Effect of the perpendicular faults interaction on the Rag Sefid and Tango folds evolution (SW Iran)

Document Type : Original Article

Authors

1 Department of Geology, Faculty of science, University of Birjand, Birjand, Iran

2 Parsian Kish Drilling Company (PKD Co), Tehran, Iran

Abstract

Introduction: Fault interaction creates areas of local concentration of stress and disturbances that affect the geometry and cognitive movement of faults. This stress concentration can create secondary structures in damage. In this article, the influence of the interaction or relationships between the Zagros and Arabian faults in the Zagros foreland on the formation and different geometry of the Rag Sefid and Tango anticlines is investigated and explained.
Materials and methods: Due to the occurrence of the phenomenon of fault interaction between the faults that cause the Rag Sefid and Tengo anticlines, the three-dimensional interaction theoretical models between the fault segments are first introduced. By comparing the geometrical condition of fault parts in the study area with theoretical models, the types of fault interaction in this area are introduced. Finally, due to the dependence of the folds in the region on the fault, and with a detailed study of the geometry and dimensions of the underlying faults, the factors affecting changes in the pattern of folds are examined and the development of folds with different geometries, dimensions, extensions and mechanisms is justified.
Results and discussion: Regarding the length more than 3 times of the Rag Sefid fault respect to the southern part of the Hendijan-Izeh strike-slip fault, the mean slope of 47 degrees of the Rag Sefid fault relative to the Hendijan-Izeh fault of 80 degrees and according to the general compression direction of N22E in the Southwest of Iran and the southern part of the Hendjan-Izeh fault trend (N20E), as well as the Rag Sefid fault trend, which is approximately perpendicular to the general compression direction, the deformation amount of the Rag Sefid fault is more than the Hendijan fault. In this condition, the stress field of the Rag Sefid thrust fault is dominated and due to the less resistance of the rising, folding with a larger amplitude occurs on the the Rag Sefid anticline; so that the folding amplitude in the Rag Sefid anticline is more than twice as large as the Tango anticline, and the tip of the Tango anticline is about 1,200 meters lower than the Rag Sefid anticline.
Conclusion: It can be concluded that in a set of faults where the interaction between the faults has occurred, larger, shallower faults with a plane slope of about 45 degrees, which have a diagonal or vertical orientation compared to the general orientation, they can create large and clearer folds similar to the folds with large dimensions in the Rag Sefid anticline compared to the Tango anticline.

