On the Stratigraphy and Lithology of Quaternary Deposits in the Western Part of the Kuznetsk Basin

B. F. MIKHALCHENKO

(Presented by Prof. Dr. A. M. Kuzmin)

In the Kuznetsk Basin, Quaternary deposits are widespread, but the state of their study is very insufficient. To date, no scheme has been developed for subdividing these deposits that would be acceptable for the entire territory of Kuzbass; there is no sufficiently complete information on the material composition of the rocks. Ideas concerning the genesis of the loess deposits widely distributed in Kuzbass are contradictory and even disputed, etc.

The most important works that initiated the study of Quaternary deposits in Kuzbass are those of A. M. Kuzmin (1929), V. I. Yavorsky and P. I. Butov (1927), M. I. Kuchin (1931), N. N. Sokolov (1931), K. V. Radugin (1934), E. V. Shumilova (1934), V. D. Fomichev (1940), F. P. Nifontov (1951), and others.

Systematic special investigations that would cover the questions of stratigraphy and lithology of Quaternary deposits in Kuzbass sufficiently fully have not been carried out up to the present time.

The author’s study, conducted under the guidance of Prof. A. M. Kuzmin, of the lithological-mineralogical composition, chemical properties, and conditions of occurrence and distribution of the Quaternary deposits of the western part of the Kuznetsk Basin provided the material for the present article.

In the Prisalaїr belt, which encompasses the western part of Kuzbass, two separate areas are distinguished where the thickness, composition, and structure of the cover sequence of Quaternary deposits differ markedly from one another.

A. In the northwestern part of the Prisalaїr Depression, where its negative forms are most sharply expressed, the maximum thickness of these sediments reaches 80–100 meters and more.

B. Toward the southeast (toward the town of Belovo), in areas of watershed spaces, their thickness decreases to 30–50 m, and in the coal sections of the settlement of Bachaty it varies from 5–10 to 30 m.

A. Quaternary deposits of the northwestern part of the Prisalaїr Depression

The most complete section of the Quaternary deposits was penetrated by a profile of core boreholes to the northwest of the town of Leninsk-Kuznetsky, in the area of the villages of Shurinka and Pushkino. Detailed analysis and comprehensive study of core samples taken every half-meter made it possible to subdivide the sequence of Quaternary sediments into three parts.

On the variegated Tertiary clays (K. D. Zhdanova et al., 1961) the following section of Quaternary deposits is established from bottom to top (Fig. 1):

I. Highly dispersed dense and viscous clays of brown, dark-brown, and yellow-brown color, with isolated fragments of siliceous rocks, quartz, calcareous concretions, and fragments of ostracod shells. Thickness from 25 to 30 m.

II. The middle part of the section, with a total thickness from 28.5 to 32.0 m, consists of separate, regularly alternating beds of dirty-gray silty and yellowish-brown varieties of clays.

III. Loess-like yellowish-brown and grayish-yellow heavy loams and clays. Thickness from 7.0 to 16.0 m.

I. Highly dispersed brown clays of the lower part of the section form the base of the 80–100-meter Quaternary sequence filling the Prisalaire depression. Their thickness is variable and ranges from 25 to 30 m. There is insufficiently complete information on the areal distribution of these rocks. Most probably, they fill the most depressed parts of the depression.

The brown clays of the lower part of the section, unlike the overlying rocks, have high density and viscosity; they contain remains of carbonized plant detritus, fragments of ostracod shells, as well as isolated pebbles of siliceous rocks and quartz. In the air-dry state the clays crack, breaking up into separate tiles and fragments of irregular shape. The fracture is conchoidal, often splintery. When moistened, they roll into a thin long cord up to 1 mm thick. At the base of the sequence the clays become yellowish-brown, somewhat sandy, and are distinguished by the presence of small oolitic concretions, pellets, and oxides of manganese and aluminum. Occasionally they contain isolated light-colored pebbles of the underlying, more ancient clayey rocks. Throughout the entire bed the clays are carbonate-bearing. Carbonates are observed in the form of whitish punctate spots, coatings, and separate nests up to 1 cm in size. Analysis of the data from determinations of CaCO₃ shows a tendency for it to decrease toward the bottom of the bed. The CaCO₃ content changes in this direction from 11.0 to 3.4%, and its average value in the lower part of the section (based on 16 samples) is 7.5%.

