The Neogene deformation, unconformity surfaces and uplift features in delta tectonics, Tarakan sub basin
Proceedings, Indonesian Petroleum Association, Forty-Third Annual Convention & Exhibition, September 2019
Hade B. Maulin, Benyamin Sapiie, Indra Gunawan
The Tarakan Sub basin is located in North East Kalimantan, several kilometers to the north from the famous Kutai Delta. As one of prolific basin in North Kalimantan, Tarakan Sub Basin is very attractive yet less explored. To the north, The Tarakan Sub basin is bounded by The Samporna Faults and to the south it is bounded by Mangkalihat Faults. Those regional faults are interpreted as sinistral strike slip that creates high morphological features known as Samporna High and Mangkalihat High. The unique setting of both boundaries give speculative ideas of what happen in the area.
The Tarakan Delta is different in some aspects to the famous Kutai. The structural and stratigraphy of the basin gave signatures to the model of Tarakan delta tectonics. Regional sedimentology knowledge helps to answer various possibilities of sedimentation process and hence, their influence to growth fault mechanism. Structural geology analysis hold an fundamental key to the basin deformations and so sedimentation process.
Some data of wells and 2D/3D seismic lines are used to observes the unconformity surfaces. Most of unconformity surfaces in Tarakan sub basin are angular unconformity, the one which created by an uplifting process. The occurrence of unconformity surfaces suggest that the area uplifted some periods in geologic time and can also pointed structural reactivation or tectonic rejuvenation. Structural reactivation in Tarakan sub-basin is one of main contributor to control depositional from fluvial to delta system, a geological marks to the migration process, and also be a rude way to lost hydrocarbon accumulation.
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