| Popis: |
Significant differences in the layered-block structure of the earth's crust and the upper mantle, expressed in the distribution of localized seismic inhomogeneities of the Aldan and Stanovoi blocks and the zone of their junction, are revealed. A laterally inhomogeneous near-surface two-layer structure with a velocity of 3.8-4.5 and 5.0-5.9 km/s at thicknesses of 0.3-1.0 and up to 2-4 km has been established, which overlaps the Early Precambrian basement of the shield with a velocity of 6.0-6.3 km/s. The crust in the Stanovoi block and the adjacent Central Aldan folded belt is represented by a two-layer, and in the Aldan block by a three-layer models. The zone of the Stanovoi Ridge separating them is characterized by exceptionally contrasting velocity inhomogeneities, which correlate with a step-like increase in the depth of the Moho from 40 to 50 km. |
