Open Journal of Geology, 2016, 6, 971-981 Published Online August 2016 in SciRes. http://www.scirp.org/journal/ojg http://dx.doi.org/10.4236/ojg.2016.68073 How to cite this paper: Badrkhani, M., Maleki, Z. and Arian, M. (2016) Folding Style Analysis of the Tabnak Sweet Gas Field, Zagros, Iran. Open Journal of Geology, 6, 971-981. http://dx.doi.org/10.4236/ojg.2016.68073 Folding Style Analysis of the Tabnak Sweet Gas Field, Zagros, Iran Marzieh Badrkhani, Zahra Maleki * , Mehran Arian Department of Geology, Science and Research Branch, Islamic Azad University, Tehran, Iran Received 21 January 2016; accepted 27 August 2016; published 30 August 2016 Copyright © 2016 by authors and Scientific Research Publishing Inc. This work is licensed under the Creative Commons Attribution International License (CC BY). http://creativecommons.org/licenses/by/4.0/ Abstract The Zagros fold-thrust belt in Iran is home to one of the enormous petroleum producing reser- voirs in the word. The Tabnak gas field in this belt is one of the enormous sweet gas fields that discovered on the land. This anticlinal structure is located in the Coastal Fars sub-basin and is bounded from North by the Varavi gas field, from South by the Kuh-e Madar anticline, from East by Assaluyeh gas field and from West by Kuh-e Dehnow anticline. Its length is about 80 km and width is about 15 km. This structure is asymmetric anticline and is located with irregular near the Assaluyeh gas field. The Tabnak gas field is deepest structure between anticlines in the Coastal Fars area. This gas field has a special place for accommodating the enormous Hydrocarbon re- sources and for this reason, it is very important for Iran country. In this structure, the Dashtak, Kangan and upper Dalan Formations have Hydrocarbon. Analysis and description of fold style elements are essential for structural studies. Based on this case, the comparison of the fold styles and folding mechanism is possible. The main aim in this research is the analysis of the fold style elements of the Tabnak anticline for determining the folding pattern and tectonic regime on this structure. This case has very important for Hydrocarbon exploration between gas fields in the Fars area. In this research, we used the Tectonics FP software, Global Mapper software and geo- logical maps and reports of Iranian National Oil Company. In addition, we used common classifica- tion of fold for indicating folding mechanism of the Tabnak anticlinal structure. Based on analysis of the fold style elements, the Tabnak anticlinal structure has variation in fold style. This structure has three different fold styles in different parts. The changes of fold axis, axial plane characteris- tics and fold classification confirmed several fold styles in different parts of the Tabnak anticline. These changes are observed specially in B-B', F-F' and G-G' sections of this anticline. It seems that these parts have been suffered more deformation in the study anticline. In addition, based on in- terlimb and folding angle, fold type is close type in all of parts. The close type required more ac- curacy, because the close type may be ensigns of complication regime. In the study area, G-G' and F-F' section of the Tabnak gas field probable show folding style changes have been affected by Gavbandy Paleo-high. * Corresponding author.