Structure of the mantle transition zone beneath the central and western North China Craton and its adjacent areas revealed by P wave receiver functions

We obtained a total of 174 562 high quality P wave receiver functions by processing the teleseismic waveform data recorded by 823 temporary seismic stations of ChinArray phase Ⅱ and Ⅲ deployments, and then used the receiver function common conversion point （CCP）stacking method to study the structure of the mantle transition zone beneath the central and western North China Craton and its adjacent areas. The estimated thickness of the mantle transition zone in this studied area varies from 235 km to 280 km and shows partitioned characteristics. The thick mantle transition zones beneath the eastern Altyn Tagh fault belt and the northern Hannuoba volcano may be related to the detachment of the cold lithosphere. The mantle transition zones beneath the Hetao basin and the Yinshan orogenic belt are thinner than the average of the global mantle transition zone, which maybe imply the upwelling of the hot mantle materials or magma activities. The anomaly of the thicker mantle transition zone beneath the Bohai Bay basin may be caused by the westward subduction of the cold Pacific plate and its remaining in the mantle transition zone.