Microstructural and Seismic Characteristics of Mantle Xenoliths From Damaping Area, and Their Geodynamic Implications of North China Craton Destruction.

The large‐volume lithospheric mantle xenoliths around the Damaping area provides valuable insights into the detailed destruction progression of the North China Craton (NCC). This paper presents a quantitative analysis of the microstructural and seismic properties of oriented mantle xenoliths (with distinct foliation and lineation). The selected peridotites all have coarse‐grained textures. The olivine crystallographic preferred orientations (CPOs) are predominantly axial‐[010] type (or AG‐type), with all xenoliths have girdled [100]OL and [001]OL characteristics. B‐type olivine CPO is newly discovered in the research area. Analysis of crystallographic vorticity axis (CVA) projections indicates that more than half of Damaping xenoliths have CVA maxima (sub)parallel to the lineation. These microstructure characteristics suggest that B‐type CPOs were formed before the onset of pure shear‐dominated transpression and pyroxene restriction, which significantly influenced the lithospheric mantle evolution. The upwelling asthenosphere beneath Eastern Block of the NCC not only delaminated its lithospheric mantle but also experienced rollback and flowed along the WNW‐SEE direction. This progression likely serves as the primary driving force of transpression. If foliation were vertical and lineation were horizontal, the valid S‐wave anisotropies range is 5%–12%. All selected samples are spinel facies, resulting in a maximum in situ depth of 90 km, and the calculated SKS splitting delay times (0.5–1.3 s) align with previous seismological observations. The SKS direction in the research area is predominantly oriented perpendicular (NNE‐SSW) to the flow direction of nearby asthenosphere. These characteristics are likely attributed to transpression. Therefore, the "fossil" anisotropy may have developed after the cessation of transpression. Plain Language Summary: The mantle xenoliths extracted from the North China Craton (NCC) lithosphere record detailed geological information. This study focuses on the microstructural and seismic characteristics of the Damaping mantle xenoliths, all of which exhibit visible foliation and lineation. Our data reveal that the dominant olivine fabric has AG‐type characteristics, while a B‐type‐like olivine fabric has been newly discovered. These findings, coupled with crystallographic vorticity axis (CVA) data, suggest that the olivine B‐type fabric was generated earlier and was later replaced by the AG‐type fabric. Both pure shear‐based transpression and the overgrowth of pyroxene grains on olivine grains contribute to these characteristics. The driving force is believed to have originated from the destruction of the NCC lithosphere near the research area, where the upwelling asthenosphere rollback pinches the nearby lithosphere at the same depth. Olivine fabric‐based seismic calculations indicate that the in situ depth of the selected lithospheric mantle xenoliths is approximately 90 km, and the seismic properties suggest a stable status, implying that the nearby asthenosphere transpression was paused. This case study is instrumental in detailing the destruction progress of the NCC. Key Points: B‐type olivine CPO is newly discovered in mantle xenoliths and generated by diffusion creepMicrostructural evolution, primarily driven by pure shear‐based transpression, is attributed to the flowing asthenosphere along WNW‐SEEThe "fossil" anisotropy beneath the Damaping area might also be generated after transpression progress ceased [ABSTRACT FROM AUTHOR]