BASIN EVOLUTION AREA “MA” TONLE SAP CAMBODIA

• Main Author: RAHMAN, APZIARIEF
• Format: Theses
• Language: Indonesia
• Subjects: Geologi, hidrologi & meteorologi
• Online Access: https://digilib.itb.ac.id/gdl/view/13996
• Institution: Institut Teknologi Bandung

Understanding of onshore Cambodian geology especially in petroleum geology is very limited. It can be seen from limited surface data and no subsurface data. Research area is located in basin margin of Tonle Sap. Due to limited data, geometry, stratigraphy and basin forming process of the area is not well understood. Currently, Tonle Sap basin is interpreted as tertiary pull apart basin. However, based on available geological map, Tertiary rock is not present. There are only Paleozoikum, Mesozoikum and thin layer of Quarternary rock that widespread around Tonle Sap lake present in geological map.<p>In 2008, seismic acquisition has been done in research area. New seismic data is used to explain basin evolution in research area. Steps in this research are studying regional tectonic, defining regional sedimentation cycles, defining stratigraphic sequences and creating isochrone maps. From thickening and thinning of isochrone maps, seismic sections analysis, and flattening, then basin geometry and fault control is interpreted. Based on this step, then defined if the basin formed by extentional rezim or compressional rezim. The basin in research area is Paleozoikum and Mesozoikum basin. From seismic interpretation, there are 5 markers and 5 isochrones that can be identified. Structural patterns in research area are NW-SE and N-S trend. Both in extensional phase (Carboniferous- Middle Triassic) and compressional phase (Upper Triassic-Cretaceous), basin forming is highly influenced by NW-SE faults.<p>In extensional phase, basin development started from rifting, then continue to be passive margin. Passive margin is the lowest basin that can be seen in seismic character, while the previous rift basin can not identified in available data. Extensional phase continued with NE-SW extension until Middle Triassic. Compressional phase started from Late Triassic until Cretaceous marked by high angle angular unconformity continued by foreland/piggy back basin development. Based on available geological map data and limited seismic sections, it can be summarized that there are potential of source rock, reservoir, seal and trap in Paleozoikum and Mesozoikum layer. Furthermore, hydrocarbon potential in research area is encouraging. So, exploration should be continued.