TECTONOSTRATIGRAPHY OF KHMER BASIN, CAMBODIA

• Main Author: Lanang Bayushakti, Dimas
• Format: Theses
• Language: Indonesia
• Subjects: Geologi, hidrologi & meteorologi
• Online Access: https://digilib.itb.ac.id/gdl/view/41792
• Institution: Institut Teknologi Bandung

Khmer Basin is located at offshore of Cambodia, at 143525-355000E and 973900- 1247500N, 48 (102E-108E) zone. The basin is a potential oil and gas reserve with complex structural setting. The availibility of subsurface data including 2D seismic section (314 section) and drilling data (9 well) support the study to understand basin configuration and it’s stratigraphy setting which it fills basin deposition. The hypothesis are formed by study of regional, it are Khmer Basin is created by the manifestation of regional strike-slip fault, formed at pull-apart system and has a rift basin geometry. Then, the sedimentation pattern is arranged by normal fault at syn rift phase. At post rift, normal fault ceased, the sedimentation is controlled by burial and topography. To prove the hypothesis, research study starts with horizon and structural interpretation from seismic section. The results is used to create depth structure map and isopach map. Analysis of thickening and depletion of strata with validation from balanced section become the main reference to analyze the basin configuration mechanism. From seismic interpretation, study area is divided to 10 horizon: batuan dasar, S2, S3, S4, S5, S6, S7, S8, S9, S10. Structural pattern of Khmer Basin has north-south orientating. Normal fault is the primary structure of the basin, bounded the east and west of basin and control the syn rift sedimentation. Strike-slip fault activate after the primary fault ceased, observed from the strike-slip fault cut a younger strata than the normal fault did. Existence of strike-slip fault is identified from negative flower structure pattern. Khmer Basin has a rhomb-shaped graben, over 6 km thickness of depocenter, asymmetri shaped, with + 30 km of maximum width. Balanced section shows that Khmer Basin through two deformation style, first is extensional (S2), second is shortening (S3-S10). Tertiary tectonic order of Khmer Basin is divided to 4 phase, that are: syn-rift phase (S2), early post-rift (S3-S4), middle post-rift (S5-S8) and late post-rift (S9- S10).