Application Guide
Geophysical Equipment for Archaeological Prospection
Geophysics lets archaeologists map buried ditches, walls, kilns and graves across whole landscapes before — or instead of — excavation.
Archaeological prospection is non-destructive by design. Different features contrast with their surroundings in different ways: fired features and organic-rich ditch fills are magnetic; stone walls and rubble are resistive; voids, floors and layers reflect radar energy. The most informative surveys combine two or more methods.
Magnetic gradiometry is usually the first-pass method because it covers several hectares per day; GPR and electrical methods then add depth and structural detail over the areas of interest.
Methods Compared
| Method | Detects | Typical Depth | Limitations |
|---|---|---|---|
| Magnetic gradiometry | Ditches, pits, kilns, hearths, burnt features | Typically top 1–2 m | Ferrous debris and igneous geology create noise |
| Ground penetrating radar | Walls, floors, voids, graves, stratigraphy (3D depth slices) | Typically 0.5–3 m | Limited in wet clay; slower coverage than magnetometry |
| Earth resistance / ERT | Stone walls, rubble, ditches, moisture contrasts | Shallow (resistance) to several metres (ERT) | Needs electrode contact; slower |
| EM conductivity / susceptibility | Soil changes, ditches, magnetic susceptibility | Selectable by coil spacing | Lower resolution than gradiometry for small features |
Depths are typical field values — actual performance depends on ground conditions, target size and survey design.
Landscape scale vs site scale
Cart-based multi-sensor gradiometer and 3D GPR systems now make landscape-scale surveys realistic, covering many hectares at high resolution. For individual sites, hand-carried gradiometers and single-channel GPR remain the most cost-effective tools, and multi-coil EM instruments map soil and susceptibility variations in the same pass.
Recommended Instruments
A selection from our catalog. We source many more models — tell us what you need.
Which Condition Tier?
Universities and heritage bodies often stretch budgets with Refurbished or Absolute Certified gradiometers and GPR, reserving New for flagship systems. Legacy instruments sourced as Surplus are well suited to teaching and field schools.
See the condition tier guide for what New, Refurbished, Absolute Certified and Surplus each include, or the industries overview for related sectors.
Frequently Asked Questions
What is the best geophysical method for archaeology?
There is no single best method. Magnetic gradiometry is the usual first choice for speed and sensitivity to ditches and burnt features; GPR adds depth and structure; resistance and EM help where features are stone or moisture-related.
Can GPR find graves?
Often, yes — GPR can detect grave cuts, coffins and vaults through changes in soil disturbance and voids, though results depend strongly on soil type and moisture.
Do you supply equipment for university field schools?
Yes. Refurbished and Surplus gradiometers, EM meters and GPR units are a cost-effective option for teaching, and we can quote complete kits.
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