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© 2020 Elsevier Ltd and INQUA Eurasian loess-paleosol sequences provide continuous records of global change in mid-latitude Northern Eurasia. The loess-paleosol sequence of West Siberia located in the central part of the mid-latitude Eurasian loess belt extending from West Europe to Yakutia is an outstanding paleoclimate archive in Northern Asia. The stratigraphy has been best documented on the left bank of the Ob River, in the so-called Ob Loess Plateau. This study focuses on the stratigraphy of the most complete Middle-Late Pleistocene loess-paleosol sequence at the Belovo section. The suggested high-resolution model of the Belovo Late Pleistocene stratigraphy is based on magnetic and sedimentological proxies and is correlated with other Eurasian loess records and with the global marine δ18O stratigraphy. The enviromagnetic signal at Belovo Loess-paleosol sequences shows a transitional pattern comparable with both typical Eurasian loess magnetic records. Detailed paleopedological interpretations of the magnetic and sedimentological data from the Belovo section have important implications for appropriate linking different Late Pleistocene climates and environments of other the well-known Eurasian loess provinces.

We have analyzed the modern status of the chronostratigraphic differentiation of the loess–paleosoil series in southwestern Siberia and the results of luminescence dating of the reference section of the Altai low mountains near the settlement of Krasnogorskoe. A complete series of the Middle and the Late Pleistocene levels of paleosoil formation is distinguished. Six new dates were obtained for the section by optically stimulated luminescence (OSL) and infrared stimulated luminescence (IRSL), and two samples were measured simultaneously, using quartz and feldspar, to control the light exposure and the reliability of the absolute age determined. The results obtained indicate the formation of the lower Berdsk paleosoil during the last interglacial period, which corresponds to Marine isotopic stage (MIS) 5e, and two dates of the underlying loess (127 and 149 ka BP) confirm that the age of this strata correlates with MIS 6. The age of the overlying Iskitimsk pedocomplex and of the horizon of Yeltsovsk loess is also substantiated by four OSL dates (48–39 and 39–25 ka BP). The final chronology confirms the previously elaborated chronostratigraphic scheme of the loess–paleosoil series in southwestern Siberia, which is based on a detailed morphological characteristic of paleosoils.

The loess-paleosol sequence of the Krasnogorskoye section in the low-altitude area of the northeastern Altai Mountains, can provide a yardstick for estimating the age of the Paleolithic sites and reconstructing environmental and climatic changes. Its correlation with the respective sequence of the southern part of the West Siberian Plain is evaluated. Five pedocomplexes are studied in detail, evidencing the evolution of the Middle and Late Pleistocene soil formation from the Shadrikha interglacial to the Karga interstadial. Buried soils of the Shadrikha, Shipunovo, Koinikha, and Kazantsevo warm stages formed under a climate that was warmer and more humid than today. After the Kazantsevo interglacial, both the range and the frequency of climatic oscillations show marked changes. It is demonstrated that the warm stages of this interval differ from the earlier ones by lesser warming and shorter duration by a cooler and more arid climate. Seven loess horizons dividing pedocomplexes are established. Nonmetric and metric analyses of quartz sand grains support the eolian origin of loess horizons under cryoarid conditions. The size of grains in the Late Pleistocene portion of the Krasnogorskoye section attests to the intensifi cation of the loess processes. Higher magnetic susceptibility during the cool stages and higher frequency-dependent susceptibility during the warm stages evidence marked climatic oscillations. After the Kazantsevo interglacial, the amplitude fades and the pattern of paleoclimatic signal recorded by the magnetic properties of loess and paleosol in the section are close to the “Alaskan” type.

This paper presents new data on the structure and the lithological, pedological, paleontological, and paleomagnetic features of the Middle and Upper Quaternary sediments in the Peschanaya River valley, the foothills of northwestern Altai. Those horizons contain a loess-soil sequence and sediments relating to two Middle Pleistocene interglacials. On the basis of palinological characteristics of one of the Middle Pleistocene interglacials, the succession of fl oras during the respective stages is reconstructed. The Middle Pleistocene interglacial fl oras of Western Siberia are compared with that reconstructed on the basis of the Karama site, evidencing marked differences. The fl ora around Karama included broad-leaved taxa that were absent during the Middle Pleistocene interglacials of western Siberia, when apart from modern arboreal taxa, only cold-resistant broad-leaved ones were present (Tilia, Corylus, Ulmus, and Juglans). The Karama fl ora resembles the last western Siberian thermophilic fl ora––Barnaul, which existed during the long climatic warming of the Early Pleistocene, corresponding to the Tiglian in northwestern Europe (2.23–1.59 Ma BP). Since the beginning of the Middle Pleistocene, interglacial fl oras of western Siberia have resembled modern ones. In terms of phytocenotic and palaeoclimatic features, Middle Pleistocene interglacial environments of western Siberia display a sharp contrast with those of Barnаul and Karama.

