The velocity structure of the southern edge of the ancient Siberian craton has been modeled to an 80-km depth based on teleseismic records of a P-receiver function method (P–S). The correlation between the deep and the surface structure determined through modeling is indicative of the submeridional convergence of the south-western edge of the Siberian craton with the Central Asian mobile belt. A sublatitudinal crust extension in the contact zone caused by such convergence may initiate Baikal rifting at the craton’s southeastern edge.