Assake-Audan

(also Assake-Kaudan), a depression in the southern part of the Ustiurt Plateau in Kara-Kalpak ASSR and Kazakh SSR. The length of the entire depression is greater than 150 km; its width is 85 km. Situated at an elevation of less than 100 m above sea level, it was flooded by a salty Pliocene (Apsheron) lake. Its internal portion (length 90 km, width 35 km) falls below 50 m (minimum 29 m) and in the Late Quaternary Period was part of the Sarykamysh freshwater lake, which was fed by the waters of the Amu Darya River. The sides and bottom are composed of carbonate clay, marl, and Sarmatian limestone covering the gypsifer-ous Middle Miocene. Argillaceous-detritus, argillaceous, and partly solonchak deserts are characteristic landscapes.