Karatag Gr

It corresponds in volume to the Karatag suite of S.K. Ovchinnikov (Decisions.... 1959).

Synonym: Karatag series, Kаратаrская свитой

Reference section:

It is composed of greenstone diabase porphyrites, spilites, dacites, andesites, their tuffs and tuff-breccias with interlayers and lenses of limestones and claystones. The incomplete thickness of the series is 4000 m.

The foundation of the stratigraphy of the Karatag series was laid by the works of E.N. Goretskaya and P.G. Rysin, who in 1959 divided these deposits into four layers (from bottom to top): 1) lower albite-phylites; 2) spilite; 3) upper albite-phylites; 4) andesite. As a result of large-scale geological mapping works carried out in recent years by V.N. Yefimenko, E.A. Kostmynin, K.O. Tsooriev, D.A. Starshinin, V.N. Kuznetsov, etc., as well as thematic works by F.R. Bensh, new materials have been obtained that allow to refine and detail the scheme of E.N. Goretskaya and P.G. Rysin.

At the base of the section of the series (only at one point - Varzob River) there are albite-phylites and quartz porphyries, tuffs, tuffolava, and tuff-breccia of albite-phylites with interlayers of limestones, claystones, and sandstones ("lower albite-phylite layer" of E.N. Goretskaya and P.G. Rysin) with a total thickness of about 500 m. Above lies a powerful (from 1500 to 3200 m) layer of spilites, spilitic and diabase porphyrites, and their tuffs ("spilite layer" of E.N. Goretskaya and P.G. Rysin), containing small lenses and interlayers of limestones at the top of the section.

This layer constitutes the main volume in the section of the series; D.A. Starshinin proposes to name it hereafter the Sabirin suite. V.N. Yefimenko, E.A. Kostmynin, V.N. Kuznetsov, and K.O. Tsooriev, who have studied this layer in detail, note its three-membered structure, with a predominance of pyroclastic rocks at the bottom and top of the section and proper spilites in the middle part. In the top of the spilite layer, a peculiar horizon of pink. Depositions of ato-ash goniathite limestones with interlayers of claystones and volcano-mictic sandstones, thickness varying from 10 to 60 m, occur. In the basin of the р. Qaratag, the sequence lies on the limestones with apparent conformity, albeit a slight erosion at the base, and comprises a thickness (300 m) of frequently interbedded andesite tuffs, porphyrites, polymictic sandstones, clay-siliceous slates, and limestones (corresponding in age to the "Suffinskaya" suite according to D.A. Starshinin or the "northern zone of the distribution of the Suffinskaya suite" according to F.R. Bensh, 1969).

In the lenses of limestones in the upper part of the serpentinite sequence and in the horizon of pink limestones, capping this sequence, E.A. Khudobina, as well as V.N. Yefimenko, E.A. Kosmyinin, and Q.O. Tsoriev collected in the basin of the Qaratag river remains of Lower Namurian goniathites: Prolecanites sp., Rhiphaeccanites sp., Dimorphoceras cf. bisulcatum (Girty.), Trizonoceras typicale Girty., Tr. lepidum Girty., Cravenoceras aff. hesperium Miller et Furnish, Glaphyrites sp. Since the fauna is found at the very top of the serpentinite sequence, the age of its lower part may drop to the Viséan stage and even be even more ancient. In the interlayers of limestones of the overlying tuffaceous slate sequence, a numerous complex of Early Bashkirian age foraminifera is enclosed. The result is: Sta: Eostaffella pseudostruvei var. angusta Kir., E. varvariensis Prazhn. et Pot., Pseudostaffella antiqua (Dutk.), Ps. primitiva Reitl., etc. The andesite layer contains a late Bashkirian - early Moscovian foraminiferal complex: Ozawainella tingi (Lee.), Oz. angulata Col., Oz. umbonata Brazhn. et Pot., Oz. aurora Grozd. et Leb., Profusulinella ex gr. extensa Raus., Pr. aff. bona. Grozd. et Leb., Pr. cf. staffaeformis Kir. In the overlying Muborak suite, there is a late Moscovian brachiopod complex.

In other areas (valleys of the Ardzhanak, Khanaka, Qaratag rivers) on the serpentinite sequence (according to observations by E.N. Goretskaya, A.T. Tarasenko, E.A. Kosmyinin), lavas, tuff breccias, agglomerate lavas of dacites, liparites, albite-phires with interludes of tuffs and tuff breccias are observed ("upper albite-phire sequence" by E.N. Goretskaya and P.G. Rysin). Their thickness varies from 150 to 300 m. On the albite-phire sequence in the Khanaka river valley, a sequence is found, represented by monotonous lavas, tuff breccias, and less often, clastolavas of andesites, andesite and diabase porphyrites, up to 350 - 500 m thick ("andesite sequence" by E.N. Goretskaya and P.G. Rysin). In the Khanaka river incision to the south of Muborak, it lies on the albite-phire sequence with apparent conformity, and somewhat to the west (in the upper part of the Sayan Shamol), according to E.N. Goretskaya (1957) and observations in 1968 by E.A. Kosmyinin, there is a transgressive overlying of this sequence both on the albite-phire sequence and on the Khanaka intrusion of plagiogranites, where in the lower part of the section of the sequence there are fragments of plagiogranites, identical to those from the Khanaka intrusion. The last two sequences D.A. Starshinin combines into the Shamol suite. The andesite sequence is overlain by terrigenous rocks of the Muborak suite (шамольскую свиту) with erosion, but without apparent angular discordance.