Complex sentence: From springs in Gobi flow along Yenisei then dammed by northern glaciers trough West Siberian Glacial Lake flowed about 10000 km; Mangerud, J. et al.
Split into simpler sentences: From springs in Gobi it flowed along the Yenisei, which was then dammed by northern glaciers. Through the West Siberian Glacial Lake flowed about 10,000 km; Mangerud, J. et al.