As a result of cluster and discriminant data analysis, the objects are distributed among different classes represented in the multidimensional space of parameter values. At the next stage, it is relevant to use the results obtained in various applications. The most frequently solved task is the diagnostics of a newly received object when the class of the object is determined through parameter values. In terms of a data view model, the problem can be reduced to determining a domain in parameter space, the new object belonging to this domain. The solution to this problem depends on the way the data analysis results are described and presented. Previously the graphic data model was considered to describe the domains separated by surfaces in the multidimensional space. Moreover, a constructive approach was proposed to describe an error in the representation of the boundaries, making it possible to take into account the experimental data errors. The mathematical model proposed in the given article is used to develop a domain identification algorithm by the parameter values in the multidimensional space. The proof of correctness and the estimation of computational complexity are provided for the algorithm. The results obtained make it possible to use the algorithm to calculate various characteristics of objects: state, intervals of existence, etc.

The data presented introduce substantial changes into Quaternary stratigraphy, paleogeography, and the geological history of the Altai Mountains. The purpose of this investigation was thorough study of block accumulations in the Chuya and Katun river valleys. The new data shed light on the structure of these deposits, their composition, the geomorphological and stratigraphic position, and the morphology of blocks. The revealed morphological features of individual blocks imply their glacial origin.

Debatable aspects of age, stratigraphic position, and natural conditions of the oldest stratified Early Paleolithic Karama site in the Altai Mountains are critically revised. The extensive geological, stratigraphic, and paleontological data allow the sufficiently well-substantiated assumption that accumulation of the Karama Formation and existence of the Early Paleolithic Karama site correspond to a long period of climate warming in the Early Pleistocene correlated with the Tiglian of northwestern Europe lasting from 2.23 to 1.59 Ma. The age model proposed for the formation of the Quaternary sequence in the Anui River valley, which includes the artifact-containing deposits of the Karama site, seems to be the most probable one proceeding from interpretation of available data on the geological structure, stratigraphy, paleomagnetism, and paleontological and lithological properties of Upper Cenozoic sequences observable both in the Anui River valley and in Siberian areas adjacent to the Altai mountainous region.

The data presented in this work introduce substantial corrections into the Upper Cenozoic stratigraphy and geological history of Gornyi Altai. They provide evidence for the most ancient Early Pleistocene glaciation in this region. This follows from finds of faceted boulders buried in the Bashkaus Formation. Pale-omagnetic investigations revealed in the latter a wide zone of negative polarity corresponding to the Matuyama Chron in the magnetostratigraphic scale and made it possible to correlate the formation with the Lower Pleistocene in the standard stratigraphic scale. It is shown that global cooling at the beginning of the Quaternary Period stimulated development of glaciation on the southern slope of the Kuraiskii Range exceeding in size its present-day scale.

The Pleistocene loess-soil sequence from West Siberia has provided a continuous record of Quaternary climate change in Northern Asia. The Middle-Late Pleistocene loess-paleosol stratigraphy of West Siberia has become recently a subject of discussion after a considerable revision was suggested by equating the Shipunovo pedocomplex to the Late Pleistocene stage 5 (MIS 5) instead of the previous correlation with the Middle Pleistocene stage MIS 9. The revision, however, was made using data from a single sampled section (Marble Quarry site), without proper reference to the local geology, to links of the loess and soil units traceable between the Lozhok and Marble quarries, and to deposition hiatuses. We compare the loess-soil stratigraphy at the Marble Quarry site (Iskitim area, Novosibirsk Priobie Plateau, upper Ob reaches) with the continuous record of the nearby Lozhok Quarry and evidence from boreholes in the quarry bottom to show that the Shipunovo pedocomplex does correlate with MIS 9. MIS 5 is the time of the Berdsk complex formation. The two complexes have many features of difference: thickness and maturity of soil profiles; thickness and expression of humus and illuviation horizons; distribution of calcium carbonate concentrations within the soil profiles; patterns of soil formation processes and cryoturbation, and stratigraphy. The Lozhok Quarry section, comprising five pedocomplexes intercalated in loess, is continuous and almost free from hiatuses. The Marble Quarry section in the Berd high terrace, in contrast, does not contain some stratigraphic units (including the Berdsk and Koinikha pedocomplex), the gaps being indicated by coarse sand and gruss at the base of loess layers. Therefore, the study has demonstrated the previously suggested Pleistocene loess-soil stratigraphy in southeastern West Siberia.

The authors argue that the beginning of human occupation of West Siberia in the Paleolithic was restricted by its southern part (the Altai Mountains and the Kuznetsk Basin). The advance to plains and initial colonization of northern areas started at the Late Pleistocene, the Karginsky interstadial. Landscape and environment dynamics during the Karginsky, the Sartan, and the Last Glacial periods have been characterized. Human colonization of the majority of the areas lying in the southeastern and central parts of the West Siberia Plain occurred during the Sartan epoch. The chapter summarizes the data on the Late Paleolithic sites indicating their chronology and industry type.

