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How did Lake Baikal form within the Baikal Rift Valley?

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Snow-capped, rugged Atlas Mountains encircle a green valley with scattered trees, terraced fields, and a few small buildings in Morocco. — valley The rugged Atlas Mountains surround a valley in Morocco.

Lake Baikal formed within the Baikal Rift Valley as a result of tectonic processes involving the Earth's crust. Unlike some rift valleys that form over large domes, the Baikal Rift is associated with distant forces, specifically those related to the collision of India into Eurasia.1

The formation of the lake is tied to the development of a rift valley, which is an elongated trough created by the subsidence of a crustal segment between normal faults. In this process, blocks of rock move downward relative to adjacent blocks, creating a deep structural hollow.234

The resulting basin is asymmetrical, characterized by a very steep northwestern edge and a gentler southeastern margin. This structure is formed by a combination of major faulting and the tilting of the lithosphere. Over millions of years, this deep, subsiding depression has collected water to become the world's deepest and oldest freshwater lake.14