Sains Malaysiana 32: 13-23 (2003)                                                                                                  Sains Bumi /

Earth Science

Penggunaan Kaedah Seismos Pantulan Cetek

untuk Mengesan Struktur Subpermukaan

(Application of shallow seismic reflection method to

investigation subsurface structures)

Umar Hamzah, Abdul Rahim Samsudin & Abdul Ghani Rafek

Program Geologi

Pusat Pengajian Sains Sekitaran dan Sumber Alam

Fakulti Sains dan Teknologi

Universiti Kebangsaan Malaysia

43600 UKM Bangi, Selangor D.E., Malaysia

ABSTRAK

Beberapa hasil kajian dibentangkan dalam kertaskerja ini untuk menunjukkan bahawa kaedah seismos pantulan cetek sangat berpotensi dalam penyiasatan struktur subpermukaan daripada kedalaman 10 meter hingga 200 meter. Keratan seismos sepanjang 1.7 km di kawasan Banting telah berjaya menonjolkan kehadiran satu lembangan endapan Pleistosen yang menindih Formasi Bukit Kenny. Kedalaman lembangan ini adalah sekitar 200 meter di bahagian barat dan sekitar 75 meter di bahagian timur. Kehadiran satu palung tertimbus pula telah berjaya ditafsirkan dalam satu survei yang dilakukan di delta Pahang, Pekan dengan kedalaman dasar palung sekitar 100 meter dan kelebarannya sekitar 150 meter. Survei di kawasan yang telah mengalami amblesan di Bau, Sarawak telah berjaya menunjukkan kehadiran lubang benam pada kedalaman 10-15 meter yang mempunyai kelebaran sekitar 20 meter. Lubang benam tersebut dipercayai terbentuk oleh kawalan sesar.

ABSTRACT

Presented in this paper are some results showing the potential of shallow seismic reflection technique in investigation of subsurface structures at depth between 10 to 200 metres. A seismic section obtained from a survey along 1.7 km line in Banting area displayed the presence of a basin filled with Pleistocene sediments overlying the Kenny Hill Formation. The depth of the basin in the western part is about 200 metres while in the eastern part is about 75 metres. A buried old river channel was detected in a survey carried out on Pahang delta in Pekan with the depth of the base of the channel is about 100 metres and the channel width is about 150 metres. The presence of a sinkhole was detected through a survey carried out in the vicinity of Bau limestone, Sarawak. The depth of the fault-controlled sinkhole is about 10-15 metres with a width of approximately 20 metres.

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