ON THE STRATIGRAPHY OF THE PRE-DEVONIAN DEPOSITS OF THE BATENEV RIDGE

V. D. TOMASHLPOLSKAYA

(Presented by the scientific seminar of the departments of general geology, historical geology, and fossil fuels)

The present work provides a summary and analysis of stratigraphic schemes for the Precambrian and Lower Cambrian deposits of the Batenev Ridge, based on materials from our many years of work and those of other numerous researchers in the period after 1959. The preceding period of geological investigations on the Batenev Ridge was described in considerable detail by V. M. Yaroshevich (1962).

In the period 1959–1961, geologists from numerous geological institutions and research institutes worked in the territory of the Batenev Ridge, including: from the Krasnoyarsk Geological Administration (KGU), V. A. Borisov (1963), D. I. Musatov (1961), E. V. Shirokova and others (1967); from the Siberian Branch of the Academy of Sciences of the USSR, V. M. Yaroshevich (1962), I. T. Zhuravleva, L. N. Repina and others (1960, 1962, 1964); from SNIIGGiMS, M. K. Vinkman, B. G. Kraevskii, A. B. Ginzinger (1969); research staff of the Department of General Geology of TPI as part of the Sonskaya party: G. A. Ivankin, I. I. Koptev, V. E. Nomokonov, A. F. Senokos, V. A. Shipitsin, and partly the author (1966, 1968, 1971)¹.

We carried out geological investigations on the Batenev Ridge, with long interruptions, from 1932 and mainly from 1958.

As many know, the principal subdivisions in the Lower deposits described of the Batenev Ridge were distinguished by us, together with the geologists of the Krasnoyarsk Geological Administration R. B. and N. I. Karpinskii, in 1958 during the compilation of a geological map of the Batenev Ridge and the Azyrtal Range. On the basis of the results of the 1958 work, as well as our earlier work of 1932, 1935, and 1936 during training geological practices, areal detailed surveys, and thematic studies carried out by us in the period 1954–1962, and similar work in later years during training geological practices with students of the GRF of TPI, we fully developed a stratigraphic scheme for the pre-Devonian deposits of the Batenev Ridge and the Azyrtal Range.

In writing this essay we also used published works and lists of organic remains by a large group of geologists who, in the period after 1959–1960, repeatedly visited the Batenev Ridge, especially the areas where new finds of fossils became known.

¹ Dates of publication of articles on the Batenev Ridge are indicated throughout.

Precambrian

Within the territory of the Batenev Ridge these deposits are distinguished by us as part of two series: the Goldzhin and the Martyukhin. Such a subdivision is being given for the first time, as far as we know from the published literature.

Goldzhin Series. These deposits form large areas on the Batenev Ridge and are exposed in the closures of anticlinal folds. The most complete section of these deposits is exposed in the middle part of the valley of the Son River, from where they extend as a broad belt to the northeast as far as the settlement of Goldzha (whence the name of the suite was taken), and as an equally broad belt to the southwest. Deposits of the Goldzhin Suite were also established by us in many other areas of the Batenev Ridge.

Along the valley of the B. Erba, in the closure of the Loshchenkovskaya anticline, only the very upper part of the suite is exposed. In these deposits P. S. Krasnopeeva (1937) first established the presence of the algae Saralinskia, Archaeospongea, and others, which, in the opinion of the author of the collections, determines the Algonkian age of the beds containing them.

Later, by the work of the Son Party (1966, 1968), the presence of many other forms was established in these same deposits in various sectors of the Batenev Ridge, including Nevlendia, Pseudoossetia, Paleogirvanella (determinations by V. A. Shipitsyn).

According to our materials (1964), three subsuites were distinguished within the Goldzhin¹ Suite: the lower—predominantly carbonate, consisting of thin-bedded and very thin-platy, almost fissile, marly (non-bituminous) limestones of gray, light-gray, and more often dark-gray colors, with thin interbeds of sandstones and shales; the middle—predominantly effusive-terrigenous and more often terrigenous, with thin interbeds of thin-platy limestones; and the upper—again predominantly carbonate. Near the top of the suite there appear beds of anthraconic, fetid marbles and black siliceous shales. The total visible thickness of the suite is 1500 m. Its base is not established in the area studied, because the suite is cut off by a major fault. A characteristic feature of the Goldzhin Suite is the presence in it, and especially in its middle and upper parts, of numerous sill-like and, more rarely, cross-cutting bodies of gabbro-diorite and diabase composition.

