Toward a Discussion of the Stratigraphy of the Coal-Bearing Deposits of the Kuznetsk Basin

L. L. Khalfin

Twice during the past three years, controversial questions of the stratigraphy of the coal-bearing deposits of Kuzbass have been submitted to the judgment of broad circles of geologists interested in these questions—at interdepartmental conferences in the city of Leninsk-Kuznetskii (July 1954) and in Leningrad (January 1956). Twice at these conferences “each side” presented, for collective consideration by the most interested and competent specialists, the data and arguments at its disposal in support of its point of view. And twice the participants in these broad conferences, with great unanimity, reached decisions on the most important and debatable questions of this dispute.

In this way, such substantial changes were introduced into the previously accepted stratigraphic scheme of Kuzbass (known as the 1934 scheme) that it acquired a new character, and its adoption may be regarded (as we shall show below) as the beginning of a new stage in the geological study of the basin.

It is therefore, at the very least, puzzling that in the recently published atlas of the guiding forms of Kuzbass [2] the stratigraphy of the basin is set forth as though there had been no broad and fruitful discussion of these questions, and as though no important decisions on them had been adopted by authoritative conferences. (Let us immediately note one date: additions to the original text of this atlas were made, at least, up to June 1955, as is attested by the footnote on p. 273.)

In the preface to this atlas [2, p. 4] the important significance of precise stratigraphy for the geological prospecting work being carried out is discussed, that is, for the preparation of new mine fields and, consequently, for increasing coal production in Kuzbass. But precisely because the scheme resurrected in the atlas mentioned can no longer serve these purposes—moreover, it has become an obstacle to their achievement—work was undertaken to correct it. And for this same reason one cannot pass over the attempt to present, even for the present day, the scheme adopted before 1954 as the “generally accepted stratigraphic subdivision of the Upper Paleozoic coal-bearing deposits” [2, p. 6].

Let us give a brief historical note, necessarily very compressed. Without touching upon the initial stages of the study of Kuzbass and without dwelling on the various schemes of stratigraphic subdivision of the basin’s coal-bearing deposits proposed by different authors at different times, let us note three principal stages in the development of the stratigraphy of Kuzbass.

The first of them was the result of work carried out in Kuzbass under the direction of L. I. Lutugin and ending with the proposal of a scheme consisting of seven industrially coal-bearing and barren series. In this scheme, which in its time played a certain positive role, an incorrect sequence of coal-bearing and barren strata was given, as was clarified by subsequent, more detailed work.

As a result, chiefly, of the work of S. V. Kumpan, V. D. Fomichev, and V. I. Skok in the Kemerovo district, this error was eliminated, the correct sequence of the series was clarified, and a new scheme was proposed, approved at the 1934 conference in Leningrad. With certain changes and corrections, sometimes substantial (for example, the abolition of the Krasnoyarsk series), but not altering its essence and not eliminating its main shortcomings, this scheme remained generally accepted up to the 1954 conference [5].

In essence, this scheme was purely lithological; biostratigraphic data were practically absent in its development. The boundaries of the subdivisions of the 1934 scheme were either sliding (drawn along the first and last workable coal seams) or so indefinite that, for example, two coeval facies for a long time figured in this scheme as series of different ages (the Krasnoyarsk and Ilyinsk series). As a result, sections of deposits from different districts of Kuzbass were correlated incorrectly according to this scheme. This was its chief defect, the negative influence of which kept increasing as prospecting and exploration work in the basin expanded and as the requirements for its quality rose.

It is quite obvious that such a situation could not continue indefinitely, and, as new materials accumulated, in particular paleontological ones, the moment inevitably approached and had to come for a revision and reconstruction of the scheme on a new biostratigraphic basis, which also inevitably had to be accompanied by a refinement of the indexing of the series. That moment arrived: it was the 1954 conference. But just as naturally, there were people to whom this reconstruction of the 1934 scheme seemed excessive, who preferred the customary scheme to the new proposals. In this vein a struggle of opinions unfolded at the 1954 conference and again at the 1956 conference.

Before illuminating the results of these conferences, let us note that the defects of the 1934 scheme were not in any way specific. They are inherent in purely lithostratigraphic schemes in general, with arbitrary (sliding) boundaries. By way of illustration we shall cite only one example, relating to the stratigraphy of the Permian deposits of the Donbass, which were also subdivided in a purely lithological manner, and the boundaries between series were drawn by the same method: along the first limestone bed, along the first bed or thin bed of salt, etc.