The brown clays belong to highly dispersed formations. In their composition the clay fraction (\(<0.005\) mm) sharply predominates, its content in individual samples reaching 73.3%. The silty fraction (0.05–0.005 mm) is present in subordinate amounts (from 22.7 to 68.2%), and sand particles (\(>0.05\) mm) occur only as a small admixture (from 2.0 to 10%). An indirect indicator reflecting the high dispersion, and consequently the higher adsorption capacity, of the brown clays is the value of the exchange capacity, which changes downward through the section from 32.7 to 41.2 mg-equiv. per 100 g of rock. A comprehensive study of the minerals of the colloidal-dispersed clay fraction (\(<0.001\) mm), using methods of staining with organic dyes, thermal analysis, electron microscopy, and X-ray structural analysis, establishes a hydromica composition for the main mass of the brown clays. As admixtures, kaolinite, calcite, colloidal-dispersed quartz, montmorillonite (?), and organic matter are noted. The presence of the latter is also confirmed by chemical analysis by Tyurin’s method. The mineralogical composition of the detrital part of the rocks is characterized by a predominance in the light fraction of quartz (74–80%) and feldspars (10–15%). In the composition of the heavy fraction, a high content of minerals is noted.

Fig. 1. Lithological section and selected indicators of the grain composition and chemical properties of Quaternary deposits in the northwestern part of the Prisalaïr depression, borehole 314: 1—modern soil; 2—loesslike heavy loams and clays; 3—dirty-gray silty clays; 4—grayish-brown clays; 5—brown, dark-brown, and other clays; 6—variegated clays; 7—thinly laminated aleurolites of light-gray color; 8—fragments of ostracod shells; 9—rock fragments; 10—calcareous neoformations; 11—clay fraction \((<0.005\ \mathrm{mm})\), in %; 12—silty fraction \((0.05–0.005\ \mathrm{mm})\), in %; 13—sandy fraction \((>0.05\ \mathrm{mm})\), in %.

minerals of the epidote-zoisite group (38–44%), green hornblende (11–24%), and ore minerals, chiefly ilmenite, magnetite, and limonite (17–32%). Among the accessory minerals present are zircon (1.3–4.2%), tourmaline (1.3–1.5%), garnets (1.3–1.8%), apatite (up to 1%), and sphene (up to 1%). Rutile, sillimanite, staurolite, disthene, actinolite, and others occur as admixtures. In the area of the village of Shurinka, in boreholes from the above-described clays, the paleontologist O. Yu. Kachuro established the following ostracod assemblage: Candona condida O. F. Müller, Candona rastrata Br. et Norm, C. ex. krochini Bronstein, Candoniella albicany (Brady), C. dilucida Mandelstam, Cupris subglobosa Sowerby, Jlyocypris bragy Sars, Limnocythere vara Liepin, Limnocythere ornata Schw, Hyocypris brady Sars. The most typical representatives of the fossil assemblage are the species: Limnocythere vara Liepin and L. ornata Schw. O. Yu. Kachuro notes that an analogous ostracod assemblage is known from deposits of the Kochkovskaya suite \((N_2—Q_1kc)\) of the Biysk-Barnaul depression.

The lithological composition of the brown clays and the ostracod remains encountered in them indicate the formation of the distinguished sedimentary unit in lake-type basins.