The Son Party, composed of scientific workers of the Department of General Geology of the TPI (see above), which worked under contract with the Krasnoyarsk Geological Administration on the Batenev Ridge during the period 1964–1968, until 1968 called these same deposits, as did we, first the Goldzhin, and then the Poludennaya (on the basis of lithological and paleontological identity with deposits similar in stratigraphic position on the eastern slope of the Kuznetsk Alatau²); and in the published works of the same authors after 1968 these deposits were subdivided into two suites: the lower, terrigenous-carbonate—Poludennaya, and the upper, predominantly carbonate—Tyurimskaya. They combine both of these suites into the Poludennaya Series. We in principle do not object to the recognition in the deposits of the former Goldzhin Suite, and now the Goldzhin Series, of two suites, but we categorically object—

against it the name “Poludennaya Series,” which, of course, contradicts the rule of priority.

In the work of the geologists of SNIIGGIMS, the Poludennaya and Tyurim Formations are not separated out from the Goldzhin Formation. On the Azyrtal Ridge, many geologists regard the Bidzhin Formation as the stratigraphic analogue of the Goldzhin Series as a whole, and, accordingly, deposits distinguished on the Batenev Ridge as the Poludennaya and Tyurim Formations are mapped as the Bidzhin Formation (V. M. Yaroshevich, 1962; E. V. Shirokova et al., 1967). In our opinion this is entirely inadmissible, since, first, the Bidzhin Formation of the Azyrtal Ridge can, in lithology, be correlated only with the Tyurim Formation, and, second, because the paleontological characterization of the Bidzhin Formation on the Azyrtal Ridge still remains very uncertain.

Organic remains in the deposits of the Goldzhin Series are collected mainly in the Tyurim Formation and less often in the Poludennaya. In both formations their composition is characterized by several species of algae: Nevlandia, Sarania, Archaeosponia, and others, which as a whole are referred to as the Nevlandia beds. As is known to many, materials on the Nevlandia beds on the Batenev Ridge and in other areas of the Sayan-Altai folded region were reported by researchers of the Department of General Geology of TPI at the International Congress in Prague in 1967, where the question was raised of distinguishing these beds as an independent stratigraphic subdivision at the rank of a system (B. D. Vasil’ev et al., 1968).

The basis for this is their well-established stratigraphic position and the very distinctive character of the fossils, sharply different from the composition in the overlying sequence.

Thus, the separation of the Goldzhin Series from the Yenisei Series by M. K. Vinkman et al. (1969), as proposed by us, is fully justified.

The Martyukhin Series is distinguished by us as consisting of three formations: the Loshchenkovskaya, Martyukhin³, and Sorninskaya⁴.

The Loshchenkovskaya Formation—substantially effusive, with small members of terrigenous rocks—is confidently established in the limbs of the Son anticline along both banks of the Son River in its middle course; south of the village of Katyushkina; in the limbs of the Loshchenkovskaya anticline along both banks of the B. Yerba River, where it was first described by Ya. S. Edel’shtein (1926), and also in the area of the Podtemnyi ravine, in the Spirinskaya dacha in the area between the settlements of Batrad and V. Yerba, and in other places. In most cases where its base and top are exposed, it lies unconformably on the Tyurim Formation and is overlain by deposits of the higher Martyukhin Formation.

The age of the Loshchenkovskaya Formation is determined by the presence, in thin interbeds and in lenses of limestones among the effusives, of fossils represented by several species of algae of the genus Osagia, characteristic, according to Z. A. Zhuravleva (1962), of the Middle Riphean. The first collections and determinations from these limestones were made by P. S. Krasnopeeva (1937), and later by V. A. Borisov (1963) and others.

The Loshchenkovskaya Formation, in the same scope, following us, is distinguished on the Batenev Ridge by M. K. Vinkman et al. (1967) and I. I. Koptev et al. (1966, 1968, 1969), but the latter call these deposits, as on the eastern slope of the Kuznetsk Alatau, the Kul’byurstsyok Formation.

