Objective The Beishan occupies a pivotal position between the eastern and western segments of the Central Asian Orogenic Belt (CAOB). Although numerous ductile shear zones have been identified in this area, they have received limited attention, leading to uncertainties and debates regarding their formation mechanisms, ages, deformation regimes, tectonic settings, and role in the evolution of the orogenic belt. Consequently, studying these ductile shear zones is crucial for understanding the evolution of the CAOB.

Methods Based on a systematic compilation of previous research data, the geological interpretation of remote sensing images, the regional aeromagnetic anomalies of the East Tianshan–Beishan–Alxa region, and our fieldwork in Beishan and adjacent regions, this study has identified 13 ductile shear zones, ranging in length from 30 km to nearly 300 km.

Results These 13 ductile shear zones from north to south are: Hongshishan–Baiheshan–Pengboshan–Qiantiaogou ductile shear zone, Bailiang–Sangejing–Gonglujing–Weiboshan ductile shear zone, Pochengshan–Shibanjing–Xiaohuangshan ductile shear zone, Hongyanjing–Mazongshan–Jianshan ductile shear zone, Lebaquan ductile shear zone, Baiyunshan–North Yueyashan ductile shear zone, Huaniushan–Wufengshan–Erduanjing–North Dingxin ductile shear zone, Zhongqiujing–Jinmiaogou ductile shear zone, Jiujing–Chuanshanxun ductile shear zone, Xiaoxigong–Qianhongquan ductile shear zone, Qijiaojing shear zone, Gubaoquan–Zuanjinggou ductile zone, Baidunzi–Shibandun ductile shear zone, respectively. Most of these 13 shear zones exhibit an east–west strike, traverse the entire Beishan region, and coincide with ophiolitic mélange zones or major tectonic zones. Those in the southern Beishan region are particularly well-exposed, characterized by greater widths (>10 km) and a higher concentration (five to six zones), whereas those in the central and northern regions display greater continuity and length. Currently, most documented shear zones in Beishan are dominated by dextral kinematics, with only a few exhibiting sinistral motion. Mineral stretching lineations in major shear zones are generally sub-horizontal and east–west trending, while mylonitic foliations generally strike east–west with steep to vertical dips. Preliminary findings suggest that most ductile shear zones in Beishan formed during the Paleozoic and Mesozoic, particularly in the late Paleozoic to early Mesozoic, with a predominant distribution in the central and southern regions. Many of these major shear zones can be correlated with coeval structures in the East Tianshan to the west and the Alxa region to the east, collectively forming an extensive ductile shear system in the central CAOB.

Conclusion These late Paleozoic to early Mesozoic shear zones likely reflect large-scale deformation within the CAOB and may represent a key component of the central megashear system in the Pangea supercontinent. However, the possibility that the ductile shear deformation in the Beishan region was caused by oblique subduction of the Paleo-Asian Ocean cannot be ruled out. Future research on Beishan’s ductile shear zones should prioritize precise geochronology and semi-quantitative to quantitative structural analyses. Significance The identification of the orogen-scale giant ductile shear system in Beishan and its vicinity is of great significance for understanding the deformation styles, environments, and regimes of the middle-lower crust in the CAOB, as well as the formation and evolution of the Pangea supercontinent.