Out‐of‐Sequence Backthrusting Since the Middle Pleistocene Revealed by the Jiangnanmiao Thrust Fault Along the Northern Tian Shan, China

Abstract

The tectonic wedge model describes a triangular-shaped structure, which has a duplex geometry and contains completely opposite thrusting vergences within a triangle zone (e.g.

Retracted: Control of Multiple Detachments on Structural Development in the Southern Junggar Fold‐and‐Thrust Belt, Northern Tian Shan: Implications for Seismic Hazard Assessment

“…From Taxi River to Jingou River, the E 2–3 a is under overpressure (Luo et al., 2007), acting as the shallow detachment. Figures 11c and 11d synthesize the kinematic models of these structures (e.g., Guan et al., 2016; Hu et al., 2021; Stockemeyer et al., 2014). However, near the western termination of the Huoerguosi anticline in the middle sector, the SJT turns into a simple, buried south‐dipping thrust ramp, where the flat associated with the Paleogene detachment is absent on Line E‐E′ (Figure 5a).…”

“…During this process, we mainly focused on the development of basinward‐vergent thrusts and neglected back‐thrusts and other secondary faults (Figure 10), and aimed to demonstrate the influence of lateral variations in detachment levels on the kinematic evolution of main structures (Figure 11) and its implications for seismic hazard assessment (Figures 12 and 13). However, it is also worth to note that some back‐thrusts are currently active, accommodating horizontal shortening (e.g., Hu et al., 2021).…”

“…Line E‐E′ (Figure 5a) across Nananjihai anticline, western termination of Huoerguosi anticline and Anjihai anticline is characterized by the south‐dipping SJT as a simple fault ramp without upper flat unlike its counterpart in the east (e.g., Hu et al., 2021; Guan et al., 2016; Stockmeyer et al., 2014). The SJT roots from the basement and terminates within the Pliocene Dushanzi Formation (N 2 d) as constrained by fault cutoffs shown on seismic image (Figure S3a).…”