A study of landscape and climate changes over the last 14000 cal year BP in Northern Mongolia is presented in the paper, based on a comprehensive analysis of friable sediments and seventeen AMS 14C dates from two sections in the Orkhon River basin. The Orkhon and Darkhan sections are located in similar geomorphological conditions on the first above-floodplain river terrace but have some differences. The Orkhon section is located directly at the riverbed, not far from the mountain range, while the Darkhan section is located in a ravine that cuts the terrace surface, at a distance from the river and mountains. This geomorphological difference causes the completeness and complexity of the paleoarchives in the studied sections. Both sections have a thick soil-sediment sequence with several heterochronous paleosols separated by sediments of varying genesis (mainly aeolian and fluvial). The paleosols were formed during periods of slow relief transformation, reflecting the most optimal bioclimatic conditions. The interlaying sediments (sandy-silty layers) display the phases of soil degradation due to frequent droughts and increased aeolian processes, with sporadic and catastrophic rainfalls (horizontally and lenticularly layered strata with a large amount of detritus and gravel). According to our data, the soil profile that was formed in the Late glacial period is characterized by a humid type of soil formation, and according to palynological data, meadow vegetation was widespread. In the Early Holocene, there was one stage of optimal conditions (increased heat and moisture) proper for soil development in Northern Mongolia. In the Middle Holocene, there are at least three stages. Finally, there were two stages with increased climate humidity in the Late Holocene. In the Early Holocene, Northern Mongolia had more humid forest-steppe conditions, which were replaced by steppe conditions in the Middle Holocene, when the climate changed more significantly. An expansion of forest vegetation (pine forests), probably on the northern slopes, is noted in the pollen spectra of Middle Holocene soils. Steppe and semi-desert landscapes predominated. Several stages of enhanced aridization were reconstructed: about 3800-4000, between 8400-8000 years BP. In the Darkhan section, the period of 8394-2775 years was a significant hiatus in soil formation. About 50 cm of sand accumulated over 5600 years, and there are no soils in this layer. Plausibly, the surface was essentially denudated before the second paleosol formation. At the same time, the Orkhon section accumulated aeolian sediment more than 70 cm thick. It suggests the existence of a period of severe droughts at the end of the Middle Holocene (after 3000 years BP). In the Late Holocene, climate humidification was reconstructed, when meadow steppes predominated again. The uppermost paleosol in the Darkhan section was formed in the second half of the Late Holocene.

Loess deposits are widely spread all over Eastern Europe, extending as far south as the Sea of Azov and the northern Black Sea. For many decades these regions have been noted for series of key sections. However, despite prolonged investigations, a lack of absolute dating and detailed lithological data has left many unresolved problems in the correlation of the regional stratigraphic schemes. In this study, integrated studies were undertaken on the loess-paleosol sequence exposed on the northern coast of the Taman Peninsula, separating the Sea of Azov from the Black Sea. The exposure in the coastal scarp near Cape Pekla was sampled in detail for standard lithological and stratigraphic analyses, and for the first time, detailed data on the sediments lithology and petromagnetic properties were obtained, as well as the first optically stimulated luminescence age estimates. The data lead us to conclude that the formation of continental series exposed in the Pekla section started at the beginning of the Middle Pleistocene. There are five well pronounced buried soil complexes (PS 1–5) exposed in the sequence, covering sedimentation from the Middle Pleistocene to the present day. We attribute two lower paleosols (PS 4 and PS 5) to two main warm intervals of the Middle Pleistocene – MIS 9 and MIS 13, and the Kamenka interglacial paleosol, correlated with MIS 7 from other parts of the Azov loess area, is represented in the Pekla section by a sand layer formed at the time of the marine transgression dated to interval 220–280 ka (MIS 7). The upper soil horizons (PS1, PS2 and PS3) developed between 20 and 220 ka. The Pekla section contains a considerable proportion of sand fraction – presumably, due to active eolian processes that developed in immediate vicinities of sources of the material. The paleosol characteristics and the structure of loess horizons in the Pekla subaerial series differ considerably from the well described loess-paleosol series of the Northern Azov Sea coasts. In all probability, this region of the Taman Peninsula belongs to a specific province located south of the North Azov loess-soil province.

