Jornal de Geologia e Geofísica
Acesso livre

Abstrato

Application of 2D Resistivity Imaging and Seismic Refraction Tomography to Identify Sungai Batu Sediment Depositional Origin

Saad R*, Muztaza MN, Zakaria MT and Saidin MM

Geophysical survey such as 2D resistivity imaging and seismic refraction tomography are non-destructive methods that widely used in subsurface exploration including archaeological study. The purpose of this survey is to identify the sediment deposition types of Sungai Batu area for Ancient River. Two study sites were chosen to conduct 2D resistivity imaging and seismic refraction tomography surveys. The 2D resistivity imaging survey was conducted using Poledipole array with 2.5 m minimum electrode spacing while seismic refraction tomography was performed using 5 kg sledgehammer as seismic source with 5 m geophone spacing. Roll along techniques are apply for the two methods in the study site 1 and 2. The study concludes that the subsurface of the study area comprise of 3 major soil types. The top soil (1st type) consists of loose and dry alluvium which indicated with resistivity value of >100 Ohm.m. The second type was saturated alluvium (clay and sand) with resistivity and velocity values of 10-50 Ohm.m and <1400 m/s respectively. When this type of soil change to moist condition, the resistivity value increase to <100 Ohm.m but velocity value remain. The 2D resistivity imaging and seismic refraction tomography detected the river bed with the value of >300 Ohm.m and >3600 m/s respectively. The correlation of 2D resistivity imaging and seismic refraction tomography show that the depositional environment for this survey is causes by land sediments deposit.