Materials on the Stratigraphy of the Lower Balakhon Subseries of the Anzher District of Kuzbass

O. K. SKRIPKO

(Presented by the scientific seminar of the Department of Fossil Fuels)

The local subdivision of the Lower Balakhon subseries into the Chelyan and Central units in the Anzher district of Kuzbass was established according to the principle of coal-bearing character in the practice of geological exploration work. The lower boundary of the Chelyan unit is drawn along the floor of the Nizhnii seam; its upper boundary is the floor of the Koksovyi seam. The upper boundary of the Central unit is along the roof of the Naddesyatyi seam (or 15–20 m above the Desyatyi seam) (Fig. 1).

Several attempts are known to correlate the indicated units, including the Alchedat unit, with the Kemerovo stratotype.

The first, most general correlation on a paleobotanical basis was carried out by A. D. Zalesskii [2], and later by G. P. Radchenko [6].

The correlation by N. M. Belyanina and Z. D. Zavistovskaya [1], confirming P. G. Gryazev’s supposition, was based mainly on lithology and general geological considerations.

A. Z. Yuzvitskii [8] somewhat shifted the boundaries of the previous correlation, including in the volume of the Alykaevskaya subformation of the Anzher deposit the entire section from the Nadkonglomeratovyi seam to the roof of the Alchedat III seam.

It follows from this that the boundaries of the above-mentioned correlations are not stable. With the exception of the last work, all of them are based on scattered, few collections of paleontological material and use individual conclusions based on old specimens not precisely tied to the section.

Several references to the Anzher district in the description of individual species, for the purpose of substantiating the general correlation [5, 6], are not precise. Maximum attention in this respect was paid to the Kemerovo stratotype; the mechanical transfer of paleobotanical complexes to the Anzher section is also not excluded. Large systematic collections in the Anzher district had not been made until recently. The known lists of species in the works of previous authors substantiate membership in the volume of the Lower Balakhon subseries without correlation boundaries.

In the last work [8], the parallelization is supported by a large list of pelecypod fauna and flora (identified by P. A. Tokareva and G. S. Gorelova), tied to horizons provisionally distinguished according to lithological principles for the convenience of the paleotectonic analysis carried out by A. Z. Yuzvitskii. The proposed complexes of fauna and flora are usual for the Lower Balakhon subseries and include associations closely connected in the vertical section, without separate guide species for a narrow interval of the section [7, 8].

In the present article certain regularities are set forth in the distribution of fossil flora in the section of the Anzher deposit, obtained as a result of collections over the course of the last several years.

From numerous boreholes and mine workings of the Anzherskaya, Sudzhenskaya, and “Fizkulturnik” mines, a special complex of impressions of cordaitalean leaves has been found in the upper part of the Chelin Formation. It should be noted that the specific determination of the leaves is sometimes made difficult by the high coalification of the phytoleims and requires additional collections and further study. The assignment to the genera Cordaites Unger or Rufloria Meyen, however, is in most cases quite definite. Among these leaves, ruflorias are observed here resembling R. Theodorii (Tschirk. et Zal.) Meyen, but with fine dorsal grooves. In old determinations these leaves may have been identified with the typical Alykaevian R. Theodorii as part of the collective genus Noeggerathiopsis. Their impressions have been encountered in the floor of the Chelinsky II seam and possibly higher in the section up to the Koksovyi seam. Together with them, large long specimens have been encountered, likewise belonging to the genus Rufloria, with a weak divergence of veins, whose frequency resembles that in the description of Noeggerathiopsis tyrganica Radcz, from the upper horizons of the Tom-Usa district [5].

Here as well (the interval of the Chelinsky seams) leaves have been found with veins of sharply varying thickness, possibly belonging to the genus Zamiopteris Schmalh.

Fig. 1. Extent of the Alykaevo Formation in the Anzher district according to the views of different authors

Visible labels in the figure: “Stratigraphic column”; “Seams”; “Aprelskaya Formation”; “Ishurapinskaya Formation”; “Chelinskaya Formation”; “Volman Formation, Sobolev and Davydov, Kuzbass horizons”; authors: “Z. D. Zabeina, explanatory note to the 1958 map”; “R. Z. Yuzvitskii, 1970”; “O. K. Krinko, 1972”; legend: coal, argillite, aleurolite, sandstone. Seam names visible include: Antedatskie; Odinnadtsatyi; Naddesyatyi; Desyatyi; Andreevskii; Dvoinoi; Petrovskii; Larkin; Sych; Koksovyi; Chelinsk I; Chelinsk II; Chelinsk III; Chelinsk IV; Podvolgotom.

