The third is the Longmenshan transitional tectonic zone, whose shallow layer and deep structure are characterized by an electrical structure with a thrust nappe towards the east, and a high-conductivity material extending to the lithospheric mantle, respectively.
One is the plate extrusion model, which postulates that the crustal uplift process was caused by deformation of brittle material within the crust that arose from the thrust nappe effect (Tapponnier et al.
The amount of uplift for the Sichuan--Yunnan block reached 1,180 m (Zhang, 2004), with many highly-angular thrust nappe tectonic structures appearing in the Longmenshan--Jinpingshan orogenic zone.
This accumulated material is the material basis and key factor behind the tectonics of the QTP's eastern margin, which includes crustal thickening, geomorphic uplift, and formation of thrust nappe structures in the orogenic tectonic zone.
The Dabashan thrust nappe structure at the southern margin of the Qinling orogenic belt suffered at least two stages of evolution which are Late Triassic plate subduction collisional orogeny between North China block, Qinling micro-plate and Yangtze block followed by intracontinental orogeny since the Meso-Cenozoic.
Keywords: Numerical modelling; South Qinling; Bashan Arc; Dabashan; Thrust nappe structure
The Dabashan thrust nappe structure is one of major characteristics of Qinling orogenic belt.
The Bashan Arc is one of key factors to understand the geodynamic evolution of the Dabashan thrust nappe structure.
This paper presents a numeric modelling using Fast Lagrangian Analysis of Continua algorithm (FLAC) to analyse the geodynamic evolution of the Dabashan thrust nappe and the formation of the Bashan Arc, and mainly focuses on above issues.
The Dabashan thrust nappe structure is at the northeastern of the Sichuan basin and the northwestern of the central Yangtze block (Zhang et al.
In fact, it is a thrust nappe belt consisting of a series of NE-SW or N-S thrusts.
2), were supposed as the "anchor" during the formation of the Dabashan thrust nappe structure because of their relative rigid basements (Dong et al.