Kyzylkuren Fm
Type Locality and Naming
The Kyzylkurensky suite was distinguished by N. P. Vasilyevsky (1952).
Synonym: Kyzylkurensky suite, Кызылнуринская Свита
Reference section:
Lithology and Thickness
The younger Samgarsky layer, composed of massive brick-red trachyliparites, distinguished here, is, according to V. N. Baykov, V. V. Mikhailov and V. A. Moskvichev, an extrusive formation. In this depression, the Kyzylkurensky suite fills the ancient caldera 20 km long and 6 km wide.
In the Tashkessen depression (Таш.кескенской мульде), the Tashkessen layer relates to the Kyzylkurensky suite. It begins with trachyliparite tuffs, followed by tuff sandstones and tuff conglomerates, and finally spherolithic trachyliparites.
In the Lashkeretsky depression (Лашкерекской мульде), in its northeast part, the considered suite is made up of pink and reddish-gray spherolithic and fluidal trachyliparites, their clastolava and tuffs. In places, there are tuff sandstones, sandstones and conglomerates at their base. The incomplete power of the suite is 800 m.
In Eastern Karamazar, a Babaysitenskaya "thickness" was distinguished (Vasilkovsky, 1952), composed of dark brown fluidal trachyliparites. According to V. N. Baikov, V. V. Mikhailov and V. A. Moskvichev, these rocks are found only in subeffusive facies, forming craters, necks, and ring dikes. They intrude the volcanics of the Upper Carboniferous Oyasayskaya and Lower Permian Shurabsayskaya suites, as well as comagmatic with the Shurabsayskaya suite, quartz syenites of the Permian Chorukhdaironsky complex, and have the same chemical composition as the blanket facies of the Kyzyl-Nurinsky suite. Based on the presented facts, these fluidal trachyliparites are considered by V. N. Baikov, V. V. Mikhailov, and V. A. Moskvichev as subeffusive formations of the Kyzyl-Nurinsky suite.
Relationships and Distribution
Lower contact
The Kyzylkuren Fm (Кызылнуринская свита) lies with erosion on all more ancient formations, including the Ravash Fm. It is the youngest in the section of Carboniferous-Triassic volcanics of Karamazar.
Upper contact
Regional extent
It is widespread in the Karamazar region in the Lashkeretsky and Tashkessen depression, where its sections are somewhat different.
GeoJSON
Fossils
Beyond the region, in the left bank of the Bashkizylsay (Chatkal ridge) in the Kyzylkurensky suite, T. A. Siktstel (1960) found the remains of plants, of which Pseudovoltzia liebeana Gein. is known from the Lower Triassic of Fergana, and Williamsonia artemovae sp.n. is similar to Late Triassic and Jurassic representatives of this species. According to the data of M. S. Babakhodzhaev, G. T. Tajibaev and V. N. Baykov, obtained by 1968, radiological studies of the rocks of the Kyzylkurensky suite in the territory of Tajikistan gave figures of 212-269 million years, which corresponds to the Middle Triassic - Early Permian epochs, and the age of the intruding granites is 172 - 204 million years, which corresponds to the Early Jurassic and Late Triassic epochs.
Age
Depositional setting
Additional Information
Different conclusions were obtained by N. P. Laverov and I. B. Ivanov (Geochronology of the USSR, vol. 2, 1974) during systematic investigations of the age of magmatic rocks of the Chatkalo-Kuraminsky zone, including the Karamazar district, using the argon method. According to the obtained results, the radiological age of the rocks of the Kyzyl-Nurinsky suite, including those that lie on the aforementioned layers with flora by Bashkyzylsay, is equal to 260 - 280 million years, which corresponds to the Early Permian epoch. N. P. Laverov and I. B. Ivanov believe that magmatic formations younger than the Lower Permian in the Karamazar district are absent.