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Abdollahi Fard, I., Braathen, A., Mokhtari, M. and Alavi, S.A., 200. Interaction of the Zagros Fold thrust belt and the Arabian type, deep-seated folds in the Abadan Plain and the Dezful Embayment, SW Iran: Petroleum Geoscience, v. 12, p. 347-362.
Allmendinger, R. and Shaw, J., 2000. Estimation of fault propagation distance from fold shape;
implications for earthquake hazard assessment: Geology, v. 28 (12), p. 1099-1102.
Aydin, A. and Schultz, R.A., 1990. Effect of mechanical interaction on the development of strike-slip faults with echelon patterns: Journal of Structural Geology, v. 12, p. 123-129.
Bastesen, E. and Rotevatn, A., 2012. Evolution and structural style of relay zones in layered limestoneeshale sequences: insights from the Hammam Faraun Fault Block, Suez rift, Egypt: Journal of the Geological Society of London, v. 169, p. 477-488.
Biddle, K.T. and Christie-Blick, N., 1985. Glossary e strike-slip deformation, basin formation, and sedimentation. In: Biddle, K.T., Christie-Blick, N. (Eds.), Strike-slip Deformation, Basin Formation, and Sedimentation: Society of Economic Mineralogists Special Publication, v. 37, p. 375-386.
Bull, J.M., Barnes, P.M., Lamarche, G., Sanderson, D.J., Cowie, P.A., Taylor, S.K. and Dix, J.K., 2006. High-resolution record of displacement accumulation on an active normal fault: implications for models of slip accumulation during repeated earthquakes: Journal of Structural Geology, v. 28, p. 1146-1166.
Choi, J.H., Edwards, P., Ko, K. and Kim, Y.S., 2016. Definition and classification of fault damage zones: a review and a new methodological approach: Earth Society Review, v. 152, p. 70-87.
Curewitz, D. and Karson, J.A., 1997. Structural settings of hydrothermal outflow: fracture permeability maintained by fault propagation and interaction: Jornal of Volcano Geothermal Resarch, v. 79, p. 149-168.
Duffy, O.B., Bell, R.E., Jackson, C.A.L., Gawthorpe, R.L. and Whipp, P.S., 2015. Fault growth and interactions in a multiphase rift fault network: The Horda Platform, Norwegian North Sea: Journal of Structural Geology, v. 80, p. 99-119.
Fossen, H. and Rotevatn, A., 2016. Fault linkage and relay structures in extensional settings e a review: Earth-Sci. Rev, v. 154, p. 14-28.
Harding, T.P. and Lowell, J.D., 1979. Structural styles, their plate-tectonic habitats, and hydrocarbon traps in petroleum provinces: American Association of Petroleum Geologists Bulletin, v. 63, p. 1016-1058.
Maerten, L., Pollard, D.D. and Maerten, F., 2001. Digital mapping of three-dimensional structures of the Chimney Rock fault system, central Utah: Journal of Structural Geology, v. 23, p. 585-592.
Kim, Y.S., Peacock, D.C.P. and Sanderson, D.J., 2004. Fault damage zones: Journal of Structural Geology, v. 26, p. 503-517.
McClay, K.R., Whitehouse, P.S., Dooley, M. and Richards, M., 2004. 3D evolution of fold and thrust belts formed by oblique convergence: Marine and Petroleum Geology, v. 21, p. 857-877.
Nixon, C.W., Sanderson, D.J. and Bull, J.M., 2011. Deformation within a strike-slip fault network at Westward Ho! Devon U.K.: domino vs conjugate faulting: Journal of Structural Geology, v. 33, p. 833-843.
Nixon, C.W., Sanderson, D.J., Dee, S., Bull, J.M., Humphreys, R. and Swanson, M., 2014. Fault
interactions and reactivation within a normal fault network at Milne Point, Alaska: American Association of Petroleum Geologists Bulletin, v. 98, p. 2081-2107.
Peacock, D.C.P. and Sanderson, D.J., 1991. Displacements, segment linkage and relay ramps in normal fault zones: Journal of Structural Geology, v. 13, p. 721-733.
Peacock, D.C.P., Nixon, C.W., Rotevatn, A., Sanderson, D.J. and Zuluaga, L.F., 2016. Glossary of fault and fracture networks: Journal of Structural Geology, v. 92, p. 12-29.
Rowan, M.G. and Linares, R., 2000. Fold-evolution matrices and axialsurfaces of fault-bend folds; application to the Medina Anticline, Eastern Cordillera, Columbia: American Association of Petroleum Geologists Bulletin, v. 84(6), p. 741-764.
Savage, H.M. and Cooke, M.L., 2004. The effect of non-parallel thrust fault interaction on fold
Patterns: Journal of Structural Geology, v. 26, p. 905-917.
Shamir, G. and Eyal, Y., 1995. Elastic modeling of fault-driven monoclonal fold patterns: Tectonophysics, v. 245(1-2), p. 13-24.
Woodcock, N.H. and Rickards, B., 2003. Transpressive duplex and flower structure: dent fault system, NW England: Journal of Structural Geology, v. 25, p. 1981-1992.
Yousefi, M., Moussavi, S.M. and Khatib, M.M., 2021. Analog modeling of faults interaction in the structural evolution of the Rag Sefid and Tango anticlines (SW Iran): Earth Science Research, v. 12, p. 58-73 (in Persian).