Varying Shear Wave Splitting Parameters Suggest Interaction Between Lithosphere and Asthenosphere in Arxan‐Chaihe Volcanic Field, NE China

Abstract

Over 2 years of broadband seismic data from 27 temporary stations deployed in the Arxan-Chaihe Volcanic Field (ACVF) provides us a valued opportunity to study mantle deformation and related geodynamic processes in NE China intraplate region. We estimated 153 pairs of high-quality teleseismic shear wave splitting parameters at 22 stations and 98 non-splitting measurements at 19 stations. Most of the stations in ACVF are characterized by NNW–SSE trending fast directions with variable splitting delay times, suggesting the fossilized extensional deformation within the lithosphere is locally thermal erased by the hot mantle upwellings associated with the volcanism. In the region south of the 46.5°N, a sharp swing of fast polarization occurs, and both nearly NW-SE and W-E oriented fast directions are observed, which could be explained by small local mantle convection caused by the lithospheric delamination.