Constraints on deformation kinematics across the Yumu Shan, NE Tibetan Plateau, based on fluvial terraces

摘要: Abstract In compressive ranges, the kinematics of thrusts and related folds are key to understanding mountain building processes; however, relatively little attention has been paid folding on hanging-wall a thrust fault which broken surface. On Yumu Shan fault, lies north side at NE edge Tibetan Plateau, we found that significant deformation had occurred simultaneously with faulting To determine faulting, surveyed deformed fluvial terrace surfaces across fold fault. The geometry surface T4 Liyuan River exhibits displacement 55 ± 11 m trace, while in hinterland, there is an active anticline wave length ~4000 m. Limb rotation forelimb recorded by geometry. Based bedrock strata, infer fold, conclude was formed simple-shear above ramp, backlimb down-lowering dip angle. Using previous age control for terraces, average rock uplift 1.2 ± 0.1 mm/a estimated range, produces total slip rate 1.8 ± 0.4 mm/a below Shan. This new indicates onset 2.5 ± 0.5 Ma Shan, suggesting this young range. result suggests outward accretion Plateau ~3 Ma, it provides insight into within recently deforming structures, process accommodating crustal shortening where thrusting