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

Abstract

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.

Insights Into Layering in the Cratonic Lithosphere Beneath Western Australia

“…There are now many observations of another discontinuity within the lithospheric mantle between these two boundaries that is often associated with a decrease in the shear wave speed. This midlithosphere discontinuity (MLD) is mostly observed at depths of 60–160 km (e.g., Aulbach et al, ) and predominantly at depths between 80 and 120 km (e.g., Selway et al, ; Sun & Kennett, ) beneath stable and old cratonic lithosphere around the world.…”

“…The topography of the MLD has been revealed through seismic receiver function analysis (e.g., Abt et al, ; Ford et al, ), underside reflections (e.g., Tharimena et al, ), and P wave reflectivities extracted from transmission responses (Kennett, ; Sun & Kennett, , and others). The MLD has been associated with both decreases and increases in the seismic velocity.…”

“…Here we explore the midlithospheric structure using a novel receiver‐based reflectivity approach that constructs high‐frequency, fine‐scale P wave reflectivities from transmitted waves, including multiples between the free surface and discontinuities beneath seismic stations (Sun & Kennett, , ). Other geophysical information, including tomographic P and S wave velocity, radial anisotropy, electrical resistivity, and thermal data, are then used to demonstrate the possible mechanisms of the MLD beneath the Western Australian Craton.…”

Detection of seismic events on Mars: a lunar perspective

“…Heat flow from interior to surface is another useful geophysical measurement that would provide direct information of deep mantle tectonic activity. Cratons are considered to be the oldest and the most stable tectonic units on Earth, with heat flow values as low as 40 mW/m 2 or lower, e.g., the West Australian Craton (Sun WJ et al, ), but also twice or triple that value, reaching ~100 mW/m 2 , for example, in the destructed North China Craton (e.g., Sun WJ and Kennett, ).…”

Crustal Imaging With Bayesian Inversion of Teleseismic P Wave Coda Autocorrelation

“…Despite the success of many studies on the processing and/or forward modeling of autocorrelograms (e.g., Becker & Knapmeyer‐Endrun, ; Clayton, ; Daneshvar et al, ; Gorbatov et al, ; Heath et al, ; Ito & Shiomi, ; Kennett et al, ; Kennett & Sippl, ; Nishitsuji et al, ; Oren & Nowack, ; Phạm & Tkalčić, , ; Phạm et al, ; Romero & Schimmel, ; Ruigrok & Wapenaar, ; Saygin et al, ; Sun & Kennett, , ; Sun et al, ; Taylor et al, ; Tibuleac & von Seggern, ), to our best knowledge, there are no published studies on the inversion of autocorrelograms for mapping major discontinuities in the crust and upper mantle. Here, we investigate the inversion of autocorrelograms for crustal imaging.…”