Structure Styles And Characteristics Of Over Thrust In Western Xuefeng Mountain, Hunan Province

Xuefeng Mt. tectonic zone is located at western Hunan province. Mesoproterozoic Lengjiaxi and Neoproterozoic Banxi groups, the basement of the South China Block, are the mainly exposed rocks in this area. Previously studies has documented a thickened overthust fault system resulting in the Banxi group northwestward over Paleozoic to Mesozoic, however, the structural style and forming mechanism of the overthrust are still unclear. We carried out an extensive field work and mapping program within this area. In this thesis, we describe several geological sections with detailed geometrical data and kinematic senses, which show clearly the Xuefeng Mt. tectonic zone has undergone two stages of deformation. F irst deformation is repesented by the abnormal faults, stretching lineation and fold, show the NW-direction compression. This deformation was later modified by the Banxi group northwestward thrust Paleozoic to Mesozoic, this deformation is repesented by the SE-direction thrust faults and klippes within the northwest of Xuefeng Mt. tectonic zone. Further, we suggested a tectonic model to interpret forming process of this overthrust fault system, and it's implications for the Mesozoic tectonic evolution of South China Block.