available to archaeologists. They are high portable, very fast, and sensitive enough to detect even very subtle prehistoric Native American features thousands of years old. While some might argue that magnetometers are not as useful on historic-era sites because of all the magnetic clutter at these sites, in reality magnetic surveys can be quite revealing at most kinds of historic sites, including urban and industrial sites.

Examples of Magnetic Gradient Surveys   Prehistoric Native American Camp Sites Prehistoric Native American Villages Prehistoric Native American Earthworks and Mounds Historic Graves and Cemeteries Historic Farmsteads Other Historic Buildings and Settings Urban Lots Industrial Sites

Fluxgate Gradiometer (a type of magnetometer) made by Geoscan Research. Survey in Old Washington Cemetery, Washington Court House, Ohio.

How Magnetic Gradient Surveys Work