Impressions of R. Theodorii in this part of the section are not numerous; in relation to the remaining species they constitute no more than one quarter of their number. This ratio is maintained, according to our observations, up to the Koksovyi seam, in the floor of which R. Theodorii begins to predominate sharply over the area of the entire deposit, being one of the principal coal-formers within the whole flora of the deposit (from the northernmost exploratory lines to the field of the “Fizkulturnik” mine).

Angarodendron Obrutschevii Zal., often mentioned in lists of Alykaevo forms, according to our observations was not encountered above the Koksovyi seam at the Anzher deposit, except in those cases,

when the Chelin beds were brought to a shallow depth as a result of tectonic movements.

Paragondwanidium sibirisum (Pet.) S. Meyen is widely distributed in the section of the Koksovy Seam and above. It is interesting that, within the Chelin unit, this species is so far known only near the Konglomeratovy Seam (a single find).

As is known, there is as yet no clear demarcation of the Mazurovo complex from the Alykaevo complex, which is explained by the insufficient study of the Kemerovo stratotype nearest to the Anzher district. The distribution of individual species indicated above may be regarded as a local paleogeographic factor. It may serve as a paleobotanical basis for the local (district) separation of the two units of the Anzher deposit, and will prove all the more convenient because such a boundary represents a natural limit in coal accumulation in the north of Kuzbass. The flora complex of the upper Chelin unit appears so different from that of the overlying packet of converged Dvoinoy–Koksovy seams that it may be more correct to consider it as part of the Mazurovo complex and thus to draw the boundary between the Mazurovo and Alykaevo formations in the Anzher district at the floor of the Koksovy Seam.

A final assessment of the stratigraphic significance of this complex will be confirmed after materials are obtained from these horizons of the Kemerovo and other districts and processed at the present-day level.

Impressions of Rufloria Theodorii, R. subanusta are predominant approximately up to the Desyaty Seam.

The admixture in this part of the section of representatives of the genus Cordaites and of some lycopods is insignificant, alongside the typical Alykaevo aspect of the flora.

With respect to the interval of the Alchedat beds, studied by us only from core, it is difficult to establish any regularity in the flora complex. Individual blocks of this unit contain mainly the Alykaevo flora complex, or else suddenly yield impressions very reminiscent of the Chelin ones.

Cordaites Latifolius, R. cf. Derzawinii—representatives of an intermediate formation—are confined approximately to the level of the Alchedat III–V seams, not increasing in number higher in the section, where typically Alykaevo forms are again widely distributed. The suggestion naturally arises of possible combinations of different stratigraphic horizons in this part of the section as a result of the proximity of the Tomsk overthrust.

REFERENCES

1. N. M. Belyanin. Correlation of sections of the Lower Balakhon formation of the Anzher and Kemerovo districts of Kuzbass. Problems of the Geology of Kuzbass, issue 2. Izv. TPI, vol. 99, 1959.

2. M. D. Zalesskii and E. F. Chirkova. Distribution of fossil flora according to the geological sections of anthracite in the Kuznetsk and Minusinsk basins and its subdivision on the basis of this flora. Palaeontographica. Paleophytological collection of the Academy of Sciences of the USSR, 1937.

3. S. V. Meyen et al. Paleozoic and Mesozoic floras of Eurasia and the phytogeography of that time. Transactions of the Geological Institute, Academy of Sciences of the USSR, issue 208, chapters I–V, 1970.

4. S. V. Meyen. Cordaitales of the Upper Paleozoic of northern Eurasia (morphology, epidermis, structure, systematics, and stratigraphic significance). Transactions of the Geological Institute, Academy of Sciences of the USSR, issue 150, 1966.

5. G. P. Radchenko. Guide forms of the Upper Paleozoic flora of the Sayano-Altai mountain region. In: Atlas of Guide Forms of Fossil Fauna and Flora of Western Siberia, vol. 2, edited by L. L. Khalfin. Moscow, Gosgeoltekhizdat, 1955.

1. G. P. Radchenko. Phytostrat, correlation of the standard sections of the Ostrog and Balakhon parts of the Kuznetsk Series of Kuzbass. In: Atlas of guide forms of fossil fauna and flora of the Permian deposits of the Kuznetsk Basin, ed. by V. I. Yavorskii. Moscow, Gosgeoltekhizdat, 1956.

2. S. V. Sukhov, S. G. Gorelova. Assemblages of Paleozoic plants of Central Siberia and their stratigraphic significance. In: Stratigraphy of the Paleozoic of Central Siberia. Novosibirsk, “Nauka,” 1967.

3. A. Z. Yuzvitskii. Conditions of formation of the structures of the NE part of the Kuznetsk Basin (an attempt at paleotectonic analysis). Responsible editor: Doctor of Geological and Mineralogical Sciences Em. Senderzon. Novosibirsk, “Nauka,” Siberian Branch of the Academy of Sciences of the USSR, 1970.