II. Clayey rocks of the middle part of the section. The middle part of the section, with a total thickness from 28.5 to 32.2 m, consists of separate members of clayey rocks (Fig. 1). The latter regularly replace one another in the section and differ sharply from one another in color, which varies from grayish-brown yellowish to dirty-gray, sometimes almost black with a bluish tint. In granulometric composition, the varicolored varieties of rocks belong to clays with an average content of the clay fraction from 45 to 52%. The presence of varicolored lithological varieties of rocks of small thickness (from 4 to 13 m) indicates a rapid change in the physicogeographical setting during the period of formation of the sediments of the middle part of the section. Dirty-gray silty clayey rock members of the floodplain facies, with an increased content of ferrous oxide and sulfur, indicate a reducing environment. According to palynological analysis, they are saturated with organic remains, substantially herbaceous forms with a predominance of xerophytes. The grayish-brown rock members are mute and, in comparison with the dirty-gray silty clays, have a sharply reduced content of organic carbon. The clayey rocks of the middle part of the section are distinguished by an increased content of carbonates. When treated with 10% HCl they effervesce vigorously, and the dirty-gray silty varieties of clays, in addition, emit the odor of hydrogen sulfide. Carbonates, as a rule, are included in the finely dispersed mass of the clays and only at the base of the unit occur in the form of whitish spots, streaks, and individual nests, indicating their migration from top to bottom. The comparatively high carbonate content of the rocks largely predetermines the conditions of their environment. The pH value of aqueous extracts of the varicolored rock varieties, as in other parts of the section, reflects weakly alkaline environmental conditions and varies from 7.8 to 8.0. The absorption capacity increases noticeably toward the base of the described part of the section, where it reaches its maximum value of 35.8 mg-eq. per 100 g of rock. Study of the water-soluble salts in extracts from the clayey rocks of the middle part of the section establishes their carbonate-sulfate-chloride salinization. The content of \(HCO'_3\) in them ranges from 52.6 to 70.7 mg/l; \(SO''_4\) from 22.9 to 47.7 mg/l; \(Cl'\) from 19.2 to 40.6 mg/l. At the same time, in all cases a higher degree of salinization of the silty varieties of clays is noted.

The main mass of the clay fraction of the rocks of the middle part of the section is composed of hydromicas. Present as admixtures are kaolinite,

halloysite, possibly montmorillonite, colloidally dispersed quartz, calcite, and organic matter. Hydromicas and kaolinite, which constitute the bulk of the clayey rocks, are probably syngenetic formations. They indicate an acid and weakly acid environment under which the accumulation and formation of the clayey sediment took place. The subsequent change in environmental conditions from weakly acid to weakly alkaline could have occurred through enrichment of the rocks with carbonates, which are secondary epigenetic neoformations. At the same time, the change in the pH of the medium from weakly acid to weakly alkaline may have been one of the main causes of the decomposition of the primary hydromicaceous minerals, with their subsequent alteration toward montmorillonite. The mineralogical composition of the light and heavy fractions of the differently colored varieties of clays differs little from that of the stratigraphically overlying and underlying Quaternary rocks. The bulk of the clastic material, with particle size greater than 0.01 mm, consists of quartz (61.4–78.0%), feldspars (11.4–16.4%), and fragments of siliceous rocks (8.0–19.0%). In the heavy fraction, an increased content is noted of minerals of the epidote–zoisite group (38.4–57.4%), green hornblende (11.5–16.2), and ore minerals: ilmenite, magnetite, and limonite (14–33%). Among accessory minerals present are zircon (1.3–4.2%), garnets (0.2–1.8%), tourmaline (1.1–2.0%); more rarely rutile (0.2–1.0), sphene (0.2–1.3%), apatite (up to 0.5%), and spinel (up to 0.5%). Among the admixtures, pyroxene, alkaline hornblende, and actinolite are noted. In individual samples sillimanite, disthene, staurolite, and others occur.

The general spore-and-pollen composition of the rocks of the middle part of the section, studied by A. A. Kurbatova and L. V. Aleksandrova, is fairly uniform and is represented by typical steppe herbaceous vegetation with a predominance of xerophytic forms. Quantitative changes in the encountered forms through the section make it possible to outline a change in the physico-geographical setting of formation of the clayey deposits, which agrees with the data presented above from the study of the chemical properties of the rocks. The rhythmicity of sediment accumulation, expressed in the alternation of facies composition, was also reflected in the saturation of their spore-and-pollen spectrum, which was manifested especially in the facies of dirty-gray silty clays. The spores and pollen are dominated by typical xerophytic forms of flora: Chenopodiaceae, Artemisia, Ephedra. Sporadically, in small quantities (units of percent), pollen of woody forms is noted: Piceae, Betula, more rarely Pinus, the number of which decreases upward through the section. The steppe spore-and-pollen complex distinguished in the second part of the section approaches to some degree the Middle Pleistocene complex of the Pre-Altai plain described by O. V. Matveeva (1960). Taking into account the facies features of this unit, it should be regarded as alluvial deposits of broad, swampy floodplains.