In the works of geologists of the Krasnoyarsk Geological Administration—V. A. Borisov (1963, 1964), E. V. Shirokova et al. (1967)—deposits belonging to the Loshchenkov Formation, together with the Martyukhin and Sornin formations, are called the Sosnov Formation. It seems to us that such a grouping should not be made, since in so doing stratigraphers are, in a number of cases, deprived of certainty in correlating separated territories, especially where the geological structure is complex. In particular, such a case occurs in the area of the Podtemnyi log, where the Martyukhin Formation has a complex lithological composition, sharply different from its composition in coeval sections of neighboring areas.

The Martyukhin Formation on the Batenev Ridge, in all cases where its base has been exposed, lies on the Loshchenkov Formation with a clear unconformity. At its base, geologists of the Son party establish a very considerable break—the so-called pre-Tarzhuul break, during which a weathering crust was formed.

On the Batenev Ridge, the section of the Martyukhin Formation was studied by us in different years of our work and especially in detail in 1958; later the same sections were studied by V. A. Borisov, M. K. Vinkman, and geologists of the Son party. The most complete section of the indicated formation, with base and top, is exposed in the area of the settlement of Bagrada, on the southern slopes of Mt. Kuchesteikh in the SW limb of the Bagrada syncline; a less complete one is exposed in the NW limb of the same syncline, where its base is not exposed. A fairly complete section of the Martyukhin Formation occurs on the right and left sides of the B. Erba River, in the limbs of the Loshchenkov anticline. In both these and other sections the Martyukhin Formation is represented by dolomites of light and dark color, calcareous dolomites, small beds of bedded dark limestones, and thick bodies of siliceous rocks of massive and, in places, banded texture. The most complete description of the section of the Martyukhin Formation and of its organic remains is given in the work of V. A. Borisov (1963), from which it is evident that it is characterized by fossils of Upper Riphean age in its middle part and Vendian fossils in its upper part.

Particular attention should be paid to the sections of the Martyukhin Formation in the Poperechnyi and Kardonnyi logs in the area of Lake Litvin and the Yuliya mine, as well as to its sections along the Podtemnyi log, where its lithological composition differs sharply from the stratotypical one.

As is known (1964), in the period 1959–1962 we distinguished, in the area of Lake Litvin and later in the belt between Son station and the Yuliya mine, the Litvin Formation of uncertain stratigraphic position, presumably of Lower Cambrian age.

In lithological composition—by the sharp predominance within it of bedded and massive gray and dark-gray limestones with beds of siliceous rocks, and by the presence of phosphorite-bearing rocks—it was later placed by us at the level of the Sornin Formation of the Azyrtal Range and, accordingly, was placed above the Martyukhin Formation.

Through the work of the Son party (I. I. Koptev et al., 1971), fossils (collections and determinations by V. A. Shiptitsin) were collected and identified in the stratotype of the Litvin Formation, making it possible to place the Litvin Formation at the level of the lower subformation of the Martyukhin Formation; and in the overlying strata of substantially dolomitic composition, they identified a Vendian complex of organic remains. Still higher, along the Poperechnyi log and elsewhere, above the deposits with the Vendian complex there rests unconformably, with basal conglomerates at the base, a terrigenous-carbonate sequence in which the presence has been established of algae—epiphytons and botominella—characteristic of the deposits of the Tunguzhul—

suite on the eastern slopes of the Kuznetsk Alatau (I. I. Koptev et al., 1971), and to the Ust-Kundat horizon in the section along the Kiya River.

Very interesting material for characterizing the stratigraphic position of the Litvinskaya Suite was obtained by the Son party (I. I. Koptev et al., 1966) in Pod"emnyi Log, where they assigned to the Litvinskaya Suite a limestone–dolomite member and a second, terrigenous–carbonate member of the Kureninskaya Series, on the grounds that at their base lies the effusive Loshchenkovskaya Suite, which in turn lies on the Tyurimskaya Suite, while they are overlain by dolomites with fossils of the Vendian complex, i.e., deposits corresponding to the upper part of the Martyukhinskaya Suite or the so-called Tarzhulskaya Suite of the same level on the eastern slope of the Kuznetsk Alatau (I. I. Koptev et al., 1971).

In our earlier works all these deposits were included in the Martyukhinskaya Suite and were not subdivided.

