At the eastern Qilian Shan mountain front in the NE Tibetan Plateau, the Minle‐Damaying Fault (MDF), the southernmost fault of the North Frontal Thrust (NFT) system, has previously been proposed as an inactive structure during the Holocene. Here we present a detailed record of six strath terraces of the Xie River that document the history of active deformation of the MDF. One optically stimulated luminescence dating sample constrains abandonment of the highest terrace T6 at 12.7 ± 1.4 ka. The formation ages of the lower terraces (T4–T1) are dated by AMS 14C dating. The cumulative vertical offsets of the MDF recorded by these terraces are determined as 12.2 ± 0.4 m (T6), 8.0 ± 0.4 m (T5), 6.4 ± 0.4 m (T4), 4.6 ± 0.1 m (T3), and 3.2 ± 0.2 m (T1c) by an unmanned aerial vehicle system, respectively. A long‐term vertical slip rate of the MDF of 0.9 ± 0.2 mm/yr is then estimated from the above data of terrace age and vertical offset by a linear regression. Assuming that the fault dip of 35 ± 5° measured at the surface is representative for the depth‐averaged fault dip, horizontal shortening rates of 0.83–1.91 mm/yr are inferred for the MDF. Our new data show that the proximal fault (the MDF) of the NFT system at the eastern Qilian Shan mountain front has remained active when the deformation propagated basinward, a different scenario from that observed at both the western and central Qilian Shan mountain front.

Seismogenic faults are commonly composed of a series of segments, revealed by geometric barriers and along‐strike gradients in fault activity. At the northeastern margin of the Tibetan Plateau, the Minle‐Damaying Fault (MDF), bounding a portion of the eastern Qilian Shan, illustrates segmented paleoseismic behavior of a major seismogenic reverse fault. Field surveys, trench excavations, and drone‐surveyed topography along the MDF reveal scarps with diverse cumulative displacements. Multiple events, with timing constrained by radiocarbon dating, are identified by both trench exposures and analysis of deformed landforms. Both individual coseismic displacements and slip rates taper toward the ends, revealing repeated rupture of the western MDF segment. Not all events present at the center of this segment appear at sites closer to the fault tips, suggesting that some earthquakes did not everywhere rupture to the surface. Isolated rupture of the western segment would produce a Mw7.0 earthquake. However, we cannot rule out correlation of some paleo‐earthquakes between two segments, corresponding to larger events. A cluster of two 7‐m slip events occurred on the eastern segment in the past 1,000 years, one of which may correspond to a multisegment event.

The Qilian Shan, located in the northeastern Tibet, is under strong tectonic activity and earthquake motion due to the propagation of the plateau. At the mountain front of the eastern Qilian Shan, the Tongziba River, in the southern Zhangye Basin, flows northward and successively cuts the Minle-Damaying Fault and the Yonggu Anticline, two parallel structures within the Frontal Thrust system of the Qilian Shan. Here we present a detailed record of seven strath terraces of this river that documents the history of active deformation of the two structures. Based on the estimated crustal shortening distance from the deformed terraces and the terrace formation age constrained by AMS 14 C and optically stimulated luminescence (OSL) dating, a horizontal slip rate of 1.4 ± 0.5 mm/year of the Minle-Damaying Fault is constrained since 16.7 ± 1.8 kyr, and a shortening rate of 1.3 ± 0.4 mm/year across the Yonggu Anticline has been estimated in a similar time frame, respectively. In total, the shortening rate across the mountain front is estimated to be 2.7 ± 0.6 mm/year. GPS data show a similar modern shortening rate in this area, which indicates the rate of crustal shortening may be comparable in the modern and 10 4-year scales. Our study supports a higher crustal shortening rate along the mountain front of the eastern Qilian Shan than that of the western Qilian Shan since the Late Quaternary.