As the very detailed studies of L. P. Nesterenko [7] showed, this led to a gross distortion of the true stratigraphic and facies relationships: the true position of the boundaries between series in a number of districts was different from what had been accepted earlier; one stratigraphic interval (up to 200 m thick) was repeated twice in the column (in different series); it turned out that industrially salt-bearing deposits of one district in another did not contain salt beds, etc.

A completely analogous picture is observed in Kuzbass as well. According to the scheme that they are trying to revive in the aforementioned atlas, the industrially coal-bearing deposits of the Osinovskoye, Baidaevskoye, Chertinskoye, Raspadskoye, and a number of other fields are assigned to the Erunakovskaya series, whereas in reality they partly belong to the Ilyinskaya

...suite, devoid of workable coal seams in other areas. The independent Usyat subseries, a commercial coal-bearing one in the southern areas of the Kuzbass and replaced by low-thickness deposits without workable seams in the north, is erroneously correlated with the upper parts of the Kemerovo subseries, etc.

These and similar errors and inaccuracies are inevitable and unavoidable when using the 1934 scheme: they are generated directly by the very nature of schemes of this kind. Conversely, the 1954 scheme eliminated, or makes removable, such errors, since this scheme is biostratigraphic and permits precise correlation of sections from different parts of the basin. The schemes of 1934 and 1954 are different in their character, and we are entitled to characterize the latter as a new scheme, although one genetically connected with the 1934 scheme. With the adoption of the new scheme, for the first time in the study of the Kuzbass there appeared the possibility of exact parallelization of sections from different areas of the basin, which is a necessary prerequisite for paleogeographic reconstructions and for the scientific orientation of prospecting and exploration work for coal, oil, and possibly other useful minerals. For this reason we consider that the adoption of the new scheme marks the beginning of a new stage in the study of the Kuzbass, when a deeper knowledge becomes possible of the history of the formation of this basin and, consequently, of the regularities in the distribution of useful minerals in its deposits.

Thus, the 1954 scheme is a biostratigraphic scheme. All its subdivisions have received a sufficiently definite paleontological characterization, and their boundaries are established by the replacement of faunal and floral assemblages. Thus, the study of pelecypods, which led to the establishment of a number of stratigraphic and facies assemblages, makes it possible, quite precisely and independently of coal seams of varying thickness, to establish the boundaries between the Lower Balakhon and Upper Balakhon, between the Upper Balakhon and Kuznetsk, between the Kuznetsk and Ilyinsk, and between the Ilyinsk and Erunakov suites.

In this way the previously accepted correlations between the suites were corrected (in some cases substantially), although the sequence of the suites remained the same, since it had been correctly established in the preceding period. But the age indices of the suites were also revised and substantially changed, beginning with the Ostrog suite, to which in the former scheme an Upper Carboniferous age had been assigned, whereas now its assignment to the upper part of the Lower Carboniferous is generally accepted.

Thus, the principal features, the essence of the 1954 scheme, are the refinement and biostratigraphic substantiation of the boundaries of its subdivisions, their paleontological characterization, and their refined geological age.

This scheme has already been published and commented upon more than once [3; 6]; therefore here we shall confine ourselves to presenting it in comparison with the 1934 scheme (Table 1) and shall dwell on those purely technical changes that were introduced into it at the 1956 conference.

In the 1954 scheme, the subordination of stratigraphic subdivisions long used in the Kuzbass was retained: suite, subseries, series. But already in 1955 the All-Union Conference on general questions of stratigraphic classification excluded from the system of regional subdivisions the term “series” (as a term of free usage) and proposed “to apply the following auxiliary regional stratigraphic subdivisions in the order of their subordination: series, suite, member, bed,” with the prefixes “super-” or “sub-” for subdivisions of intermediate rank [8, p. 7].

In accordance with this decision, at the Conference on the unification of the stratigraphic schemes of Siberia, held in 1956, those subdivisions

Table 1.

of the 1954 scheme, which were called formations, it was decided to call subformations, and to raise the subformations to the rank of independent formations.

