Application and Validation of High‐Density Electrical Resistivity Tomography in the Investigation of Ancient Tombs Affected by Looting

ABSTRACT In karst terrains underlain by lateritic cover, the inherent resistivity ambiguity between natural cavities, water‐bearing conduits and man‐made tomb spaces poses a fundamental challenge to noninvasive archaeological prospection. 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 ultrahigh‐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. Natural groundwater‐bearing karst conduits were identified as extensive deep low‐resistivity zones, differentiated from anthropogenic structures by their lateral continuity and absence of geometric boundaries. Field excavation confirmed the ERT interpretations: two looting cavities, a well‐preserved single‐chamber tomb structure, and the absence of internal water accumulation all matched the geophysical model. By resolving the ambiguity between anthropogenic structures and karst features and verifying interpretations through excavation, this study establishes 2D ERT as a reliable noninvasive tool for karst archaeological prospection.