Loess and loess-like soil formations are distributed in 3 regions across Mongolia. The lower part of the Orkhon and Selenge river basin in North Mongolia is the main loess area and another two are located in east Mongolia, in the Onon and Ulz river basins and the Khalka Gol river area. Loess-like soil covers a total of 109,000 sq.km or 6.95 per cent of the territory of the country. Loess soil properties have been studied on the basis of 8 sections and 83 samples. Fine sand fraction is predominant in the loess granulometric composition and its mean value is 51.3 per cent, and silt content mean value is about 34.9 per cent. A typical loess is a non-stony silt or fine sand, but there are also gravel loess. The average stone gravel content in the loess sediments is 8.1 per cent, sandy loess doesn’t contain any stone, but coarse fragment is high (20.5 per cent) in gravel loess. There is higher sand content (57.0 per cent) in gravel loess as compared to sandy loess (47.4 per cent). Mongolian loess soil average calcium carbonate content is 2.9 per cent, and Organic Matter (0.93 per cent) is higher than Chinese loess (0.41 per cent). Using 14C isotope data analysis and sediment properties we have tried to define the loess stratigraphy. Lower base section of fine sand silty loess sediments or about 1-3 meter thick layers were mostly formed during the mid-Holocene (7.5-3.0 ka) period. Upper parts of silty loess or 1.0-0.7 meter top layers were accumulated in the late Holocene (3ka BP to present) period. Kastanozem topsoil humus horizon (15-30 cm) formation starts at 1.5-1.0 ka BP. Mid-Holocene period probably witnessed the most active loess accumulation with a warm and dry windy condition prevailing. Sandy loess with a thickness of 1-2 meters predominate in Mongolia, and in some places loess thickness reaches up to 20-30 meters.

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Recent revision of the Pleistocene glaciation boundaries in northern Eurasia has encouraged the search for nonglacial geological records of the environmental history of northern West Siberia. We studied an alluvial paleosol-sedimentary sequence of the high terrace of the Vakh River (middle Ob basin) to extract the indicators of environmental change since Marine Oxygen Isotope Stage (MIS) 6. Two levels of the buried paleosols are attributed to MIS 5 and MIS 3, as evidenced by U/Th and radiocarbon dates. Palynological and pedogenetic characteristics of the lower pedocomplex recorded the climate fluctuations during MIS 5, from the Picea-Larix taiga environment during MIS 5e to the establishment of the tundra-steppe environment due to the cooling of MIS 5d or MIS 5b and partial recovery of boreal forests with Picea and Pinus in MIS 5c or MIS 5a. The upper paleosol level shows signs of cryogenic hydromorphic pedogenesis corresponding to the tundra landscape, with permafrost during MIS 3. Boulders incorporated in a laminated alluvial deposit between the paleosols are dropstones brought from the Enisei valley by ice rafting during the cold MIS 4. An abundance of eolian morphostructures on quartz grains from the sediments that overly the upper paleosol suggests a cold, dry, and windy environment during the MIS 2 cryochron.

Integrated paleogeographic studies have been performed on the loess and soil sequence in the lower reaches of the Orkhon R., northern Mongolia. The samples were taken continuously through the sequence and studied using a broad assortment of field and laboratory analyses. There are five paleosols exposed in the section under study crowned with the present-day soil and separated from each other by loess horizons or proluvial-deluvial deposits. The dating by radiocarbon proved the soil development beginning from the early Holocene. The two lower soils (PS4 and PS5) formed at that interval are noted for the minimum salinity and a considerable content of carbonates. The soils dated to the middle Holocene (PS3 and PS2) contain the least proportion of organic matter and increased salinity, which may be attributed to a dryer climate (even at optimum intervals) than in the early and late Holocene. In common with the present-day soil, the PS1 buried soil is characterized by negligible (or absent) salinity, and a noticeable accumulation of organic matter and carbonates indicative of favorable warm and relatively wet conditions. All the pollen assemblages indicate the dominance of grass vegetation; it may be safely suggested that open meadow and steppe landscapes, occasionally replaced by semi-deserts, prevailed in the considered region during the Holocene.