As series for the Upper Paleozoic part of the section, under the names Balakhon and Kolchugin, those largest subdivisions were adopted which had long since been established in Kuzbass as the principal stages of sedimentation and coal accumulation and which, for example, in the works of M. F. Neuburg, appeared under the names “formations I and II.” They fully correspond to that tectono-stratigraphic content which series must possess as natural units of regional stratigraphy.

Triassic and Jurassic deposits of Kuzbass, bounded above and below by tectono-denudational breaks, also fully meet this requirement; they too were assigned the significance of series (under the names Mal’tsevo and Tarbagan).

At the 1956 conference, some names of subdivisions were changed. Thus, considering the double name “Upper Kolchugin (Erunakov)” inconvenient, it was decided to retain for this formation only the old name “Erunakov”; in connection with this, and instead of “Lower Kolchugin,” the old name “Il’in formation” was adopted, while the corresponding Il’in member (now subformation) was renamed Kazankovo-Markino.

With regard to all these renamings it is necessary to bear in mind the following: the scope of the Erunakov and Il’in formations in the new scheme and in the 1934 scheme is different: from the former Erunakov formation, in a number of districts, its lower part has been separated out, entering into the Uskat subformation of the Il’in formation [3, pp. 24–26].

Even at the 1954 conference, a number of participants [5, reports by N. M. Belyanin, O. A. Betekhtina, and others] insisted on dividing the Gramoteino member (subformation); at the 1956 conference this question was raised again, and a preliminary decision was adopted to provisionally distinguish the upper part of the Erunakov formation as a separate Tailugan subformation, with subsequent refinement of its scope and lower boundary. Finally, in response to the wishes of representatives of the Ministry of Geology, it was decided to divide the Ishanovo-intermediate subformation into the Ishanovo and the intermediate subformations for their separate mapping, although at present this is possible only in a few districts of Kuzbass.

All these changes quite obviously have a technical character, in no way affecting the essence of the 1954 scheme: neither the age indexing nor the position of the boundaries of its subdivisions underwent any changes.

After the discussion indicated above, the 1954 scheme was approved in the form in which it is presented in Table I.

The transition from the former scheme to the new one is natural and logical: this is the usual path of improving local and regional stratigraphic schemes.

The conferences of 1954 and 1956 showed that the number of opponents of the new scheme is quantitatively insignificant; however, the atlas of guide forms of Kuzbass shows that they have not laid down their arms and intend to defend their hopeless positions. In defense of the former scheme and against the new one they put forward two arguments: a) sliding boundaries (along coal seams of workable thickness) are “practically very convenient” [2, p. 16]; therefore the changes adopted by the 1954 conference are not dictated by necessity [12, p. 132]; b) these changes are “not scientifically substantiated” [ibid.].

The first of these arguments hardly requires detailed analysis: for all regions, in particular—for all coal-bearing basins, a biostratigraphic substantiation of the subdivision of deposits is considered desirable and even necessary, but for Kuzbass, for some reason, sliding boundaries prove to be...

turn out to be more convenient. To what “practical conveniences” they lead, we showed above with several examples relating to the coal-bearing deposits of Kuzbass and the salt-bearing deposits of Donbass.

The initiative for revising the old stratigraphic scheme of Kuzbass came from production workers, and the 1954 conference was convened by the trust “Kuzbassuglegeologiya.” In the preface to the materials of the 1954 conference, the head of the Main Coal-Geology Administration of the Ministry of the Coal Industry of the USSR, T. T. Litvinov, wrote: “The previously adopted stratigraphic scheme of Kuzbass, which in its time played a large positive role, with the expansion of geological-prospecting work came into conflict with new materials. Without serious improvement it could no longer serve as a scientific basis for the proper planning and orientation of prospecting and exploration work in the basin, necessary for the development of coal mining in the areas most favorable for industrial development. As was noted at the conference, some conceptions of the basin’s stratigraphy did not contribute to the proper direction of prospecting work in the basin” [5, p. 3].

The second argument—about the scientific groundlessness of the new scheme—is an attempt to discredit the decisions of two broad, representative, and authoritative conferences. Let us see how this is done by taking as an example the most acute and disputed question, on which the opponents of the new scheme show the greatest persistence—the question of the age of the Ostrog Formation (and, consequently, of the overlying formations). Let us recall that an age of the very uppermost parts of \(C_3\) was assigned to this formation on the basis of the conclusions of A. P. Rotai and M. E. Yanishevsky concerning the brachiopod fauna of this formation, although paleobotanists had long considered it more ancient.

