Characterization Of Lojing Hot Springs, Gua Musang, Kelantan From Geosciences Aspects

Abstract

The study was conducted to identify and determine the relationship between geology, geophysics and geochemistry of the study area. Geophysical surveys were conducted to obtain the sub-surface profile and to relate it with lineament analysis. Based on gravity method analysis, it is interpreted that the study area consists of granite bedrock close to the surface which exhibits high gravity anomalies whereas low density rock areas with high fractures and lineaments exhibit low gravity anomaly values. The electrical resistivity survey shows that the study area is underlain by granite bedrocks which also proves that the origin of the hot springs are non-volcanic as no volcanic activity or rocks can be found around the study area. Resistivity values recorded for granite bedrock exceeded 900 Ωm. Based on the resistivity profile, it is also possible to determine the reservoir zone and fractured zone which shows the resistivity values between 0 Ωm to 250 Ωm. The direction of the lineaments on the resistivity profile together with gravity survey are parallel to the lineament analysis, which is Northeast-Southwest, Northwest-Southeast and North-South. The borehole log data also shows that the study area is underlain by granite bedrock and the hot water source in this area is from confined aquifer. Geochemical and geothermometry analysis were performed on 14 hot water samples. The results of geochemical analysis show that the average elements concentration is as follows; silica 277 ppm, calcium 2.00 ppm, magnesium 0.14 ppm, potassium 2.3 ppm, sodium 29 ppm, iron 0.12 ppm, bicarbonate 41 ppm, sulphate 18 ppm, chloride 1.5 ppm and fluoride 2.9 ppm. The calculation results of quartz geothermometry shows an average temperature of 203°C, while chalcedony geothermometry shows an average temperature of 177°C. The enthalpy for heating water calculated from quartz geothermometry using the Steam Table shows an average of 864 kJ/kg which can be interpreted as a mid-level enthalpy. The geology of the hot springs area shown in the geological map and lineament analysis map proves the relationship with the geophysical survey and borehole log data.