Проведены палеомагнитные исследования микулино-ранневалдайских (МИС 5) почв и отложений Среднерусской возвышенности. Отбор образцов для измерения магнитной восприимчивости К и определения естественной остаточной намагниченности Jn выполнялись в непрерывной колонке палеопочв и лессов мощностью 4,5 м, формировавшихся в первую половину позднего плейстоцена (128–65 тысяч лет назад). В верхней части ранневалдайских отложений с возрастом по ОСЛ – 115±7 ka BP (МИС 5d), установлен эпизод обратной намагниченности, вероятно, связанный с концом экскурса Блейк. Завершение экскурса Блейк совпало с похолоданием, наступившим после завершения микулинского межледниковья. Величина магнитной восприимчивости К максимальна для гумусового горизонта межледниковой рышковской палеопочвы (МИС 5e) и его педоседимента, имеющего следы сильного пожара. Распределение К по профилю палеопочв аналогично с распределением для сходных по генезису современных почв. Paleomagnetic studies of the Mikulino-Early Valdai (MIS 5) soils and sediments of the Central Russian upland were carried out. Sampling for measuring the magnetic susceptibility to and determining the natural residual magnetization of Jn was performed in a continuous column of paleosols and loess with a thickness of 4.5 m, formed in the first half of the Late Pleistocene (128–65 thousand years ago). In the upper part of the Early Valdai sediments with an age of OSL – 115±7 ka BP (MIS 5d), an episode of reverse magnetization was established, probably associated with the end of the Blake excursion. The end of the Blake excursion coincided with a cold snap that occurred after the end of the Mikulino interglacial. The magnitude of the magnetic susceptibility to is maximal for the humus horizon of the interglacial Ryshkovo paleosol (MIS 5e) and its pedosediment, which has traces of a strong fire. The distribution of K in the paleosol profile is similar to the distribution for modern soils with similar genesis.

In this paper we focused on the micromorphology of the Late and Middle Pleistocene paleosols exposed in twelve loess-paleosol sequences sections in the central part of the East European Plain. Each studied paleosol complex known as Mesin (MIS 5), Kamenka (MIS 6 (8) - 7 (9)), and Inzhavino (MIS 8 (10) - 9 (11)) pedocomplexes (PCs) consists typically of two members, the earlier - main - phase of the soil development taking place during an interglacial, and the later one - at the subsequent interstadial time. Interglacial paleosols formation is associated with the thermal optimum of climatic macrocycles and corresponds to conditions close to modern in the territory under consideration. Interstadial paleosols formation characterizes the intervals within the glacial period, accompanied by an increase in heat and moisture. However, the heat supply of such intervals did not reach modern level in this region (Velichko and Morozova 2015). As follows from the analysis of the soil micromorphology over the studied area, the soil microstructure experienced notable changes under changing latitudinal zonality. During the interglacial periods clay coatings and Fe-Mn pedofeatures dominated the soil microfabric; in the south loess-paleosol sequences coatings are in negligible quantities, Fe-Mn pedofeatures decrease in amount, and carbonate pedofeatures appear instead. In the microfabric of the interstadial paleosols, Fe-Mn pedofeatures are abundant, but unlike interglacial paleosols, the coatings are rare. Basically, the coatings are humus-clayey in composition, but in the more southern sections coatings are absent.

The loess-paleosol sequence exposed in the Beregovoye section (southwest of the Crimean Peninsula) has been thoroughly studied. Detailed analysis of the paleosol morphology, physical properties and chemical composition, micromorphology and other characteristics made it possible to identify types of paleosols formed in the Pliocene and Pleistocene. The results obtained gave us an insight into the climate and environments of the past. According to them, the climate of the Pliocene optimum was extremely hot and wet, and the soil zonality was hardly pronounced practically over entire Central and Eastern Europe. At the final phase of the Pliocene the climate became drier, though the rainfall amount was still greater than in the Holocene. During the Early Pleistocene the soil development followed the Mediterranean type, the climate being still warm, though less humid than in the Pliocene. There are two peaks of catastrophic changes in the evolution of the climate and environments distinctly traceable in the Beregovoye section: first – corresponding to the global change recorded between the Pliocene and Pleistocene and second, falling on the initial phase of the modern (Holocene) soil formation.