After the work of the Son party, work on the same areas of the Batenev Ridge was carried out by E. V. Shirokova et al. (1967), M. K. Vinkman et al. (1969). These sections were also studied by us, and in 1968 they were examined together with us by A. G. Vologdin, N. P. Suvorova, N. E. Chernysheva, and R. T. Bognibova.

Thus, according to the data of the Son party, at present two stratigraphic levels are clearly distinguished within the Martyukhinskaya Suite: the lower one, represented by deposits of the Litvinskaya Suite at the level of the lower subsuite of the Martyukhinskaya Suite with oncolites, catagraphs, and stromatolites of Middle–Upper Riphean age, and the Tarzhulskaya Suite—at the level of the upper subsuite of the same suite, with a Vendian complex of fossils.

However, if one takes into account that over most of the area of the Batenev Ridge deposits with the aspect of the Litvinskaya Suite are absent, it remains unclear whether the Litvinskaya Suite should be regarded as a special facies of the lower part of the dolomitic Martyukhinskaya Suite or considered part of a section removed by erosion. An indirect answer to this question may be provided by comparing the sections of the Martyukhinskaya Suite of the Batenev Ridge and the Azyrtal Range. As is known to us from our work in 1958, and also from materials published in the works of V. M. Yaroshevich (1932), G. M. Ekhanin (1970), and many others, within the Martyukhinskaya Suite on the Azyrtal Range there are distinguished thick members of substantially dolomitic composition, as well as thick members of dark bedded and massive limestones, similar, in our opinion, to the deposits of the Litvinskaya Suite in Poperechnyi Log, and members of limestone–dolomite composition similar to the deposits of the Litvinskaya Suite in Pod"emnyi Log (here a member of terrigenous rocks is also added to them). Of course, everything said above is only a very rough scheme, which must be confirmed or refuted; for this it is necessary to carry out a very detailed bed-by-bed study of the sections of the Martyukhinskaya Suite on the Batenev Ridge and on the Azyrtal Range and to find methods that will allow their correlation and thereby resolve the question of the conditions of sediment accumulation and the character of vertical movements in Martyukha time.

There is already convincing evidence for the existence of such breaks: this is the pre-Tarzhulian break at the base of the Tarzhulskaya Suite, established by geologists of the Son party (I. I. Koptev et al., 1970), which is proved by the presence of a weathering crust with sedimentary iron deposits, a basal conglomerate of pebbles of underlying rocks, and also by the fact that the Tarzhulskaya Suite lies with traces of deep erosion unconformably on the Loshchenkovskaya (Kulbyurstuyukskaya) and on the Litvinskaya Suite (our interpretation). Thus, on the right side of the Son River valley, from the materials of the Son party it is evident,

that the dolomites of the Tarzhul Formation and the effusives of the Kulbyurstyug Formation are separated by a one-hundred-meter-thick unit of dark-gray limestones with lenses and interbeds of silicilites, which, by stratigraphic position and lithology, can correspond only to the Litvin Formation. Thus, the age of the pre-Tarzhul hiatus should be specified as post-Litvin, which, apparently, explains the absence of deposits of the Litvin Formation over most of the Batenev Ridge, although there may have been other causes as well.

It is not excluded that, after detailed study of the sections of the Martyukhin Formation as a whole, several such hiatuses in Martyukhin time will be established, and accordingly several levels with weathering crusts and sedimentary deposits may be expected, the prerequisites for which are already emerging.

The Sornin Formation, first distinguished by M. K. Vinkman et al. (1969) on the Azyrtal Ridge from the Martyukhin Formation of the Yenisei Series as its upper, supra-dolomite part, is mapped less confidently within the Batenev Ridge, for tectonic contacts occur more often and, moreover, it is poorly characterized paleontologically. In the work of M. K. Vinkman et al. (1969), deposits of the Sornin Formation are shown only in the area of V. Erba—Bagrada. We established them in the area south of the Yuliya mine, between the Zverosovkhoz and the Tuva farm, where, on both limbs of the synclinal fold exposed here, the deposits assigned by us to the Sornin Formation are represented by distinctly platy and, more rarely, massive dark-gray limestones with members of silicilites; in a continuous section they are seen to overlie the dolomite sequence, which in turn is seen to overlie the effusive Loshchenko Formation. The section is crowned by light-colored massive limestones, apparently of the Usin Formation. For the present this section has not been characterized paleontologically.

