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_Journal of Structural Geology 32 (2010) 781e791_ _Contents lists available at ScienceDirect_ _Journal of Structural Geology_ _journal homepage: www.elsevier.com locate jsg_ _Structural analysis of the coseismic shear zone of the 2008 Mw 7.9 Wenchuan earthquake, China_ _Aiming Lin a,b,*, Zhikun Ren a, Yasuhiro Kumahara c_ _a Graduate School of Science and Technology, Shizuoka University, Shizuoka 422-8529, Japan_ _b Institute of Geosciences, Faculty of Science, Shizuoka University, Shizuoka 422-8529, Japan_ _c Faculty of Education, Gunma University, Gunma 371-8510, Japan_ _article info_ _Article history: Received 17 September 2009 Received in revised form 18 April 2010 Accepted 12 May 2010 Available online 20 May 2010_ _Keywords: 2008 Mw 7.9 Wenchuan earthquake Longmen Shan Thrust Belt Coseismic shear zone Cataclastic rocks Tibetan Plateau_ _abstract_ _Field investigations reveal that the surface rupture of the 2008 Mw 7.9 Wenchuan earthquake, China, occurred along a pre-existing shear zone in the Longmen Shan Thrust Belt. Structural analyses of the coseismic fault zone and fault rocks show that i) the main coseismic shear zone consists of a fault core that includes a narrow fault gouge zone of <15 cm in width (generally 1e2 cm) and a fault breccia zone of <3 m in width, and a wide damage zone of >5 m in width that is composed of cataclastic rocks including fractures and subsidiary faults; ii) the foliations developed in the fault core and damage zones indicate a dominantly thrust slip sense, consistent with that indicated by the coseismic surface rupture; and iii) coseismic slip was largely localized to within a narrow fault gouge zone of <2e3 mm in width. The structural characteristics of the coseismic shear zone and cataclastic rocks indicate that the location of coseismic slip zone associated with the 2008 Wenchuan earthquake was controlled by a pre-existing shear zone and that the main active fault of the Longmen Shan Thrust Belt has moved as a thrust since the formation of cataclastic rocks along the fault during the late Miocene or early Pliocene._ _© 2010 Elsevier Ltd. All rights reserved._ Ключевые слова: e, r, o