Geological structure, sedimentation conditions, and petroleum potential of sedimentary basins in Southeast Asia

Sedimentary basins located in the continent-to-ocean transition zones with an active tectonic regime are extremely different in terms of both geological structure and composition of rocks with the hydrocarbon-hosting potential. Oil-and-gas fields in such zones are confined not only to the deltaic, coastal-marine, and submarine-slope sandstones, as well as limestones and dolomites of buried carbonate banks, but also to silicic and volcanic rocks. Such fields have been discovered in weathering crusts of granite plutons, metamorphic rocks of the basement, fissured basalts, and other magmatic rocks. This is demonstrated vividly by the Southeast Asia region, including Indonesia, Malaysia, Vietnam, Bangladesh, and other countries, where fore-arc, back-arc, inter-arc, and marginal-rift sedimentary basins are assigned to petroliferous areas.