Organic remains in the Sornin Formation on the Batenev Ridge have been described by M. V. Stepanova from a section on Mt. Brodovaya (M. K. Vinkman et al., 1969), and by M. V. Stepanova (1970); their age is determined as late Riphean–Vendian.

In the Sornin Formation on the Batenev Ridge, as on the Azyrtal Ridge, increased phosphatic content is established, which naturally should attract the attention of geologists, especially since increased phosphatic content is also known in deposits of the Martyukhin Formation on Mt. Kuchestekh and of the Litvin Formation on Mt. Skalistaya⁵.

Vendian—Lower Cambrian

Deposits of transitional Vendian–Lower Cambrian age were established on the Batenev Ridge for the first time by us, jointly with geologists of the Krasnoyarsk Geological Administration, R. B. and N. I. Karpinsky, in 1958 in the area of V. Erba—Bagrada and were distinguished under the name of the Bagrada Formation. At the same time we collected organic remains from these deposits: hyoliths and gastropods from the middle part of this sequence, and trilobites: Bulaiaspis taseevica Repina et al. from the top. In the lower part of the section of the named formation, organic remains were not established at that time. The results of our work were set forth in a geological report⁶ submitted to the Krasnoyarsk Geological Administration, on whose assignment in 1958 we, together with R. B. and N. I. Karpinsky,

a geological map of the Batenev Ridge and the Azyrtal Ridge was being compiled.

We reported the new finds of fauna, and especially the finds of beds with Bulaiaspis fauna, at a geological conference at TPI in 1961, and this became known to the broad geological community.

In publications, our materials on the Bagrad Formation and on the beds with Bulaiaspis fauna appeared considerably later (1963) than this was printed by V. M. Yaroshevich (1962, p. 70), by L. N. Repina (1960), and by others; therefore the facts concerning the finds of Bulaiaspis fauna are presented with major distortions. This is shown most correctly in the article by D. I. Musatov (1961).

For the convenience of the further exposition, let us recall that work in 1958 established that the Bagrad Formation occurs in the limbs of a rather simple synclinal fold (which we then called the Bagrad syncline), and also that it lies on the dolomites of the Martyukhino Formation and is overlain by archaeocyathid limestones of the Usinsk Formation, which make up the hinge of the fold; thus its age was taken to be older than Lower Cambrian.

Within the Bagrad Formation, we at that time, in 1958, distinguished two subformations. The lower subformation is represented by massive and shaly limestones with thin interbeds of dolomites and gravelites, and by interbeds of gray-black platy limestones. In these platy limestones, together with R. B. Karpinsky, we then, for the first time for the Batenev Ridge, collected gastropods similar to the gastropods of the Ust-Kundat Formation (the determinations were made by N. A. Aksarina).

To the upper subformation we assigned light-gray and pink massive and coarse-platy limestones and calcareous dolomites with thin interbeds of dark-gray bedded limestones with gnatholites. In the latter, near the very top of the upper subformation, close to the boundary with the massive archaeocyathid limestones of the overlying Usinsk Formation, we, together with R. B. and N. I. Karpinsky, collected trilobites from these beds, which I identified as belonging to the genus Bulaiaspis taseevica Repina et al. (1963).

In 1959, organic remains from the same beds were collected by I. T. Zhuravleva (D. I. Musatov, 1961), and from them L. N. Repina, in addition to Bulaiaspis, also identified olenellids (L. N. Repina et al., 1964, p. 28).

Later B. G. Kraevsky (M. K. Vinkman et al., 1969) found and identified the same trilobites in interbeds of dark-gray and black platy limestones at several levels within deposits that we call the upper subformation of the Bagrad Formation.

All the listed organic remains from the Bagrad Formation were collected by us in 1958 in the NW limb of the Bagrad anticline. In the SE limb of the same syncline, organic remains were not known at that time. Incomplete sections of the Bagrad Formation, both then and later, were established beneath the archaeocyathid limestones of the Usinsk Formation along the valley of the B. Erba River south of the village of the same name and in other places. In lithological composition and in the organic remains found, in the predominance of platy dark-gray limestones and in the presence of gnatholites in them, these deposits apparently correspond to the middle part of the Bagrad Formation.