In the Kuzbass atlas of index forms A. P. Rotai writes: “since 1932 up to the present time no new data on the fauna have appeared that would compel a change in the point of view previously adopted by A. P. Rotai on the age of the Ostrog Formation” [2; 11]. It is difficult to believe that these lines were written by a person who attended the 1954 conference.

At that conference, in the report by A. P. Rotai [9], three categories of arguments were adduced in favor of an Upper Carboniferous–Lower Permian age of the Ostrog Formation: a) the presence of forms that he considers to be index forms; b) certain general features of the fauna; c) certain broad general-geological correlations and parallels.

In opposition to them, new paleontological materials concerning the Ostrog Formation, accumulated after 1932 (mainly in recent years), were presented at the conference: by V. B. Trizna—on bryozoans, N. I. Novozhilova—on phyllopod crustaceans, and L. A. Kovalenko—on pollen and spores.

In the report by R. N. Benediktova [4], step by step all the arguments of the supporters of an Upper Carboniferous age of the formation were examined and refuted, and the erroneous identification of certain local species of spiriferids with the Permian species Spirifer kimsari Bion and Spirifer darwini Morris was demonstrated.

Finally, speaking in the discussion, T. G. Sarycheva reported that among the brachiopods of the formation she had discovered such a typical Lower Carboniferous form as Productus striatus Fischer, and that the productids referred to the species Pr. cora Orb. had been reidentified as Productus kokdscharensis Groeb. Moreover, new paleobotanical data and new data on the insect fauna of the overlying formations [5] exclude an Upper Carboniferous age for the Ostrog Formation.

Thus, at the 1954 conference new, very diverse paleontological materials were reported, in agreement indicating its Lower Carboniferous age. At the conference there was not found even one—

...a certain person, to whom the entire body of these new materials would have seemed unconvincing, and A. P. Rotai himself, under the pressure of these new materials, stated in his concluding remarks that there could now be no other solution to the question than assigning the Ostrog Formation to the Lower Carboniferous.

The question of the Lower Carboniferous age of the Ostrog Formation at the 1954 conference was decided quite unanimously. True, at the 1956 conference an attempt was made to revise this decision, but it ended in complete failure: the participants in the conference unanimously, with two abstentions, rejected the proposal to subject the age indices of the formations adopted in 1954 to any changes.

In light of what has been set forth, the above-cited assertion by A. P. Rotai that there were no new materials is, at the very least, surprising: one may disagree with these materials, one may dispute them, but one must not tell readers that there are no new materials! And let us answer at once the possible explanations that all this was written before 1954: in the atlas, not only do the footnotes contain references to materials up to mid-1955 inclusive, but directly in the text [2, p. 16] there are remarks precisely about the 1954 conference.

Only lack of space forces me to confine myself to the single example considered above and not to cite other cases of the suppression in the atlas of materials that refute the indexing of the formations adopted in it. And despite such an extremely unobjective and one-sided approach to the matter, “new trends” break into this atlas and shatter old conceptions. Let us show this with several examples.

One of the main sections of the atlas is the section on spores and pollen; the author of this section, E. M. Andreeva, indicates that the spore-pollen complexes of the Lower Balakhonka Formation “are dated as Middle and Upper Carboniferous” [2, p. 216].

The author of the second large section of the atlas, G. P. Radchenko, of the seven phytostratigraphic zones that he distinguishes in the Upper Paleozoic part of the Kuzbass section, assigns three zones (encompassing the Ostrog and Lower Balakhonka formations) to the Carboniferous [ibid., pp. 120, 121]. The reader is left to guess how these conclusions can be reconciled with the assertion that “the age of the Ostrog Formation cannot be older than the Upper Carboniferous, and that of the Balakhonka Formation—Lower Permian” [ibid., p. 272].

We see that the old scheme, which apparently found its last refuge in the Kuzbass atlas, is saved neither by the “protective” cover (“Atlas of index forms... of the Permian deposits of the Kuznetsk Basin”) nor by the stubborn desire of some of its contributors to pretend that new materials do not exist.

In this paleontological atlas, the attitude toward paleontological materials is wholly determined by the extent to which they confirm or refute preconceived views. This can be shown by a number of examples; let us cite one of them, concerning the paleobotanical materials of G. P. Radchenko: in some cases his phytostratigraphic constructions are set against paleofaunistic ones as exemplary [2, p. 273], while in others they are declared unnatural [ibid., p. 11].

