Nature of the intermediate seismic zone in the mantle of Pamirs—Hindu-Kush

The principal seismicity of the Pamirs—Hindu-Kush area is closely related to a high-velocity body in the region. The dimensions of this body, and its relation with the outcrop of a large area of Precambrian shield-like terrain suggest that it may be the rigid downward extension of a piece of old shield, and that the concentration of stress around its eastern extremity is the source of the anomalous intermediate seismic activity of the region.