Crustal architecture beneath the Tibet‐Ordos transition zone, NE Tibet, and the implications for plateau expansion

Abstract

Abstract Most previous studies of the Tibetan Plateau have focused on the processes of crustal thickening and subsequent outward growth. However, lithospheric structure across the tectonic boundaries of the plateau has not yet been fully imaged, and therefore, how geological structures evolved in association with the lateral expansion of the margins remains unclear. Here together with interpretation of regional aeromagnetic anomalies, we employ a recently acquired 165 km long deep seismic reflection image that crosses the northeastern flank of the Tibetan Plateau. The resulting crustal “architecture” suggests that crustal shortening is a primary driver for plateau uplift of northeastern Tibet and that the Xiaoguan Shan to the east of the Liupan Shan belt marks the easternmost edge of the strata that has been affected by the northeastward growth of the plateau. In addition, decoupled crustal deformation owing to differential structural integrity has been accommodated during the subsequent northeastward growth of the plateau.