What Are You Looking For:

Applications

Features a Ground Penetrating Radar (GPR)
survey can locate:

• Graves
• Water table
• Pits, trenches, voids
• Stratigraphy
• Occupation surfaces
• Walls, floors, foundations
• Metal objects
• Corrosion in structural materials
• Modern utilities

Ground Penetrating Radar survey being conducted in Baja, California. SIR System-2000 with 200 MHz antenna and survey wheel.

Features a Magnetic
survey can locate:

• Ferrous materials
• Fire materials such as brick, roof tiles, kilns, hearths, burned daube
• Middens, pits, trenches, activity areas and graves
• Structural features such as walls, floor surfaces, foundations
• Soil differences
• Modern utilities

Magnetrometry survey being conducted at the Monticello Estate.

Features Resistivity and
Conductivity can locate:

• Compacted surfaces
• Graves
• Trails and pathways
• Structural features such as walls, floor surfaces, foundations
• Differences in soil compaction
• Modern utilities

Electromagnetic survey with the GEM-300 being conducted in Baja, California.

Things to think about when considering a geophysical survey:

Note: Successful geophysical survey is dependent upon a number of factors including: soils, archeological features, methods chosen and user experience.

Physical surface area of survey area:

• Topography
• Ground cover
• Surface structures, roads, fences
• Overhead powerlines
• Recent history of land use

Sub-surface of survey area:

• Soil type
• Underlying geology
• Drainage and soil saturation
• Conductivity of soil (see below for Table of Examples)
• Dielectric permittivity of soil (see below for Table of Examples)
• Tree root systems
• Bioturbation

Archeological characteristics of site:

• Suspected buried features (walls, pits, floor surfaces, graves, tombs, etc.)
• Expected depth to features
• Approximate dimension of features
• Physical properties of features (limestone foundations, humic-rich pit fill, 18th century burial with iron nails and possible grave goods, etc.)
• Site occupation history up to present land use

Approximate Values of Conductivity and Dielectric Permittivity: