3D Lithospheric Structure in Southwestern Qin-Hang Metallogenic Belt — A Result from Broadband Seismological Observations

Abstract:

Southwestern Qin-Hang metallogenic belt faces almost all important geological focuses, such as the collision boundary between Yangtze Block and Cathaysia Block, the tectonic evolution with its controlling function to rock and ore etc. However, these controversial problems are still in debating strongly due to its complicated tectonics and sparse stratum outcrops, especially lack of information from deeper structures.

In Southwestern Qin-Hang metallogenic belt and its adjacent Region, we are arranging a 42 portable seismic array with an aperture of about 0.5°×0.5° to establish the 3D lithospheric P-wave velocity structure and try to better understand the relationships between deeper structure and the metallogenics in Southwestern Qin-Hang metallogenic belt, especially to determine the boundary between Yangtze Block and Cathaysia Block in this region.

Based upon the seismic data from almost two and half years broadband seismological observations, the result from the 3D lithospheric tomograpghy shows a rough tectonic framework which will provide deeper information about the lithospheric structure for better understanding the tectonic evolution of the southeastern China block. The observation is still gonging on with a more dense stations (the aperture to be about 0.3°×0.3°) , and the model will be refined and improved by using more seismological data.