The Central Asian Orogenic Belt (CAOB) was formed during the termination of the Paleo‐Asian Ocean in the Paleozoic. However, the mechanism and process of the Paleo‐Asian Ocean closure and CAOB formation remain controversial. This study presents a seismic image from the northern North China Craton to southern Mongolia derived from P and S receiver function analyses of the teleseismic records from a dense array. Our observations reveal a thicker lithosphere in the southern CAOB than in the Bohai Bay basin, which suggests that this Paleozoic orogen was less affected by the lithosphere reactivation in the eastern North China Craton during the Late Mesozoic. The imaged lithosphere‐asthenosphere boundary of the southern CAOB deepens southward and reaches a greatest depth of approximately 130 km beneath the Xilinhot fault, the northern boundary of the Solonker suture zone. The Moho displays a local uplift of approximately 5 km beneath the Linxi fault, the southern boundary of the Solonker suture zone. These features imply that the Solonker suture zone is the most plausible site of the lithosphere collision between the opposing continental margins. Additionally, a southward dipping intracrustal interface, whose depth extends from ~16 km beneath the Baolidao belt to ~20 km beneath the Linxi fault, is interpreted to be associated with the subduction of the Paleo‐Asian Oceanic slab. Additionally, the absence of lithosphere‐asthenosphere boundary phases beneath the Bainaimiao arc is inferred to be caused by the upwelling of hot mantle material after assembly of the CAOB.

Long‐standing debates exist over the mechanism of continental lithospheric extension and, more specifically, over the strain distribution across the lithosphere in intraplate settings. The Cretaceous extensional system in South China extends up to ∼800 km inboard of the Paleo‐Pacific convergent margin and enables investigation of the mechanism(s) of intraplate lithospheric extension. Here we use high‐resolution seismic reflection data to image the crustal and upper‐mantle architecture of the central segment of the extensional system. We identify a compositionally stratified upper lithosphere that has undergone depth‐dependent extension, expressed by heterogeneous normal faulting in the upper crust, widely distributed ductile stretching in the lower crust, mantle influx into the crust, a broadly smooth Moho with localized uplift, and mantle shear‐zone generation. We detect, beneath the center of the Ganzhou Rift, the thinnest crust (28–30 km thick) in South China. It spatially correlates with the locus of strong lithospheric thinning and asthenospheric upwelling. We suggest that the generation of the thinnest crust was assisted by lower‐crustal ductile stretching, mantle shearing, and exhumation during depth‐dependent extension. Our study provides insights into the partitioning of depth‐dependent extensional strain into an intraplate stratified lithosphere and the feedback between crustal and mantle processes that shaped the thinnest crust at a position ∼300 km inboard of the convergent margin during continental extension.