Major factors of the evolution of basins and faults in the Baikal Rift Zone: Tectonophysical analysis

In order to identify the major factors of the formation of the Baikal Rift Zone, tectonophysical analysis is carried out based on physical modeling with the application of similarity criteria. A single-layer model of elastoplastic clayey paste is superposed on two metal plates. One of the metal plates is displaced leftward according to the simple shear mechanism and its contact with the second metal plate has a bend morphologically similar to the Baikal segment of a marginal suture of the Siberian Craton. This scheme of loading corresponds, to a great extent, to the passive mechanism of rifting; i.e., the deformed layer is destructed due to strikeslip displacement of blocks and development of pull-apart structure in the model without any uplift and thermal impact related to the influence of mantle asthenolith in nature. The series of runs reproduces the major spatiotemporal trends in the evolution of the Baikal Rift Zone. Some experiments achieve for the first time a high degree of similarity in the morphology and mutual alignment of its main basins. This makes it possible to conclude that the evolution of basins and faults in the Baikal Rift Zone was governed by the following factors: (1) elastoplastic response of the substrate with a regular localization of strain; (2) left-lateral displacement of blocks; and (3) the presence of curved (in plan view) initiating structural heterogeneity.