Supplementary material from " Application and validation of high-density electrical resistivity tomography in the investigation of ancient tombs affected by looting"

This study employed two-dimensional electrical resistivity tomography (ERT) with a Wenner-α array to investigate an ancient Ming-dynasty tomb in the karst terrain of Guilin, China.

Three parallel survey lines were acquired and processed using robust 2D inversion in RES2DINV. The results reveal a diagnostic resistivity signature for looting disturbance: paired ultra-high-resistivity anomalies (air-filled voids) overlying low-resistivity anomalies (water-saturated clay infill), consistently observed across all three profiles. The brick-and-stone masonry tomb chamber, located at approximately 3 m depth, produced continuous high-resistivity anomalies distinguishable from adjacent gravel fills and rammed-earth retaining walls.