Upper crustal deformation in the xingmeng orogenic belt and adjacent areas: insights from active and passive seismic imaging

Determining the crustal velocity structure of the Xingmeng Orogenic Belt (XMOB) and adjacent areas is key to understanding its formation, evolution, and tectonic mechanisms. In this study, ambient noise imaging was used to process a SE–NW-oriented short-period dense array profile (length: 503 km) that crosses the Songliao and Erlian basins and the XMOB. We obtained an S-wave velocity structure and integrated it with active-source refraction tomography results from the same profile to study the geological structure of the upper crust. Imaging allowed for the detailed characterization of subsurface velocity features in the study area. By analyzing S- and P-wave velocity profiles, we identified low-velocity anomalies associated with fault and suture zones, along with their positions and distributions within the upper crust. The results show that different regions are influenced by major boundary faults, which also govern basin formation and sedimentation.