The formation of Proval Bay as an episode in the development of the Baikal rift basin: A case study

This paper provides a cumulative review of important specific features in the formation and development of Proval Bay (Lake Baikal) as a large seismic dislocation element. This bay appeared during one of the largest historical earthquakes in Siberia (MLH 7.5) on January 12, 1862. As a result, more than 230 km2 of the shore was submerged. The paper considers the formation of Proval Bay in the context of analysis conducted on general morphological characteristics of the Baikal rift and in terms of the occurrence of the main elements in the mechanism of its neotectonic development. It is precisely these seismotectonic phenomena, associated with the subsidence of large tectonic blocks, which primarily cause the growth of Lake Baikal basin. In spite of the fact that the northwestern side of the rift has a more pronounced morphological structure, whose general elements are high and steep monolithic tectonic escarpments, major lithospheric extension and its associated extension of the rift, thinning and rearrangement of blocks in the upper lithosphere slab occur on the more gently sloping eastern side.