During the period 1959—1962—1963, in the same area in the region of V. Erba—Bagrad, a geological mapping party of KGU worked under the direction of V. A. Borisov. In the course of compiling the geological map, V. A. Borisov collected organic remains from deposits of the Ba-

of the Bagrad Formation, but he calls these deposits the lower subformation of the Usin Formation. Here, as is evident in Fig. 2 (1963, p. 52), in a member of dark-gray bedded limestones lying 50–80 m above the base of the Usin Formation in the NW limb of the Bagrad syncline, V. A. Borisov collected hyoliths, and still higher, in light-colored massive limestones, multicellular algae, and together with them in some beds katagraphs and rare chiolitids. In the southern limb of the same fold A. Yu. Rozanov et al. (1960) collected, in the same sequence, archaeocyathids, i.e., of the impoverished Bazakian complex (according to I. T. Zhuravleva, 1962) or of the Belokamenian complex (according to the decision of the Interdepartmental Stratigraphic Conference of 1965).

As is known, A. Yu. Rozanov and Missarzhevsky, as well as V. A. Borisov (1963), call all the deposits named above—characterized as a whole by cellular algae, katagraphs, rare chiolitids, and archaeocyathids—“trilobite-free beds” and place them at the level of the lower subformation of the Usin Formation. We call these deposits the Bagrad Formation with the level of the Brodov and Ust-Kundat horizons.

In the area of the village of B. Erba, in the deposits of the Bagrad Formation, V. A. Borisov (1963), in addition to chiolitids from our collections, also indicates numerous epiphytons and other multicellular algae.

Almost simultaneously with the geologists of KGU and PIN, during 1960–1963 geological investigations in the area of the settlement of Bagrad were conducted by staff members of the Siberian Branch of the USSR Academy of Sciences—I. T. Zhuravleva, L. N. Repina, and others (1962, 1964). In addition to what has been said above, it should be emphasized that I. T. Zhuravleva and L. N. Repina, in the SE limb of the Bagrad syncline, in deposits overlying the “trilobite-free beds,” near the base of the overlying light-colored massive limestones of the Chesnokov (Usin) Formation in our interpretation, distinguished beds with the fauna of the Bagrad horizon (according to the terminology adopted by the ISC), i.e., beds with Mrassian trilobites and Erbinian archaeocyathids, or beds with Resimopsis below, and beds with Sayanaspis above. L. N. Repina (1964) places both of these subdivisions at the same level as the deposits of the NW limb with bulaiaspid fauna and olenellids.

The most complete geological and paleontological characterization of the Bagrad Formation is given in the works of the geologists of SNIIGGiMS (M. K. Vinkman et al., 1969, 1970); however, this work, from our point of view, requires certain comments, additions, and corrections.

First of all, let us discuss the name. The term Bagrad Formation was applied by us in a 1958 work (1963) to deposits encompassing the entire thickness from the top of the dolomites of the Martukhino Formation to the base of the massive light-colored archaeocyathid limestones of the Chesnokov (Usin) Formation. In deposits of exactly the same volume, geologists of SNIIGGiMS distinguished two formations, and applied the name “Bagrad” only to the upper part of this sequence, which introduces great confusion—especially since SNIIGGiMS geologists, under this same term at different times and in different parts of the Batenev Ridge, have distinguished sequences very different both in volume and in age, as is shown in detail in our article “Once More on the Question of the Bagrad Formation” (Izv. TPI, in press).

Let us recall that, according to the materials of the geologists of SNIIGGiMS, in deposits corresponding in volume and area of distribution to the Bagrad Formation of our scheme, they distinguish two formations: the lower—Brodov, which may briefly be called pre-gastropod, and the upper—Bagrad, from the base of the gastropod beds to the base of the beds with Sayanaspis.

The thick-platy limestones with trilobites of the Kameshkov complex, or beds with Sayanaspis, and the overlying light-colored massive limestones with the Sanashtykgol complex of archaeocyathids are regarded by the same geologists as

are assigned to the Usin Formation, and, accordingly, the beds with Resimopsis of the southeastern limb and the bed with Bulaiaspis and olenellids of the northwestern limb are placed at the same level and included in the upper part of the Bagrad Formation (in their scheme).

We accept the subdivision of the Bagrad Formation into two subformations, but, in order to avoid confusion, we propose retaining the name Bagrad for the entire formation.

