Magnetics

Detection of fired features — hearths, kilns, burned structures — and ferrous artefacts including nails, tools and weapons. Thermally remanent magnetisation makes hearths among the strongest archaeological targets. Gradiometry resolves sub-metre features at traverse spacings of 0.25–0.5 m.

Delineation of buried waste extent, depth and internal composition. Ferrous debris generates intense, chaotic anomalies clearly distinguishable from background geology. Combined with EM surveys, magnetics defines both lateral boundaries and internal metallic content of uncharacterised legacy waste.

Unexploded ordnance and underground storage tanks are among the strongest magnetic targets — ferrous casings generate dipolar anomalies detectable at depth. Gradiometry isolates discrete point-source anomalies for targeted excavation in pre-construction clearance on former military and industrial land.

Mapping of intrusive contacts, fault zones, dykes and lithological boundaries where magnetic susceptibility contrast exists. Mafic intrusives and magnetite-bearing units generate broad, high-amplitude anomalies used to extend geological mapping beyond outcrop.

Systematic high-resolution gradiometry for forensic search of buried ferrous evidence — weapons, vehicles, drums and containers. Covers large areas rapidly as the primary screening tool before targeted metal detection or excavation.

Detection of cast iron and steel pipelines, well casings and buried infrastructure — complementing GPR and EM utility locating where pipes are large, deep or obscured by conductive fill. Dipole modelling provides depth estimates without excavation.