III. Loess-like heavy loams and clays. Stratigraphically higher, on the dirty-gray silty clays, lie the loess rocks of the upper part of the section, in which two horizons of buried soils are observed. The latter are not persistent along strike and are noted only in the northeastern part of the profile, where they were exposed by borehole 315. The boundary of transition from the dirty-gray silty clays to the loess deposits is clearly expressed and emphasized by a sharp change in the color of the rocks. In granulometric composition, loess-like heavy loams and clays of yellowish-brown and grayish-yellow color are distinguished in the upper part of the section. They are characterized by a very high (from 50 to 72%) content of particles of the silty fraction. Among the latter, in all cases, coarse-

silty particles (0.05–0.01 mm) quantitatively predominate over fine dust (0.01–0.005 mm).

The most clearly expressed loess-like appearance (macroporosity, carbonateness, dustiness, looseness) is shown by loams and clays down to a depth of 4–6 m. At the base of the layer they become noticeably dense, somewhat sandy, ferruginized, and less carbonate. According to L. K. Larionov (1959), the structure of the rocks is defined as granular-aggregate. Under the microscope, the main mass of the rocks consists of aggregated areas filled with finely dispersed clayey and carbonate material, iron hydroxides, and quartz. The prevailing sizes of the mineral clastic particles vary from 0.01 to 0.056 mm. The clastic particles are not rounded; they are angular and irregular in shape.

The mineralogical composition of the loess-like rocks does not differ qualitatively from that of the stratigraphically underlying, more ancient Quaternary formations, and, both in the section and throughout the entire area studied, has an analogous assemblage of mineral species. The bulk of the clastic material is made up of minerals of the light fraction: quartz (72–78%), feldspars (13–18%), and fragments of siliceous rocks (7–8%). In the composition of the heavy fraction, the epidote-zoisite group predominates (48–55%), along with green hornblende (14–15%) and ore minerals: ilmenite, magnetite, and limonite (19–30%). Zircon (2.9–3.7%), apatite (up to 1%), rutile (up to 0.2%), garnet (0.2–1.3%), tourmaline (1.2–1.7%), and others are noted as admixtures. In the colloidally dispersed clayey part of the loess rocks, minerals of the hydromica type predominate. As admixtures, colloidally dispersed quartz, kaolinite, calcite, organic matter, and others are noted. The predominantly hydromicaceous composition of the colloidally dispersed clayey part of the loess rocks is also confirmed by data from determination of their absorption capacity. The value of the exchange capacity, obtained by the method of L. I. Kulchitskii (1960), does not exceed 28.1 mg-eq. per 100 g of rock. The above-mentioned lithological varieties of loess rocks are noticeably carbonatized. The carbonate content (by calcimeter), recalculated as CaCO₃, varies from 7.4 to 8.9%, with an average value, from 11 samples, of 8.2%. The carbonates are secondary epigenetic neoformations and, as a rule, enter into the composition of the finely dispersed mass of the rocks. Not infrequently they form whitish coatings, occur as thin veinlets and diffuse spots, cover the walls of pores with crusts, etc. The comparatively high carbonateness of the loess rocks largely predetermines slightly alkaline environmental conditions, changing the pH value from 7.6 to 7.9.

Study of the bulk chemical composition of the loess rocks establishes the similarity and close quantitative values of the indices obtained with those of the underlying, more ancient Quaternary formations. The quantitative values of the principal rock-forming oxides in the section of the Quaternary sedimentary sequence vary as follows: (in %) SiO₂ 53.77–58.60; Al₂O 13.26–14.84; TiO₂ 0.67–0.70; Fe₂O₃ 2.30–4.60; FeO 0.57–2.65; MnO 0.08–0.11; total S 0.0–0.29; CaO 5.01–7.67; MgO 2.31–2.72; Na₂O 1.61–1.88; K₂O 2.13–2.37; P₂O₅ 0.1–0.13. The value of the silica coefficient

$$ \left(K_i=\frac{\mathrm{SiO}_2}{\mathrm{Al}_2\mathrm{O}_3}\right) $$

reaches 4.4, which (according to M. I. Lomonovich, 1955) indicates the accumulation of colloidal quartz, intensive degradation of the loess rocks, and increased climatic humidity. The homogeneity of the chemical composition of the entire Quaternary sedimentary sequence agrees with the data on mineralogical composition and testifies to the constancy of the source areas of the weathering products that entered the Kuznetsk Basin during Quaternary time.

