Publications

Based on the observations of subsurface and bathymetric maps, various structural patterns are observed in the Tarakan Basin, especially in the Tarakan and Tidung Sub-basins. One of the hypotheses put forward in this study that the gravity-driven mechanism is responsible to generate the normal faults system and folds -thrust belt in the offshore Tarakan Basin. We conducted an integrated study using palinspatic reconstructions of several seismic sections and an analogue-sandbox modeling to observe and explain this gravity-driven. The deformation modeling, which is controlled by gravity requires special conditions that can trigger the movement. The three main parameters that cause gravity deformation to occur are lithology, loading, and slope. In the case of the Tarakan Basin, modeling was carried out by referring to the results of 2D-seismic palinspatic reconstructions. Besides, the additional information as a basis for modeling is also based on the current topographic and bathymetric data. The tectonic reconstruction is used as a reference for paleo-stress data. In theory, one of the factors determining the occurrence of this mechanism is the presence of detachment. This detachment manifests the over-pressure fluid anomaly in the rock, such as over-pressure shale and salt layers. To simulate the conditions that may closely be like the behavior in this detachment, bead materials were selected in the sandbox modeling. Twenty-two experiments were conducted to test the bead as the materials in this modeling, and more than thirty experiments were carried out to model this case. From more than ten realizations, the model with the closest results to seismic interpretation and palinspastic analyses were chosen. From the results of experiments that have been conducted, the development of thrust faults related to the development of normal faults. This evidence is in line with the deformation of gravity-driven mechanism.