The micro- and macromorphological studies performed on the loess-soil sequences in the south of the East European Plain permitted to identify and describe the type of soil-formation processes that took part in the development of interstadial and interglacial paleosols. Four paleosol complexes are distinctly identified within the limits of the studied region: Vorona (MIS 13/15), Inzhavino (MIS 8/9 or MIS 10/11), Kamenka (MIS 6/7 or MIS 8/9), Mezin (MIS 5); besides, there are the Bryansk interstadial paleosol (MIS 3) and Rzhaksa interglacial paleosol (MIS 17), both well identifiable in the region. The results obtained are in general agreement with the earlier conclusions by Velichko et al. (2012) about a general reduction of heat and moisture supply and an increase in aridity from the earlier towards later stages of the Pleistocene. The new data revealed, however, a few differences from the earlier concept. To mention but one example, we have found that the Kamenka interglacial (MIS 7 or MIS 9) paleosols formed in environments more humid than those of the Likhvin interglacial (MIS 9 or MIS 11).

An integrated study of the loess–soil sequence in the coastal exposure near the settlement of Beglitsa (Rostov oblast) allowed us, for the first time, to reconstruct the landscape-climatic changes that occurred in the eastern Azov region over the course of the Late Pleistocene. In the south of the periglacial zone, considerable differences between intensity of the loess accumulation in the Early and Late Valdai Cryochrons were revealed. In the Early Valdai Epoch, which corresponds roughly to the end of Marine Isotope Stage (MIS) 5 and MIS 4, loess accumulation occurred after completion of development of the Mezin pedocomplex and before the beginning of the Bryansk stage of soil development, i.e., over more than 20 000 years. In the much shorter Late Valdai Cryochron MIS 2 (10 000–12 000 years), loess accumulation reached 5 m. The data evaluation shows that the loess accumulation rates in the Early Valdai Epoch (~0.07 mm/year) and the Late Valdai Epoch (~0.5 mm/year) differ from each other by an order of magnitude.

Based on the complex studying 10 meter thick loess-soil sequence in the Beglitsa section (47°08° N, 38°31° E), the landscape and climate changes in the north-eastern Azov Sea Region in the Late Pleistocene were reconstructed. The intensity of loess accumulation decreased in the interglacial and interstadial conditions, when the soil-forming processes prevailed, and increased in cryoarid conditions of the glacial epoch, and especially, during the Late Valdai. As indicated by topography of palaeosoil horizons, loess layers of various ages envelope in sequence the primary fluvial (erosional-accumulative) relief. Loess accumulation resulted in general rise of the terrace surface. It preserved the major features of original topography but gradually smoothed the minor ones. During the entire Late Pleistocene the studied area belonged to the steppe zone. Participation of forbs in steppe communities, as well as the grass cover density, decreased in the cryoarid periglacial conditions and increased under warmer and less continental interstadial or interglacial climate. The role of intrazonal tree communities (pine forests with steppe elements, birch and alder wet forests) remained minor even in the most favorable climate of the Mikulino Interglacial, when the broad-leaved trees (mainly Quercus) participated in the forests. During the interstadial warm phases of the Valdai glacial epoch, the trees growing at present in the severe continental climatic conditions (Larix, Pinus sibirica) occurred in the region. As in the present time, near the shore of the Azov Sea, the areas with disturbed soil cover, including those with saline soil, were widespread due to abrasion, development of slumps and landslides, and erosion.

Multi-proxy studies of loess-soil sequences in the eastern Azov Sea region (Beglitsa‑2 section) and the northwestern Loess Plateau of China (Caoxian section) let us to suggest the correlation of the main stratigraphic horizons and to provide the comparison of landscape and climatic changes in these regions during the last interglacial-glacial climatic macrocycle. It was found that the Loess Plateau was characterized by a steady accumulation of loess during both glacial and interglacial epochs, when the so-called “warm” loess was formed. In the NE Sea of Azov region, the main loess accumulation corresponded to cryoarid conditions of the glacial phases, while during the interglacials, loess accumulation became ten times slower. The average sedimentation rate of loess material calculated for Caoxian section was more than 5 times higher than the one calculated for the Beglitsa‑2 section. Late Pleistocene paleosoils in the Beglitsa‑2 section are of the steppe type and correspond to the Salyn (MIS5e), Krutitsa (MIS5c), and Bryansk (MIS3) climate phases. Morphology of the Azov paleosoils is much better expressed than that of the paleosoils at Caoxian, where only the S1SS3 semidesert paleosoil (MIS5e) can be seen directly in the section. Climatic fluctuations in the southern East European Plain within the last interglacial-glacial macrocycle had significantly greater amplitude than that in the north-west of the Loess Plateau. In the latter, cryoarid glacial conditions alternated with warm semiarid interglacial conditions. In the northwestern Loess Plateau, the main climate dynamics was associated with the hydrological regime changes under the influence of the East Asian monsoon activity, which was at its lowest during the glacial stages (drier climatic phases) and increased during the interglacial and interstadials (wetter climatic phases).

