Geomagnetometry for Archaeology

In past decades, magnetic surveying had become popular as one of the most effective techniques supporting archaeological prospecting. This is possible because the existence of susceptibility contrasts between the cover soil and several buried finds often causes detectable anomalies. More recently, great advances were made in signal enhancement and boundary analysis of potential field anomalies, thanks to methods allowing a suitable differentiation of the field without making the process unstable. New three-dimensional (3D) imaging techniques provided an estimate of the magnetization distribution within the subsoil by means of high-resolution images of the source distribution. Most of these methods are fast and reliable in the presence of shallow and compact sources, just as in the case of the sources usually occurring in archaeological prospecting. Nevertheless, great effort was spent by the scientific community to overcome serious problems causing low signal-to-noise ratio in the measurements. This chapter provides a step-by-step description of technical solutions adopted to improve the quality of data and to perform a better interpretation of the magnetic anomalies usually associated to the presence of archaeological finds. To this end, a summary of case histories is illustrated giving a general framework of the latest progress in archaeo-magnetism.

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