Proceedings, Indonesian Petroleum Association
Thirty-Seventh Annual Convention & Exhibition, May 2013
Gravity tectonics in Indonesia: Petroleum implications
Awang Harun Satyana*
* SKK Migas
Abstract
Gravity tectonics is about tectonic movement due to differential gravity between Earth’s layers or two adjacent areas (primary vertical endogenic force/tectogenesis) and its ensuing gravitational reactions (secondary lateral tectogenesis) . This movement thoroughly concerns with equilibrium or isostatic compensation. The origins of uplifts in the collision zones of Indonesia (Meratus Uplift-SE Kalimantan; Batui Uplift-eastern Sulawesi, Papua’s Central Ranges Uplift , and Timor-Tanimbar Uplift) are satisfied explained by gravity tectonics. In these cases, vertical movement due to isostatic exhumation of once subducted micro-continent/ continent in collision zones provides mechanism for the uplifts. The origins of regional compressive structures such as Samarinda Anticlinorium, eastern Kalimantan, offshore North Makassar toe thrusts, and North Serayu fold-thrust belt, northern Central Java are considered as secondary lateral tectogenesis of gravity tectonics. Their mechanisms of deformation are through gravitational gliding/sliding (gliding tectonics), compensating differential gravity due to hinterlands uplifts. Gravity tectonics is essential in forming some elements and processes of petroleum system. It forms foreland basin; structural traps, mostly thinskinned; and deposition of syn- and post collisional sediments burying sources to depth of oil and gas windows. The paper will discuss some areas in Indonesia with structures related to gravity tectonics and their implications for petroleum accumulation.
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