High‐Resolution Seismic Exploration of Xiuyan Impact Crater Structures

Abstract

The Xiuyan impact crater with a rim‐rim diameter of 1.8 km is located at northern hills in the Liaodong peninsula, Liaoning province, China, which is well reserved and confirmed by evidences from different sources to be a meteorite impact crater. A special geophysical field formed from the meteorite impact and subsequent deposit at the crater makes different medium velocity and density between inside and outside of the crater. In the project, velocity structures, stratum structures and whole configuration of the crater are gotten using the differences of seismic velocity and wave impedance from the combined exploration of reflection and refraction. Based on the reflection features of strata, the crater body formed by the direct impact has a diameter about 1.8 km and a depth about 800 m, and the depth affected by the impact is about 1.4 km. The crater structure is divided into 3 parts, slow deposition area, rapid deposition area and affected area. According to the seismic velocity features, the velocity at the crater center reaches 7.0 km/s at the depth of 800 m. The 7.0 km/s isoline is consistent with the crater configuration, but the velocity reaches 7.0 km/s at the depth of 500~600 m in the edge of the crater. The structure of the crater body and the physical property of rocks conform further that the Xiuyan crater is originated from meteorite impact.