We also agree that the base of the upper subformation should be drawn at the base of the gastropod-bearing dark-gray platy limestones, since a biostratigraphic boundary is also drawn fairly distinctly along this base. In the lower part, or in the so-called Brodovo Formation of M. K. Vinkman et al. (1969), collections and determinations—mainly by M. V. Stepanova (1970)—have by now established the presence of microphytolites of the Vendian complex and multicellular, probably Lower Cambrian algae, which determines their transitional Vendian–Lower Cambrian age. True, as shown by M. V. Stepanova (1970), in a bed-by-bed study of organic remains from the lower subformation of the Bagrad Formation on the Brodovy Range, predominantly multicellular Lower Cambrian algae were established in the lower members, whereas in the upper ones there are predominantly, and almost exclusively, microphytolites of the Late Riphean–Vendian complex characteristic of the Sortin Formation. These facts have not yet received an explanation.

In the upper subformation we leave only the sequence of dark bedded limestones with gastropods and the overlying light limestones with archeocyathids and Lower Cambrian algae. On the basis of its paleontological characteristics this subdivision should apparently be placed at the level of the Ust’-Kundat Formation, for which, as is known, the stratotypic section along the Kiya River is characterized by the presence of numerous gastropods, Lower Cambrian algae, hyoliths, and archeocyathids.

The deposits with trilobites Bulaiaspis taseevica Repina et al. and olenellids of the southeastern limb of the Bagrad syncline, and the beds with trilobites and archeocyathids of the Bagrad horizon (according to the ISC) of the northwestern limb of the same syncline, we assign to the Usin Formation and place them at the level of its lower subformation.

The upper subformation of the Usin Formation, with the Sanashtykgol–Obruchevka faunal complex, we assign, as before, to the Aydashevo horizon (1969). Higher subdivisions of the pre-Devonian deposits were described by us earlier.

Thus, from what has been set out above, it may be said that, in contrast to what was previously known in the published literature, we subdivide the pre-Devonian deposits into three series: the Goldzha, Martukha, and Usin. The principal criteria for distinguishing the series are complexes of organic remains. The Goldzha Series is characterized by non-Vendian fauna and other accompanying fossils, by which these deposits are reliably mapped.

For the Martukha Series as a whole, the presence of oncolites, catagraphias, stromatolites, and other microphytolites is characteristic. At the same time it is established that in the lower subdivisions there occur mainly oncolites (in the Litvinsk Formation, species of the genus Osagia are very numerous), rarely catagraphias; and conversely, in the upper subdivisions catagraphias predominate and oncolites are rare; the species composition of both is also different. The age of the entire Martukha Series as a whole is determined by most stratigraphers as Middle–Upper Riphean and Vendian.

The base of the Usin Series is drawn at the appearance of skeletal fauna. Within the Usin Series we distinguish the Bagrad Formation with two horizons: the lower—Brodovo—and the upper—Ust’-Kundat; and the Usin Formation with the “Bagrad” and Aydashevo horizons.

The age of the Brodov horizon, on the basis of the presence of microphytolites of the Vendian complex and multicellular algae, should apparently be regarded as Vendian–Lower Cambrian; the age of the Ust-Kundat horizon as early Lower Cambrian; and the age of the Usinsk Formation is determined by us as Lower Cambrian.

REFERENCES

1. V. A. Borisov. Age and biostratigraphic subdivision of the Yenisei Series of the Batenev Ridge and the Azyrtal Ridge. New data on the geology of the south of Krasnoyarsk Krai. Krasnoyarsk, 1963.

2. V. A. Borisov, A. Yu. Rozanov. New data on the biostratigraphy of the ancient strata of the Batenev Ridge. Dokl. AN SSSR, 1964, No. 158, 2.

3. M. K. Vinkman et al. Stratigraphic scheme of the Lower Cambrian and lower part of the Middle Cambrian deposits of the Altai–Sayan folded region. Tr. SNIIGGIMSa, 1962, issue 24.

4. M. K. Vinkman, A. B. Gintsinger, B. G. Kraevsky et al. Sections of the Precambrian and Lower Paleozoic of the western part of the Altai–Sayan folded region. Krasnoyarsk, 1969.

