Pull-apart basin geometry in three dimensions has been widely known, but the evolution and kinematics of its formation is very difficult to understand well. That is because the formation is controlled by the condition of the basement so often the area becomes very complex. However, in many cases is difficult to analyze using subsurface data due to the poor seismic image quality as a results of complex deformation style, either at the time of exploration and development. Therefore, a special technique is needed in understanding and solving problems related to it. This paper will show restoration results using sandbox analogue modeling and kinematics to analyze the evolution of pull-apart basin formation in three dimensions.
Various sandbox analogue modeling results have been published so it has become an important technique in the field of geology, especially the geological structure. In the analogue sandbox modeling, the initial state before deformation can be compared with the state after deformation. This comparison is an important part in understanding the evolution of structures. Therefore, this method can describe a deformation style and structural evolution of the sedimentary basin. In this study, apparatus designed specifically for modeling strike-slip fault system and complex deformation. The dimensions of the box are sufficiently large to ensure that a large part of the model escapes boundary effects. The sand pack is made of thin alternating colored layers, which allow the identification of faults and folds on cross-sections as well as a map view. In this study, we used natural dry quartz sand with a Navier-Coulomb rheology and angle of internal friction of about 30o. In addition, it is also used wooden blocks to represent the rigid material that does not change shape during the deformation process.
From the results of this study demonstrated that sandbox analogue modeling is a systematic and effective method to study the evolution and kinematics of the pull-apart basin formation in three dimensions. Of this study also demonstrated that one of the very influence the geometry of a pull-apart basin is a condition of essentially pre-basin rocks are formed.
Authors : Meli Hadiana, Benyamin Sapiie, Agus Handoyo Harsolumakso