Khanakin Fm
Type Locality and Naming
Includes in Dushanbe-west Shirkent-Luchob, east Shirkent-Luchob. It was distinguished by M. S. Shvetsov (1927).
Synonym: Khanakinskaya suite, Ханакинская свита, Khanakinsky suite, ханакинской свиты, Hanakinsky suite
Reference section:
Lithology and Thickness
The suite is composed of red (reddish-brown and purple) conglomerates, gravelites, sandstones, siltstones, and clays containing layers and lenses of dacites, porphyrites, and their tuffs. Thickness 800-2500 m. The composition, structure, and thickness of the Hanakinsky suite are described based on data from the author who studied this section in recent years.
The section of the Khanakin Fm (ханакинской свиты) is clearly subdivided into three heterogeneous series of rocks. The lower series of rocks, up to 530 m thick, consists at the base of beds and lenses of volcanics with a basal conglomerate horizon (from 1.2 to 15 m). The volcanic formations - tuffolava, tuffs, tuffites - are represented by moderately acidic rocks of the normal calc-alkaline series, close to dacites. Their thickness is 20-120 m. They are overlain by a mass of brown clays and gray-colored heterogeneous sandstones, which in the upper part of the section are replaced by gravels and conglomerates. Volcanics are present in the lower half of the mass. The middle series of rocks, over 1500 m thick, is composed of purple-gray and gray lenticularly interbedded conglomerates, breccias, gravels, and heterogeneous sandstones. The upper series of rocks, up to 350 m thick, is composed of alternations of fine-grained sandstones and claystones of brown-gray and gray color.
Relationships and Distribution
Lower contact
The Khanakinskaya Fm lies with erosion and a slight angular unconformity on the Lower Permian Ducharob Fm (дучобской свите), as well as - with a sharp angular unconformity - on more ancient rocks.
Upper contact
The Khanakin Fm (ханакинской свиты) is overlapped with erosion and a sharp angular unconformity by coal-bearing formations of the Lower-Middle Jurassic, often with a weathering rind at the base. It lies with a sharp angular unconformity with Tashkutan Fm.
Regional extent
It is widespread in the Dushanbe district.
GeoJSON
Fossils
According to T. A. Sixtel (1960), in the lower part of the section compiled by her, plant remains of Hissarella schamalensis Sixt., UlImannia bronii Goepp., Bardella splendida Zal., Walchia cf. filiciformis Schloth., Lecrosia florinii Sixt. were found, "on the basis of which the age of the section is considered late Permian" (Geol. USSR, vol. 23, 1972, book 1, p. 353).
In the upper part of the section, remains of lower Triassic plants Pseudovoltzia liebeana (Gein.), Albertia sp., Hissarella schamolensis Sixt., Sphenopteridium brickianae Sixt., Yuccites shensiensis Sze, Stachyotaxus sp., Ulmannia bronni Goepp. and others were found (Siktell, 1900; Geol. USSR, vol. 23, 1972, book 1, p. 369).
Age
Depositional setting
Additional Information