Geology and groundwater exploration in limestone using electrical resistivity imaging (ERI) at Kampung Star Baru, Gua Musang, Kelantan

The study area lies between coordinates N 5° 2'4.17" to N 4°59'17.27" and E 102° 0'3.37" to E 102° 0'0.38" with an area of 25 km². The study area is rural, consisting of oil palm plantations, a rubber estate and a primary forest. This study aimed to produce a geological map of the area on a scale of 1:25 000 and to investigate the groundwater sources using Electrical Resistivity Imaging (ERI) method. The purpose of geological mapping is to map the lithology, geological structure and geomorphology using the traversing method and collected groundwater potential data using ABEM Terrameter LS. The field data collected was then processed in GIS software platform to generate geological map and Res2DInv software to give pseudo section data of groundwater potential. The lithology in the study area was composed of limestone, quartzite, slate, shale, and interbedded mudstone with siltstone rock. The geomorphology in the study area is surrounded by hilly areas and karst formation with the elevation ranging from 100 metres to 460 metres. Limestone rock were majority found at the study area. The meta-sedimentary rocks like shale, slate and interbedded mudstone with siltstone were found at the East to South of the study area. In structural geology, outcrop found have have anticlines features folding, faults, bedding and joints in the study area. Bedding is continuous at several outcrops and hills. The strike and dip data collected were analysed in a rose diagram and stereonet to plot the orientation of discontinuities. The drainage patterns found in the study field are parallel and have minor dendritic patterns. This research is conducted by doing geological mapping and specification resistivity surveys. The Pole-dipole configuration array is used to perform four survey lines of 200 m inside the study area. The processed resistivity data has an RMS error of less than 20%. The study also found that the highest groundwater potential was located within the fractured bedrock of sedimentary rock.