Coupled Lithospheric Deformation in the Qinling Orogen, Central China: Insights From Seismic Reflection and Surface‐Wave Tomography
Yueqiao Zhang, Shuwen Dong, Haiyan Wang, Mei Feng, Hans Thybo, Jianhua Li, Rui Gao, Wei Shi
Abstract
Abstract We combine a ∼485 km‐long seismic reflection profile and a S‐wave speed transect from surface‐wave tomography, to reveal the lithospheric deformation mode of the intracontinental Qinling orogeny, central China. We observe a thick lithosphere keel in the convergence zone between the Yangtze Block and the North China Craton (NCC) and a shallow‐crustal (8–15 km depth) décollement that extends into the lower crust of the Qinling Orogen. Combining with surface structural geology and magmatism, we interpret these seismic findings as kinematically linked features formed by renewed intracontinental convergence between the NCC and the Yangtze Block in the late Mesozoic. We highlight that the ∼40 km lithospheric thickening in the convergence zone was likely balanced by > 130 km thin‐skinned crustal shortening along a crustal‐scale strain‐transfer décollement, and was responsible for the occurrence of late Mesozoic magmatism (∼160–100 Ma) at the southern edge of the NCC.