Crucial Archaeological Findings using Electrical Resistivity in Malaysia
Electrical resistivity method is a non-destructive which applied in geo-subsurface in identification of characteristic of subsurface profile and buried features for archeological imaging prospect. 2D electrical resistivity method is eco-friendly for environmental study and one of the most sensitive geophysical methods for monitoring changes of electrical properties in the subsurface. There are two well-known archaeological sites in Malaysia’s prehistory which are Bukit Bunuh, Lenggong (Perak) and Sungai Batu, Lembah Bujang (Kedah). 2D electrical resistivity method has been conducted at both site to identify meteorite impact at Bukit Bunuh and archaeological buried features at Sungai Batu. Bukit Bunuh has become significant archaeological site due to the discovery of scattered suevite rocks which is commonly associated with meteorite impact. Total of fourteen 2D electrical resistivity survey lines conducted at Bukit Bunuh using Pole-Dipole array with 5 m minimum electrode spacing. The resistivity results were refining using documented borehole records. The result shows that the area consists of two main zones which are granitic bedrock and overburden. The first layer is granitic bedrock with resistivity value of >1500 Ωm and the second layer is overburden with resistivity value of 10-800 Ωm. Suspected uplifts were detected due to the high impact of meteorite impact. Another archaeological site is located at Sungai Batu which is believed to be the earliest civilization in Malaysia. In this site, it aims to identify the characterization and anomalies in the subsurface. Total of fifteen 2D electrical resistivity lines using Pole-Dipole array with a minimum electrode spacing of 0.75 m. The results were processed with RES2DInv and RES3DInv shows that the anomalies with resistivity 400-500 Ωm and varies from 0.34-1.17 m depth. Few interesting anomalies also detected at depth 2-4 m. Based on the previous study, anomalies were interpreted as baked clay bricks. The result shows potential existence of buried features in the subsurface. Results obtained from these sites using 2D electrical resistivity method give reliable interpretation for crucial archaeological interest.
Index Terms- Electrical resistivity, Meteorite impact, Archaeological, Bukit Bunuh, Sungai Batu