The desire at all costs to fit the paleontological materials into the former scheme leads to direct distortions; in particular, this applies to the pelecypod fauna, and I, as the author of the corresponding section of the atlas, must point this out. The table of the distribution of pelecypods [2, p. 55] has been “reworked” in such a way that it has become simply incomprehensible, and the stratigraphic position of ten forms (out of 31) is shown incorrectly in it.

Further, the name of the Late Balakhonka fauna was in due course by me...

[10] identified a highly characteristic association of forms, distributed in the very upper parts of the Upper Balakhon Formation, corresponding to the Usyat Subformation. But this subformation does not fit within the framework of the former scheme and cannot be distinguished by means of “convenient” criteria (coal seams of workable thickness), since in the south of the basin it is industrially coal-bearing, while in the north it is entirely devoid of workable seams. Therefore the pelecypod association mentioned as guiding for the Usyat Subformation is assigned in the atlas to the Kemerovo Subformation [2, p. 33], which is completely at variance with reality.

This example is indicative: as has already been said, the Usyat Subformation cannot be distinguished by the methods on which the development of the 1934 scheme was based, but it has a quite definite paleontological characterization and can be distinguished in any district of the Kuzbass by flora and by pelecypod fauna. Is it surprising that V. I. Yavorsky is disappointed in this fauna and in the results of its study, as he writes twice in the atlas [2, p. 6 and p. 273]? V. I. Yavorsky prefers biostratigraphic boundaries that are gradual; this is a matter of taste, but in reply to his statement that the study of pelecypods “gave less precise data with respect to the boundaries of the formations that had been distinguished” [2, p. 6], I shall cite only one reference (incidentally, one known to V. I. Yavorsky): the boundary between the Upper Balakhon and Kuznetsk formations (i.e., precisely the upper boundary of the Usyat series) is established with the utmost precision by the replacement of the Late Balakhon fauna by the Early Kuznetsk fauna: 110 m above seam VI Inner in the Prokopyevsk district, 65 m above seam VII Inner in the Kiselevsk district, and 70–75 m above the Kemerovo seam in the Kemerovo district.

In general, the boundaries between formations, according to the pelecypod fauna, are in most cases drawn in the most precise manner; the replacement of faunal assemblages at formation boundaries has recently been characterized by me [11]; there is no need to repeat it here.

Only by deliberately ignoring the varied materials obtained by a large number of production and scientific workers can one assert that the changes introduced into the former scheme are not scientifically substantiated.

The 1954 conference, when considering questions of the stratigraphy of the Kuzbass, had at its disposal incomparably, immeasurably more extensive materials (and not only paleontological ones) than the 1934 conference. Thus, thanks to the large volume of prospecting and exploration work carried out, the geological structure of many deposits and districts was clarified in detail—deposits and districts about which, twenty years earlier, there had been only very schematic information, or no data at all.

The paleontological materials on the Kuzbass before 1934 were more than meager: in the study of the flora only the very first steps had been taken; all the literature on pelecypods, with the exception of a few completely outdated notes, dates from the period after 1934; for other groups of fauna (including the brachiopods of the Ostrog Formation), a fundamental revision of the available materials was carried out, or new, at times very substantial, materials were obtained (for example, on insects, bryozoans, phyllopod crustaceans, and others).

All these materials were covered in the reports of the 1954 conference.

This article was written immediately after the publication of the Atlas of Guiding Forms of the Fossil Flora and Fauna of the Permian Deposits of the Kuzbass (1956) and represents a reply to the attempt to revive

the stratigraphic scheme of Kuzbass, which was abolished by the decision of the Conference on the Stratigraphy of Kuzbass (1954).

It now seems necessary to make several additional observations in connection with the appearance of O. L. Einor’s article “Correlation and Age of the Principal Sections of the Upper Paleozoic of the Pechora–Kuznetsk Coal-Bearing Region” (Sovetskaya geologiya, 1958, issue 1), which, in the author’s own words, represents an “expanded version” of a report delivered at the Interdepartmental Conference on the Development of Unified Stratigraphic Schemes of Siberia in January 1956 in Leningrad.

