Seismic velocity structure and composition of the continental crust: a global view

Abstract

Seismic techniques provide the highest-resolution measurements of the structure of the crust and have been conducted on a worldwide basis. The paper summarizes the structure of the continental crust based on the results of seismic refraction profiles and infers crustal composition as a function of depth by comparing these results with high-pressure laboratory measurements of seismic velocity for a wide range of rocks that are commonly found in the crust. The thickness and velocity structure of the crust are well correlated with tectonic province, with extended crust showing an average thickness of 30.5 km and orogens an average of 46.3 km. Shields and platforms have an average crustal thickness nearly equal to the global average. -from Authors