Determination of water-soluble salts in extracts from loess rocks indicates their carbonate–sulfate–chloride salinization. The content of HCO₃′ in them ranges from 52.4 to 78.6 mg/l; SO₄″ from 34.7 to 53.2 mg/l; Cl′ from 15.3 to 24.9 mg/l. The total amount of water-soluble salts in the loess rocks varies from 165.4 to 211.9 mg per 100 g of rock. If the results obtained for the determination of water-soluble salts are compared with published data for other regions of the Soviet Union (A. K. Larionov, 1959; F. A. Nikitenko, 1963, et al.), their quantitative values are found to be somewhat lower. This feature of the loess rocks of the Kuzbass territory can probably be explained by the fact that they formed and exist under conditions of moderate moisture, rather than an arid climate, and that, as a result, the sediments underwent considerable washing and leaching.

Spectral analysis of the loess rocks, carried out by A. D. Glazunova, shows that the average content of microelements both vertically and horizontally is approximately constant. The most important microelements of the loess rocks are: (in %) Ca > 1, Na > 1, Ti = 0.1, Mn = 0.03, V = 0.01, Ni = 0.01, Cr = 0.006, Co = 0.001, Cu = 0.001–0.003, Pb = 0.001. Mo, Sn, Zn, and others are noted as admixtures.

B. Cover Quaternary Deposits of the Watersheds

The structure of the cover sequence of Quaternary deposits on the watersheds differs noticeably from the sediments characterized above, which occupy the lowest parts of the Prisalaïr depression. The section of the cover deposits on the watersheds begins with a horizon of unsorted sandy–gravel–pebble sediments (Fig. 2). Their thickness is variable and ranges from 0.5 to 10 m. They lie on an eroded surface of Paleozoic rocks and are replaced upward in the section by bluish-gray and brown clays up to 17 m thick. According to data from geologists of the WSGU (A. M. Mysina et al., 1963), channel sandy–gravel–pebble deposits can be traced as an elongated belt southeast from the city of Leninsk-Kuznetskii toward the city of Belovo, where they are gradually replaced by deposits of silty clays and loams of the floodplain facies.

The most complete section of the deposits of the floodplain facies is exposed by open-pit coal workings in the settlement of Bachaty. Here, thinly laminated dirty-gray and blue silty clays occur at the base of the rocks of the Quaternary complex and have a thickness of 2 to 15 m. They contain decomposed remains of herbaceous and woody vegetation, microfauna of gastropods, and sometimes bones of mammals occur in them. Among the latter, we were fortunate enough to find, in the blue clays, a skull of Bison priscus and a tooth of Elephas primigenius¹. Palynological studies of the blue clays establish a similarity of the spore–pollen forms of vegetation with the above-described spectrum of silty varieties of rocks in the northwestern part of the Prisalaïr depression. According to the conclusion of A. A. Kurbatova and L. V. Aleksandrova, the spectrum is dominated by the family Chenopodiaceae and the genus Artemisia, which occur in approximately equal quantities and together constitute 50% of the total composition. The other half of the spectrum consists of pollen of Gramineae, Compositae, Cyperaceae, Plumbaginaceae, Ephedra (single grains), mixed herbs (families Polygonaceae, Crucifera, Convolvulaceae, Coryophyllaceae, Labiatae, Rosaceae, etc.). Pollen of arboreal forms is encountered: pine, spruce, more rarely birch.

¹ According to the determination by I. G. Pidoplichko.

Woody forms amount to only a few percent, being markedly inferior in the spectrum to herbaceous vegetation.