In this article, only its very beginning and very end are of interest; we shall dwell on them below, noting first that at the 1956 conference the stratigraphic scheme of Kuzbass adopted by the 1954 conference was confirmed in all its fundamental provisions, in particular with respect to the age indexing of the formations [5, pp. 248–249]. It was precisely on the latter question, and especially on the question of the age of the Ostrog Formation, that discussion again unfolded at the 1956 conference: three participants in the conference (A. P. Rotai, O. L. Einor, V. I. Yavorsky) persistently, but quite unsuccessfully, defended the former point of view on the Upper Carboniferous age of this formation. Having exhausted their arguments in two days of debate, A. P. Rotai and O. L. Einor (V. I. Yavorsky was absent) stated at the crowded concluding session of the Section of the Middle and Upper Paleozoic that they would refrain from accepting a decision on the question of the age of the Ostrog Formation.

O. L. Einor begins his article with the assertion that in the Upper Paleozoic, in very different structures over an enormous territory from the Pechora Basin to the Vilyuy syneclise and from Taimyr to Eastern Kazakhstan, “there were similar geotectonic conditions.” This is, to say the least, a bold and original conception (though one corresponding to the spirit of the entire article): for some incredible reason, structures always and everywhere fundamentally differing in their inherent tectonic regime in the Upper Paleozoic, it turns out, were characterized by similar geotectonic conditions.

Further, on the following pages, O. L. Einor adapts various data relating to the geology of different regions to this conception. In doing so, however, no new facts are cited that would not have been known to the participants in the conferences of 1954 and 1956 and would not have been taken into account by them in developing the stratigraphy of Kuzbass and, in particular, in determining the age of the Ostrog Formation. O. L. Einor himself formulated the results of all his reasoning at the end of the article so plainly that we need only quote: “I would still consider the Early Permian age of the brachiopod complex of the Ostrog Formation most probable. Only proceeding from the entire body of paleontological materials concerning the Ostrog Formation do I favor its Middle–Upper Carboniferous age. At the same time, one cannot regard as excluded a Lower Carboniferous age for its lower part, as Sakmarian—the upper half (from the upper bed with marine fauna).” The undoubted quality of this formulation is its great elasticity, leaving the reader the possibility of a wide choice depending on his tastes and inclinations.

CITED LITERATURE

1. “Atlas of the Guide Forms of Fossil Fauna and Flora of Western Siberia,” vol. II. Gostoptekhizdat, Moscow, 1955.

2. “Atlas of the Guide Forms of Fossil Flora and Fauna of the Permian Deposits of the Kuznetsk Basin.” Gostoptekhizdat, Moscow, 1956.

1. Belyanin N. M. and Khalfin L. L. Stratigraphic scheme of Kuzbass adopted by the 1954 conference (general characterization). In: Problems of the Geology of Kuzbass, vol. 1, 1956.

2. Benediktova R. N. On brachiopods and the age of the Ostrog Formation. Ibid.

3. Problems of the Geology of Kuzbass, issue 1. Materials of the Second Conference on the Stratigraphy of Coal-Bearing Deposits. Ugletekhizdat, Moscow, 1956.

4. Molchanov I. I. and Khalfin L. L. Stratigraphy of the coal-bearing deposits of the Kuznetsk Basin (1954 scheme). Soviet Geology, No. 45, 1955.

5. Nesterenko L. P. Stratigraphy of the Permian deposits of the Donets Basin. Proceedings of the Academy of Sciences of the USSR, Geological Series, No. 7, 1956.

6. Resolution of the All-Union Conference on General Questions of Stratigraphic Classification. Leningrad, 1955.

7. Rotai A. P. The Lower Carboniferous and the Ostrog Formation of the Kuznetsk Basin. In: Problems of the Geology of Kuzbass, vol. 1, 1956.

8. Khalfin L. L. Lamellibranch mollusks of the coal-bearing deposits of Kuzbass. Proceedings of the Mining-Geological Institute of the West Siberian Branch of the Academy of Sciences of the USSR, issue 10, 1950.

9. Khalfin L. L. Introduction to the biostratigraphy of the coal-bearing deposits of the Kuznetsk Basin. In: Problems of the Geology of Kuzbass, vol. 1, 1956.

10. Yavorskii V. I. On the question of the stratigraphy of the Kuznetsk Basin. Soviet Geology, No. 45, 1955.

Tomsk Polytechnic Institute
named after S. M. Kirov