Bulletin of the Geological Society of Malaysia, Volume 35, July 1994, pp. 61-68
Jabatan Geologi, Universiti Kebangsaan Malaysia, 43600 Bangi, Selangor D.E.
Abstract: Twenty boring logs were studied in conjunction with four shallow seismic reflection data. The boreholes located close to the seismic lines were drilled at depths ranging from 12 to 40 metres. By comparing the borehole data with the seismic record, empirical relationships between the character of the seismic records and the corresponding lithology was established. The seismic data were analysed using a velocity of 1,600 m/sec to convert the two way travel times into depth. Four distinct lithological units were recognized and classified into units A, B, C, and D.
The uppermost unit, D representing soft clay with some coarse sand is characterized by strong horizontal stratification on seismic profiles. Unit C which is made up of medium to coarse sand with some clay and shell fragments is recognized by a chaotic reflection pattern in seismic records. Unit B is represented by dense silty sand with numerous mica flakes and it is interpreted as weathered granite. The lower most unit A comprises lowly weathered to fresh coarse grained granites or bedrock and shows up as a domed reflection pattern on seismic sections. Using these empirical relationships, all the four seismic profiles were interpreted and analysed.