Determining the age of the folding process of folded structures based on restorated cross-sections, Zagros folded and thrust belt, central Lurestan region, southwest Iran


1 Department of Sedimentary Basins and Petroleum, Faculty of Earth Sciences, Shahid Beheshti University, Tehran, Iran

2 National Iranian Oil Company, Exploration Directorate

3 National Iranian Oil Exploration


The study area is located in the central Lorestan Zone, in the simply folded belt of the Zagros folded and thrust belt in the southwest of Iran. This research wants to combine surface and subsurface data, exploration well data and interpreted seismic profiles to construct the cross-sections. Then, based on them, the history and deformation patterns of the geological structures are investigated. They cuts the structures in northeast-southwest direction including Sefidasht, Zangul, Pusht-Jangal, Amiran, Sarkan, Sultan and Malehkuh and a part of Kabir kuh. They were balanced and restoreted. The investigation of the cross-sections shows that the difference in the folding of layers along the cross-sections is due to the change in the folding style in the lateral and vertical directions. The age of the folding process in the Sefidasht, Zangul, Pusht-Jangal, Amiran, Sarkan and Sultan anticlines is Paleocene, but in the Kabir kuh anticline is Oligocene-Miocene. It seems that the difference in the time of the folding process can be attributed to the changing facies in the sedimentary sequences along folded structures. In addition, the mechanical stratigraphy of the sedimentary sequences have been acted different during the folding process. The activity of lower Paleozoic (basal detachment horizon), Jurassic and Lower Cretaceous (middle detachment horizon) and Paleocene flysch sediments (upper detachment horizon) has caused structural changes in the folding geometry. The mechanism of folded structures are fault-related folds and are distinctly of the detachment fold. The total shortening along the cross-sections is equal to 25.6% to 27%.


Main Subjects

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