Crustal thickness and Vp/Vs ratio of the central and western North China Craton and its tectonic implications

Abstract

We obtained the crustal thickness (H) and average Vp/Vs ratio (κ) for the central (CNCC) and western North China Craton (WNCC) by H–κ stacking of receiver functions. Our results show that H and κ varies significantly but similarly in the northern and southern CNCC, reflecting possible effects of the Phanerozoic cratonotic reactivation on the region. Of the WNCC, the south is featured by κ values typical for Precambrian shields (∼1.77) and variations of H mirroring surface topography; the north presents large fluctuations of κ (1.68–1.93) and a crustal thickening (up to 50 km) uncorrelated with topography. Such N–S differences were thought to be associated with a ∼1.95-Ga suturing event occurred in the north with little effects on the south. Our observations suggest that distinct structural heterogeneities of the NCC not only reflect diverse regional tectonics in Phanerozoic, but also provide evidence for long-term survival of crustal fabrics in stable continental interior.