This article presents the results of multidisciplinary studies conducted at Chagyrskaya – an Upper Pleistocene karst cave in the northwestern Altai where Middle Paleolithic stone tools and fossil remains of Neanderthals were found. Taphonomic aspects of the site are addressed, and results of science-based analyses including radiocarbon and paleomagnetic dating are presented. The deposits are similar to loess-like Upper Pleistocene loams of Western Siberia. Among the Middle Paleolithic industries of the Altai, the Chagyrskaya industry is paralleled only by that of Okladnikov (formerly Sibiryachikha) Cave. Both represent a local Middle Paleolithic Mousteroid facies, named Sibiryachikha after the eponymous site.

A complete loess–soil record of the Brunhes chron from West Siberia was correlated it to continuous global climate records. The structure of pedocomplexes in the loess–soil sequence mirrors the structure of warm stages in the marine δ18O stratigraphy, in Antarctica and in the Baikal archive. The North Asian climate events documented in loess–soil sections correlate well with 20-, 40-, and 100-ka cycles of the global records. Both the loess–soil sequence and the global climate records show stable correlation between temperature changes and intensity of atmospheric circulation.

A comparison of Neopleistocene soils in complete loess-soil sequences in southern West Siberia has shown a distinct trend in the evolution of soil formation and climate during warming stages. The Late Neopleistocene climate changes differed in amplitude and frequency from those in the Early and Middle Neopleistocene, when the territory of southern Siberia was dominated by a temperate warm and humid climate. The amplitude and frequency of climatic fluctuations changed significantly after the Kazantsevo interglacial. Warming stages at that time were much shorter, colder, and more arid. Early Neopleistocene soils are represented by Meadow and Meadow-Chernozem soils, formed upon heavy clay sediments in semi-hydromorphic conditions under wet meadow vegetation. They show intense humus accumulation, gleying features, R2O3 enrichment and lessivage. In the Middle Neopleistocene, Chernozem soils with double humic profiles and Grey Forest–Chernozem poligenetic soils formed on porous loess-like sediments. In the Late Neopleistocene, Chernozems and Grey Forest soils have reduced weakly differentiated profiles and humus horizons, which are half as thick relative to the soils of the previous stages. Correlation of the Neopleistocene loess-soil sequences in West Siberia with the oxygen isotope record from deep oceanic sediments shows that climate change in mid-latitude regions is in line with the global change controlled by Earth's orbital parameters. Climate change occurs in 100 kyr cycles that correspond to major glacial–interglacial alternation.

This paper presents new paleomagnetic results on Cenozoic rocks from northern central Asia. Eighteen sites were sampled in Pliocene to Miocene clays and sandy clays of the Zaisan basin (southeastern Kazakhstan) and 12 sites in the upper Oligocene to Pleistocene clays and sandstones of the Chuya depression (Siberian Altai). Thermal demagnetization of isothermal remanent magnetization (IRM) showed that hematite and magnetite are the main ferromagnetic minerals in the deposits of the Zaisan basin. Stepwise thermal demagnetization up to 640–660 °C isolated a characteristic (ChRM) component of either normal or reverse polarity at nine sites. At two other sites, the great circles convergence method yielded a definite direction. Measurements of the anisotropy of magnetic susceptibility showed that the hematite-bearing sediments preserved their depositional fabric. These results suggest a primary origin of the ChRM and were substantiated by positive fold and reversal tests. The mean paleomagnetic direction for the Zaisan basin (D=9°, I=59°, k=19, α95=11°) is close to the expected direction derived from the APW path of Eurasia [J. Geophys. Res. 96 (1991) 4029] and shows that the basin did not rotated relative to stable Asia during the Tertiary. In the upper Pliocene–Pleistocene sandstones of the Chuya depression, a very stable ChRM carried by hematite was found. Its mean direction (D=9°, I=46°, k=25, α95=7°) is characterized by declination close to the one excepted for early Quaternary, whereas inclination is lower. In the middle Miocene to lower Pliocene clays and sandstones, a stable ChRM of both normal and reverse polarities carried by magnetite was isolated. Its mean direction (D=332°, I=63°, k=31, α95=4°) is deviated with respect to the reference direction and implies a Neogene, 39±8° counterclockwise rotation of the Chuya depression relative to stable Asia. These results and those from the literature suggest that the different amount of rotation found in the two basins is related to a sharp variation in their tectonic style, predominantly compressive in the Zaisan basin and transpressive in the Siberian Altai. At a larger scale, the pattern of vertical axis rotations deduced from paleomagnetic data in northern central Asia is consistent with the hypothesis of a large left-lateral shear zone running from the Pamirs to the Baikal. Heterogeneous rotations, however, indicate changes in style of faulting along the shear zone and local effect for the domains with the largest rotations.