Shurabsay Fm

It was identified by N.P. Vasilyevsky (1952).

Synonym: Shurabsay suite, Shurabsai suite, Шурабсайская свита

Reference section:

The Shurabsay suite is best preserved in the Chorukhdayron graben and the Tashkessen and Adrasman basins. In the Yashkeresk basin, mainly subvolcanic facies of the suite are present.

In general, the section of the suite is four-membered:

1- arkosic conglomerates, gravelites, and sand Bedrock, containing pebbles of almost all older rocks of the Karamazar, the thickness ranges from several tens to 600 meters (Takeliy formation) (такелийская толща);

2 - dark gray, almost black, and green pyroxene trachyandesites and trachybasalts, as well as their agglomerates, thickness 200-800 meters (Uchochak, Pyazlysay, Dolonysay, and Suchilgan formations) (учоча1кская, пиязлысайская, долонысайская и сучилrанская толщи);

3 - brown and brick-red crystal tuffs and tuff lavas of trachytes, containing fragments of underlying trachyandesites, thickness 200-500m (Aynabulak and Chokadambulak formations) (айнабулакская и чокадамбулакская толщи);

4 - creamy and pinkish-gray fluidal and spheroidal lavas and ignimbrites of trachyphonolites at the base with a horizon (sometimes) of sandstones, tuff sandstones, and clay slates, thickness 200-600 meters (Sarytaipan, Tereklysay, and Karankul formations) (сарытайпанская, тереклисайская, каранкульская толщи).

The thickness of the Shurabsay suite (шурабсайской свиты) is 900-2000 meters.

In the Sarytaipanskaya and Tereklysayskaya formations (сарытайпанской и тереклисайской толщах), J.N. Kuznetsov in 1956 and B.I. Sigalov in 1962 collected remains of the flora Ullmania sp.; Cordaites angustifolius Neub., C. insignis Rades, C. (Noeggerathiopsis) theodori Tschet., Samaropsis eumarginata (Goepp. et Berg.) and others. According to T.A. Systel's conclusion, some of these forms are characteristic of the Lower Permian, while the rest are known both in the Upper Carboniferous and in the Upper Permian. Palynological studies in the Shurabsayskaya suite have established forms characteristic of the Kungurian: Cordaitina uralensis (Zub), Azonoletes ex gr. fabaginus (Sam.).