Uya Fm

Along the Uya River, Karzhantau Ridge. N.P. Vasilkovsky in 1939-1941 (131, p. 35). Stratotype in the upper reaches of the Uya River, left tributary of the Kelif River.

Synonym: Uya Formation, Уя св.

Lower part of the suite (mountain "a" of N.P. Vasilkovsky) - greenish-gray tuffaceous sandstones with horizons of volcanomictic conglomerates. Clasts in the conglomerates are of varying sizes, well-rounded, and consist of limestones, marbles, cherts, effusive rocks, and, rarely, intrusive rocks. Among the tuffaceous sandstones, rare and thin layers of sandy organogenic limestones with Serpukhovian fauna are found. Thickness is about 400m. Middle part (mountain "b" of N.P. Vasilkovsky) - tuffaceous sandstones, carbonate sandstones with subordinate layers of tuffoconglomerates, interbedded with limestone layers (thickness from 5 to 20m), which serve as good marker beds. Thickness is 200-250m. Upper part of the suite (mountains "v", "g", "d" of N.P. Vasilkovsky) in the stratotype - tuffaceous sandstones, sandstones, tuffs, tuffoconglomerates, trachytes, rarely trachybasalts.

Laterally, to the east of the stratotype, within 4-5 km, a facies transition of the terrigenous-volcanogenic deposits of the upper part of the Uya suite to the volcanogenic-effusive formations of the Minbulak Fm (473) is observed. Total thickness of the suite is about 800-1000m.