Seismic Evidence for Crustal Modification Across the Tanlu Fault Zone in Eastern China

Abstract

AbstractThe continental collision and subduction between the North China Craton and Yangtze Plate resulted in complex multistage tectonic episodes of the Tanlu fault zone. To adequately understand the geodynamic processes of the continental collision, we construct a high‐resolution shear‐wave velocity model of the crust and uppermost mantle using full‐wave ambient noise tomographic method based on a new broadband dense seismic array across the Tanlu fault zone. Our tomographic model reveals the uniquely alternating high‐velocity and low‐velocity anomalies from the lower crust to uppermost mantle across the Tanlu fault zone, which may result from the vertical slab tear of the subducted Yangtze Plate and the subsequent upwelling of hot asthenospheric materials. A prominent mid‐crustal detachment zone is observed along the Tanlu fault zone, which provides direct seismic evidence for the Tanlu fault zone that occurred strongly left‐lateral shearing deformation and may influence the uneven distribution of the strong earthquakes.