The loess-palaeosol deposits at the Beglitsa section in the East European Plain play an important role in the understanding of climate and environmental changes in Eurasia. However, the absence of absolute geochronology has restricted the interpretation of the loess sedimentation process and its relevance to palaeoenvironmental change. In this paper, a detailed chronology was obtained from the Beglitsa section using a quartz optically stimulated luminescence (OSL) dating technique in the southern area of the East European Plain. Grains with a diameter of 38-63 mm extracted from 8 samples and a single-aliquot regenerative-dose (SAR) protocol were applied for equivalent dose (De) determination. The results showed that the OSL ages are generally in agreement with the field-observed stratigraphic order and no age inversions were apparent. Compared with magnetic susceptibility and previously published radiocarbon ages, the OSL dating results showed great potential to provide a reliable chronology sequence for loess sediments in the Sea of Azov. With a span ranging from 5.4 +/- 0.4 to 203.8 +/- 18.0 ka, deposition of the Azov loess may have begun during the penultimate glaciation. Based on a comparative analysis of the stratigraphic composite, the sedimentary thickness differences between sections around the Azov region were likely affected by the local topography and the location. (C) 2017 Elsevier Ltd and INQUA. All rights reserved.

Multi-proxy studies of loess-soil sequences in the eastern Azov Sea region (Beglitsa‑2 section) and the northwestern Loess Plateau of China (Caoxian section) let us to suggest the correlation of the main stratigraphic horizons and to provide the comparison of landscape and climatic changes in these regions during the last interglacial-glacial climatic macrocycle. It was found that the Loess Plateau was characterized by a steady accumulation of loess during both glacial and interglacial epochs, when the so-called “warm” loess was formed. In the NE Sea of Azov region, the main loess accumulation corresponded to cryoarid conditions of the glacial phases, while during the interglacials, loess accumulation became ten times slower. The average sedimentation rate of loess material calculated for Caoxian section was more than 5 times higher than the one calculated for the Beglitsa‑2 section. Late Pleistocene paleosoils in the Beglitsa‑2 section are of the steppe type and correspond to the Salyn (MIS5e), Krutitsa (MIS5c), and Bryansk (MIS3) climate phases. Morphology of the Azov paleosoils is much better expressed than that of the paleosoils at Caoxian, where only the S1SS3 semidesert paleosoil (MIS5e) can be seen directly in the section. Climatic fluctuations in the southern East European Plain within the last interglacial-glacial macrocycle had significantly greater amplitude than that in the north-west of the Loess Plateau. In the latter, cryoarid glacial conditions alternated with warm semiarid interglacial conditions. In the northwestern Loess Plateau, the main climate dynamics was associated with the hydrological regime changes under the influence of the East Asian monsoon activity, which was at its lowest during the glacial stages (drier climatic phases) and increased during the interglacial and interstadials (wetter climatic phases).

In the valley of Imangda river (western part of Putorana Plateau) four multiple-aged moraine complexes were identifi ed. Three of them are correlated with the known stages of deglaciation of the Late Pleistocene glaciation in the north-west of Siberia: karaulskaya stage (25–17 ky BP), nyapanskaya stage (15–13 ky BP) and norilsk stage (11.5–10.4 ky BP). Moraines of these stages vary in degree of preservation, roundness of coarse material and the extent of their areal. In the Late Pleistocene and Holocene the glaciation of this territory had cirque and mountainvalley nature. There was no solid ice cover over the plateau. However, isolated ice caps with outlet glaciers could exist in some parts of the plateau. The fourth, younger moraine was formed during the Little Ice Age. Glaciers then do not go beyond the cirques.