Mid‐lithosphere discontinuities beneath the western and central North China Craton

• Published in: Geophysical research letters 2017-02, Vol.44 (3), p.1302-1310
• Main Authors: Sun, Weijia, Kennett, B. L. N.
• Format: Article
• Language: English
• Subjects: autocorrelogram; Cratons; Daylight; Discontinuity; Geophysics; Heat flow; Heat transmission; Heterogeneity; Imaging; Isotopes; Light; Lithosphere; Magma; midlithosphere discontinuity; North China Craton; P reflectivity; Rayleigh waves; Seismic activity; Seismic analysis; Seismology; Velocity
• ISSN: 0094-8276; 1944-8007
• DOI: 10.1002/2016GL071840

By analyzing P reflectivity extracted from stacked autocorrelograms for teleseismic events on a dense seismic profile, we obtain a detailed image of the mid‐lithosphere discontinuity (MLD) beneath western and central North China Craton (NCC). This seismic daylight imaging exploits a broad high‐frequency band (0.5–4 Hz) to reveal the fine‐scale component of multi‐scale lithospheric heterogeneity. The depth of the MLD beneath the western and central parts of the NCC ranges 80–120 km, with a good match to the transition to negative S velocity gradient with depth from Rayleigh wave tomography. The MLD inferred from seismic daylight imaging also has good correspondence with the transition from conductive to convective regimes estimated from heat flow data indicating likely thermal control within the seismological lithosphere. Key Points The mid‐lithospheric discontinuity beneath the western and central North China Craton occurs between 80 and 120 km depth Stacked teleseismic autocorrelograms reveal fine‐scale lithospheric structure with high‐frequency seismic waves The mid‐lithosphere discontinuity agrees well with the base of the thermal lithosphere