The gray and brown clay varieties occurring higher in the section, together with the sandy-gravel-pebble material described above and the deposits of the floodplain facies, make up the lower part of the section of the cover sedimentary sequence on the watersheds. Study of the principal chemical characteristics of the clayey rocks of the lower part of the section establishes their weakly alkaline environmental conditions. The pH value ranges from 8.0 to 8.7.

The calcium carbonate content varies from 1.6 to 14.7%. The exchange capacity ranges from 19.9 to 31.0 mg-equiv. per 100 g of rock. In mineralogical composition the clayey varieties differ little from the stratigraphically overlying loess deposits. The bulk of these rocks is formed by clay minerals of the hydromica type. Admixtures include kaolinite, colloidally dispersed quartz, beidellite, organic matter, and others. In the clastic part of the rocks (fraction 0.01–0.25 mm), quartz occupies the dominant position (43–50%); subordinate amounts contain feldspars (16–27%), fragments of siliceous rocks (21–22%), and carbonates (8–40%). In the composition of the heavy fraction, the predominant minerals are those of the epidote–zoisite group (33–62%), green hornblende (5–16%), ore minerals: ilmenite and magnetite (6–24%), and limonite (3–31%). In addition, leucoxene (2–3%), anatase (1–4%), tourmaline (1–2%), zircon (2–5%), apatite (2–3%), and garnets (1–2%) are present. Pyroxenes, sphene, spinel, corundum, sillimanite, staurolite, kyanite, and others occur in very insignificant amounts.

The upper part of the cover complex of Quaternary deposits on the watersheds and slopes of the Prisalaïr depression is composed of eluvial-deluvial loess-like loams and clays, divided by buried soils into three horizons (Fig. 2). Since the loess rocks of all three horizons are macroscopically quite similar and proved to be paleontologically barren, the following set of features was used for their subdivision:

1. Structural-textural features, identified in describing cores and exposures.

2. Features of the granulometric, mineralogical, and chemical composition of the loess rocks. In this, the buried soils in the section, which have important stratigraphic significance, were analyzed especially carefully. Particularly sensitive characteristics from this point of view are the pH of aqueous extracts of the rocks, carbonate content as determined in a calcimeter, the exchange capacity of the rocks, and others. The increased content of humic substances in buried soils provides them with a higher adsorption capacity, and this is reflected primarily in the value of the absorption capacity. The latter in buried soils always has higher values, whereas the carbon dioxide (CO₂) content decreases sharply and, as a consequence, the pH value decreases.

The distinguished horizons of loess rocks differ from one another in structural-morphological features, variable moisture content, different degree of subsidence, etc.

The upper loess horizon is composed of heavy silty, more rarely medium and light loams of yellowish-gray and light-brown color. They are distinguished by high macroporosity, have a loose structure, and in individual well-drained areas of the watersheds possess

subsidence properties (F. P. Nifantov, 1960). The thickness of this horizon varies from 2 to 8–10 m.

The rocks of the middle horizon are represented by heavy silty loams and clays with a thickness from 3 to 6–11 m. They have a brownish-gray color, are noticeably ferruginized, and are characterized by increased moisture, less pronounced macroporosity, and the absence of subsidence properties.

The deposits of the lower horizon display all the features of a loesslike appearance and, in granulometric composition, belong to silty

Fig. 2. Lithological section and selected indicators of grain-size composition and chemical properties of Quaternary deposits in borehole 1572 (Belovo district, Ubinskaya coal prospecting area): 1—modern soil; 2—loesslike heavy loams; 3—buried soil; 4—loesslike silty clays; 5—light-brown and gray clays containing an admixture of sandy-gravelly material; 6—unsorted sandy-gravelly-pebble deposits; 7—siltstones of light-gray color; 8—calcareous neoformations; 9—fragments of burrowing animals; 10—rock fragments; 11—clay fraction (< 0.005 mm), in %; 12—silty fraction (0.05–0.005 mm), in %; 13—sandy fraction (> 0.05 mm), in %.

heavy loams and clays. As an admixture, they sometimes contain isolated angular and weakly rounded fragments of siliceous rocks. The thickness of the lower horizon varies from 4 to 6–8 m.