5. B. D. Vasilyev, G. A. Ivankin, I. I. Koptev, V. E. Nomokonov, K. V. Dugin, V. A. Shipitsyn. On the problem of subdivision of Upper Cambrian deposits of the Sayano-Altai region and their correlation by remains of nevadias. Results of research in geology and geography over 50 years. Publishing House of TSU, 1968.

6. G. M. Ekhanin, V. A. Shipitsyn, V. D. Kamelina. On the stratigraphy and paleontology of the Lower Cambrian of the upper reaches of the Ulen River (Batenev Ridge). Izv. TPI, vol. 217, 1971.

7. G. M. Ekhanin. Phosphate-bearing character of the Martukhino Formation of the Azyrtal Ridge (Batenev Ridge). Problems of the geology of exogenous mineral raw materials of Krasnoyarsk Krai. Krasnoyarsk, 1970.

8. Z. A. Zhuravleva. Oncolites and catagraphs in the Riphean and Cambrian of Eastern Siberia and their stratigraphic significance. Dokl. AN SSSR, vol. 158, No. 2, 1964.

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16. I. I. Koptev, V. E. Nomokonov, A. K. Semashko, V. A. Shipitsyn. On the stratigraphy of ancient strata of the region of the upper course of the Sukhaya Erba River. Izv. TPI, vol. 177, 1971.

17. I. I. Koptev, A. K. Semashko, V. A. Shipitsyn. On the stratigraphic position and age of the Litvinka phosphate-bearing sequence of the Batenev Ridge. Izv. TPI, 1976, vol. 260.

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1. M. V. Stepanova. Paleontological characterization of the ancient deposits of the area of the village of V. Erba, Batenev Ridge. Materials on the Regional Geology of Siberia. Transactions of SNIIGGiMS, Novosibirsk, 1970.

2. V. D. Tomashpolskaya, R. B. Karpinsky. On the discovery of trilobites of the genus Bulaiaspis in the Lower Cambrian deposits of the Batenev Ridge. Izv. TPI, vol. 121, 1963.

3. V. D. Tomashpolskaya. Stratigraphy and paleontology of the Cambrian of the eastern part of the Batenev Ridge. Author’s abstract of dissertation, Tomsk, 1964.

4. V. D. Tomashpolskaya. On the question of correlating the Precambrian deposits of the Batenev Ridge and the Azyrtal Range. (Abstracts for a report at the Jubilee Conference at TPI, 1971). Izv. TPI (in press).

5. V. D. Tomashpolskaya. Once more on the question of the age of the Bagrad Formation. (Report at the Jubilee Conference at TPI, 1971). Izv. TPI (in press).

6. E. V. Shirokova and D. M. Bondareva. The Sonsko-Katyushkinsky reference section of the Cambrian in the Kuznetsk Alatau. Stratigraphy of the Precambrian and Cambrian of Central Siberia. Krasnoyarsk, 1967.

7. V. M. Yaroshevich. Stratigraphy of the Sinian and Cambrian deposits of the Batenev Ridge, the Azyrtal Range, and the basin of the Bely Iyus River. Publishing House of the Siberian Branch of the Academy of Sciences of the USSR, Novosibirsk, 1962.

8. A. N. Churakov. The present state of our knowledge of the stratigraphy and tectonics of the ancient deposits of the southern part of Central Siberia. Izv. Academy of Sciences of the USSR, Division of Mathematical and Natural Sciences, nos. 1–4, 1931.

9. Ya. S. Edelshtein. Note on the geological section in the area of the settlement of B. Erba (Potekhino) in the Khakass District of the Yenisei Governorate. Collection of the Geographic-Economic Institute, Leningrad, 1926.

1. In our early works (1932) this sequence was called the “lower effusive-sedimentary sequence,” with a Lower Cambrian age, and in the work of B. N. Krasilnikov et al. (1959) it was called the Kanym Suite and its age was determined as Middle Cambrian. ↩

2. The section of the Precambrian deposits of the Batenev Ridge and of the eastern slopes of the Kuznetsk Alatau as a whole are remarkably similar both in lithology and in paleontological characteristics. ↩

3. In our earlier works it was also called the Kuchestek Formation. ↩

4. Following M. K. Vinkman et al. (1969). ↩

5. Verification, as is known, did not confirm their industrial significance. ↩

6. Funds Department of the KGU. ↩