Velocity Structure of the Upper Crust and Its Geological Significance in the Jiaodong Area, China

Abstract

We determined the velocity structure of the upper crust in the Jiaodong area using double difference seismic tomography, and found that the Jiaodong inland area near the surface (0–5 km) is mainly characterized by high-velocity anomaly, and there are several obvious low-velocity anomalies in the Bohai Sea. The Queshan metamorphic core complex shows obvious low-velocity anomaly at the depth of 5–15 km, and the southern part of the Linglong shows low-velocity anomaly at the depth of 10–20 km. It indicates the existence of significant mantle material upwelling and magmatic activity beneath metamorphic core complex. The Linglong and Queshan metamorphic core complex may be still in the process of uplift. The high-velocity anomaly of the Wulian-Yantai fault is likely closely related to the basic to ultrabasic rocks from the mantle. The basic to ultrabasic rocks upwelling along the Wulian-Yantai fault zone is segmented and mainly concentrated in the southern of the fault zone.