Integrated Geophysical Methods for Detecting Archaeological Han Dynasty Tombs

Abstract

A group of Han Dynasty tombs were found in Nanchang, Jiangxi Province, China, close to Poyang Lake. To investigate the coffin chambers, tunnels, burial pits, and remains of the tomb, a reconnaissance survey was carried out using integrated geophysical methods, including a ground magnetic survey, a self-potential (SP) survey, electrical resistivity tomography imaging, and ground penetrating radar (GPR).

A survey area measuring 85 m east to west and 120 m south to north completely contained the grave mounds. The survey grid was 5 m spacing in the east-west direction and 2 m spacing in the south-north direction. Positive anomalies in the magnetic field readings corresponded to the burial pits and the rammed foundation. A high SP value corresponded to the surface projection of the coffin chambers and tunnels, and also to the collapsed mausoleum building. Inversion of the multi-electrode resistivity data showed the positions of the coffin chambers, funeral pits, and tunnels very well. 2D and 3D resistivity inversion showed that tombs and burial pits have relatively low resistivity, because they lie below the groundwater table and relative to the surrounding soil contain more water.

Furthermore, the entry ramps have relatively high resistivity. GPR signals did not have good penetration because of the low-resistivity moist surficial soil, and thus could not detect the chamber and tunnels, but revealed clearly the modern tombs and building foundations that lie near the ground surface.