Features of the Deep Velocity Structure of the Trans-Baikal Section of the Central Asian Folded Belt From Seismology and GPS Data (In the Alignment of the Reference Profile 1-Sb)

Abstract

The materials of deep seismic studies on the reference geophysical profile 1-SB and areal interpretation of seismological data in the Trans-Baikal part of the Central Asian folded belt are presented. It is shown that longitudinal and transverse waves from the reference boundaries in the Earth's crust and Moho surface were registered using explosions and powerful vibration sources on the 1200-km geophysical profile 1-SB in Trans-Baikal region. The inhomogeneous velocity structure (according to P - and S - waves) of the upper part of the Earth's crust to the depths of 15–20 km and Moho surface was established. The anomalous mantle with reduced values of the boundary velocity of P - and S-waves (7.8–7.95 km/s and 4.3–4.5 km/s, respectively) was reliably traced within the Baikal rift zone using GSS and seismology data. In the southeastern part of the area (in the central Mongol-Okhotsk orogenic belt and adjacent folded structures of the Trans-Baikal region), a layer of increased P-and S-wave velocity values on was detected the mantle surface at 8.4 ± 0.15 km/s and 4.9 ± 0.05 km/s, respectively. A comparison was made with the materials of other studies.