Zyryuzamin Fm
Type Locality and Naming
Delineated by A. Kh. Kafarsky and I. V. Pyzyanov (1963), but its volume has been changed in accordance with new data (Luchnikov, Polyansky, 1974).
Synonym: Zyryuzaminskaya suite (3юрюзаминская свита)
Reference section:
Lithology and Thickness
It is represented by a powerful sedimentary-volcanogenic series of variegated - purple, gray, green rocks.
The Zyryuzamin Fm (Зюрюзаминская свита) is composed of andesites, andesite-basalts, basalts, porphyrites, tuffs, tuff-sandstones, tuff-conglomerates, containing layers of siltstones, sandstones, gravelites, carbonaceous rocks, and coal seams. The thickness of the suite is 1200-2000 m.
Relationships and Distribution
Lower contact
lying conformably on the formations of the Kyzylsui Fm. The relationship between these suites is not entirely clear. According to V. S. Luchnikov, this is the same series of rocks of Middle, Upper Triassic age. The Zyryuzamin Fm is a direct continuation of the upper part of the sedimentary-volcanogenic series. Previously (Kafarsky, Pyzyanov, 1963; Polyansky, 1973) to this suite, they referred to all or part of the Jurassic coal-bearing thickness of the Lower, Middle Jurassic age. At the same time, a powerful (up to 18 m) kaolinite-oxidized iron weathering crust, capping the effusion, was not noticed.
Upper contact
The upper boundary of the Zyryuzaminsk suite is traced by us along the weathering crust.
Regional extent
It is widespread in the Zaalaysky and Darvaz districts. The most complete sections are known in the upper reaches of the Zyryuzaminsk River and along the left bank of the Khingou River, in the interfluve of the Iochnakdara - Mionadu. In the latter area, between two volcanogenic layers, 700 and 900 m thick, lies an effusive-sedimentary layer up to 550 m thick with a whole series of powerful coal seams.
GeoJSON
Fossils
In this Iochnakdara - Mionadu layer, B. V. Poliansky (1973) identified poorly preserved plant imprints Equisetum (?)., Cladophlebis sp., Phoenicopsis sp., Yuceites (?) sp. According to T. A. Sikshtel, this flora has a Triassic appearance.
The author has identified and determined from this layer numerous plant remains: Equisetum arenaceus (Jacger) Schenk, Neocalamites carrerei (Zeill.) Halle, N. hoèrensis (Schimp.) Halle, Schizoneura sp., Danaeopsis sp., Podozamites lanceolatus (Lindl. et Hutt.) Braun, P. distans (Presl) C. Braun, P. schenkii Heer, P. latissimus Stanisl. For the indicated plant complex, it is characteristic to have a large number of various horsetails (up to 70% of all imprints), usually large. Among the horsetails, representatives of Neocalamites predominate. Representatives of the genus Equisetum are rare. Schisoneura and Danaeopsis are singular and fragmentary.
Age
Depositional setting
Additional Information