In the composition and quantitative ratio of minerals of the heavy and light fractions, the loess rocks of all three horizons are similar. In se-

Upon separation from the total suspension of particles of 0.01–0.25 mm and their subsequent separation in heavy liquids, the minerals of the heavy fraction amount to only 0.1–1.5%. The remainder of the suspension belongs to the light fraction. The bulk of the clastic material of the loess rocks consists of quartz (43–55%), feldspars (18–31%), carbonates (15–30%), and fragments of siliceous rocks (4–12%). In the heavy fraction, the predominant minerals are those of the epidote–zoisite group (37–44%), ore minerals, mainly ilmenite and magnetite (13–20%), limonite (2–10%), zircon (3–6%), apatite (2–4%), tourmaline (1–3%), micas (2–3%), leucoxene and anatase (3–5%), and garnets (1–2%). As accessories there occur tremolite, rutile, sphene, spinel, sillimanite, staurolite, kyanite, and others. In the clay fraction, hydromicas predominate. As admixtures, colloidally dispersed quartz, kaolinite, calcite, feldspars, and organic matter are always present; beidellite and possibly montmorillonite, developing on hydromicas, are also noted.

The brevity of this article does not allow us to provide sufficiently complete illustrations of the sections or to examine the factual material in greater detail. But an analysis of what has been stated above makes it possible to draw the following conclusions:

1. The investigations carried out on the lithological-mineralogical composition of the rocks are of great importance for subdividing and correlating Quaternary deposits and for reconstructing the paleogeography of the Quaternary period.

2. The methods used for the comprehensive study of Quaternary deposits had previously been tested by us for the adjacent territory of the Tom–Ya watershed (B. F. Mikhalchenko, 1962, 1964). The results of the present work show that they have fully justified themselves and that the data obtained by them can be used for correlating sediments over large areas.

3. The most effective characteristics that can be used for the lithological subdivision of sediments (especially for identifying horizons of fossil soils in the study of cores) are data on the grain-size composition of the rocks, the pH of aqueous suspensions, the content of calcium carbonate and humus in the rocks, exchange capacity, and others.

4. The three horizons of loess rocks first distinguished in Kuzbass correlate well with those previously established for the territory of the Tom–Ya watershed and indicate the existence of three different-time epochs of loess formation.

5. The uniformity of the mineralogical and chemical composition of the Quaternary sequence of sediments in the examined territory of Kuzbass indicates the constancy of the source areas of the weathering products that entered the Kuznetsk Basin during Quaternary time.

REFERENCES

A. K. Larionov et al. Loess Rocks of the USSR and Their Construction Properties. Gosgeoltekhizdat, 1959.

M. I. Lomonovich. Colloidal minerals, microaggregateness, and subsidence of the loess of the Zailiysky Ala-Tau. In: Problems of the Geology of Asia, vol. II, Publishing House of the Academy of Sciences of the USSR, 1955.

B. F. Mikhalchenko. Characteristics of the mineralogical composition and structure of the loess rocks of the Bogashevo area. Transactions of NIIZhT, issue XXVIII, Novosibirsk, 1962.

B. F. Mikhalchenko. Lithological-mineralogical composition and chemical properties of loess rocks and older Quaternary deposits of the western slope of the Tom–Ya interfluve. In: Materials on the Geology and Mineral Resources of Western Siberia. Tomsk, 1964.

B. F. Mikhalchenko, A. A. Kurbatova, L. V. Aleksandrova. On the stratigraphy and lithology of Quaternary deposits of the southwestern part of Kuzbass. Abstracts of a report to the All-Union Conference on the Study of the Quaternary Period, Novosibirsk, 1964.

F. A. Nikitenko. Loess rocks of the Novosibirsk Ob Region and their engineering-geological characteristics. Proceedings of NIIZhT, issue XXXIV. Novosibirsk, 1963.

F. P. Nifantov. Engineering-geological characteristics of loess-like rocks of the Belovo district of Kuzbass. Collection of Scientific Works, vol. VII, TISI. Tomsk, 1960.

G. A. Sulakshina, B. F. Mikhalchenko. Structural features and subsidence of loess rocks of the western slope of the Tom–Yaya watershed. News of Higher Educational Institutions. Geology and Exploration, 1964, No. 2.