Introduction

Given the incompleteness of the Pleistocene geological record in most of Northern Eurasia, the solution of issues of detailed dissection of recent sediments and correlation of interglacial / glacial horizons, both periodization and comparison of climate-related paleogeographic events, should be based primarily on knowledge of the spatial and temporal patterns of flora, vegetation and climate development established from paleogeographic materials of the stratoregions studied in detail in this territory.

Priority in determining the regularities of changes in the nature of the Earth in the Pleistocene belongs to Academician K. K. Markov (1960). Materials on the history of vegetation cover were among the most important paleogeographic evidence, on the basis of which he concluded that the main patterns of changes in the natural environment are orientation, rhythm and metachronism (local individuality). All subsequent decades of studying these materials by paleogeographers were devoted to the accumulation and synthesis of new analytical data in order to identify the features of the directed development of the natural environment, determine the number of warm and cold rhythms of different ranks within the Pleistocene, as well as the regional specifics of the natural process in various natural history areas.

Currently, fractional climatostratigraphic schemes of the Neo-Pleistocene of the continental regions of Northern Eurasia are based on continuous records of interglacial and glacial landscape-climatic successions reconstructed based on the results of a detailed palynological analysis of the most complete sections of the European subcontinent. Similar palynoclimatostratigraphic records were obtained for sections of southern Western Europe-Boucher/It is found in the south-east of the Central Massif in France (Reille and Beaulieu de, 1995; Reille et al., 1998), Castiglione in Central Italy (Follieri, Magri, Sadori, 1988), and Tenagi Philippon in North-Eastern Greece (Wijmstra, 1969; Hamen, Wijmstra, Zagwijn, 1971; Wijmstra, Smit, 1976; Wijmstra and Groenhart, 1983], Ioannina in Northwestern Greece (Tzedakis, 1993; Tzedakis et al., 2001), as well as sections in the center and south of Eastern Europe - Likhvin on the Upper Oka (Bolikhovskaya, 1974, 1976, 19956), Odintsovo in the Moscow region [Maudina, Pisareva, Velichkevich, 1985], Strelitsa on the upper Don [Bolikhovskaya, 1976, 19956], Otkaznoye on the middle Kuma [Bolikhovskaya, 1995a, b] , etc.

The main problem of periodization and correlation of paleogeographic events and establishment of spatiotemporal regularities in vegetation development at the present stage of research is that stratigraphic constructions are often used in the following cases:

The study was carried out within the framework of the program of the Presidium of the Russian Academy of Sciences "Origin and Evolution of the biosphere" and the RGNF project No. 07-01-00441.

page 2

For the most part, reconstructions of the history of vegetation and climate development are carried out based on the results of palynological analysis of far-flung and fragmentary sections, in which there are deposits of only one interglacial-glacial cycle or, very rarely, several interglacial and glacial rhythms.

This article focuses on a detailed palynological study of the reference sections of various stratoregions, where the latest deposits are most fully represented, characterized by the entire complex of paleogeographic materials, and contain an almost continuous paleogeographic record of the Neo-Pleistocene. Based on the data obtained, the number of warm and cold epochs of the Neo-Pleistocene and their paleoclimatic features are determined, the composition of interglacial and periglacial floras of the East European loess province is revealed, and the vegetation development phases of an almost continuous series of interglacial and glacial epochs of the Neo-Pleistocene are reconstructed in detail. The main stages of vegetation and climate change in various regions of the East European Plain over the last 900 thousand years have been characterized on the basis of their own and other published materials (Bolikhovskaya, 19956, 2004; et al.).

The synthesis of extensive paleogeographic information made significant adjustments to the understanding of the features of the three most important spatial and temporal patterns of flora, vegetation, and climate development-directionality, rhythmicity, and metachronism-and allowed us to draw new conclusions about the directional change in neo-Pleistocene floras and the specifics of zonal differentiation of vegetation cover during interglacial and glacial epochs, as well as to establish another major pattern in the history of the Earth. vegetation and climate of the Neo-Pleistocene-cyclicity and consider its characteristic features.

Methodological issues

Paleontological methods used to reconstruct the history of origin and development, as well as the conditions of existence of the organic world, include an extensive complex of paleobotanical and paleozoological studies of fossils of plants and animals enclosed in the thickness of different-age and different-facies deposits. Fossils of fungi, lichens, bacteria, lower plants (algae), as well as generative (pollen, spores, seeds, fruits, cones) and vegetative (leaves, stems, etc.) organs of higher plants are objects of paleoalgological, palynological, paleocarpological, phytolithic, paleoxylological and other analyses.

Palynological (spore-pollen) analysis, the results of which are presented in this paper, is one of the leading methods for reconstructing terrestrial paleoregivation. Its priority position in paleobotanical methods is due to the fact that the pollen and spores of higher plants studied by palynological analysis are the only group not only in paleobotany, but also in paleontology as a whole, which is present in sediments of all lithological and genetic types. Terrestrial plants produce a huge amount of pollen and spores, the shell (sporoderm) of which, in the overwhelming majority of plants, has exceptional resistance to destructive chemical and physical effects. Microscopic size (mainly 10-100 microns) and morphological features contribute to the spread of pollen and spores (by wind, insects, water, and other agents). on the surface of land and water areas and their burial in loose sediments. Fossil spore-pollen spectra (palynospectra) are a reflection of the paleoregenery of the surrounding area.

Palynological data are most widely used in studying the nature of the last million years. Vegetation responds quickly to climate changes, so palynological data allow us not only to establish all the warm and cold periods of the Pleistocene, but also to reconstruct the continuous sequence of floristic, phytocenotic and climatic changes that occurred during these periods, and to identify the climatic and phytocenotic features of each of them.

The results of paleogeographic interpretations of palynological data are reconstructions of the most important indicators of the main stages of vegetation and climate change - the composition of flora, the zonal type of vegetation cover, the nature of dominant plant formations and their differentiation within the studied territory, successions of phytocenoses during climate rhythms of different ranks, qualitative climate characteristics and quantitative values of the most informative climate parameters (annual temperatures and sums precipitation, temperatures of the warmest and coldest months, the sum of active temperatures above 5°C, etc.).

The palynospectrs of recent sediments serve as a basis for reconstructing the appearance of both zonal (placor, automorphic) paleolandscapes and azonal or intrazonal plant communities.

page 3

communities. Reconstructions of hydromorphic paleolandscapes and justification of the age of subaqueous strata are significantly supplemented by the results of studying pollen grains and spores of coastal and aquatic plants found in their spectra.

Detailed spore-pollen analysis of recent sediments of various origins, obtained during complex stratigraphic-paleogeographic studies of Pleistocene reference sections in various regions of Northern Eurasia, has shown that palynological data are highly informative for reconstructing a continuous sequence of climatic events over the past 900 thousand years (Bolikhovskaya, 19956, 1999; et al.). Reconstructions based on palynological data are highly informative. such characteristics of the Pleistocene history of flora, vegetation, and climate as: 1) the number and rank (interglacial, glacial, inter-stage, etc.) of the main stages of their development; 2) features of succession processes within each warm and cold stage; 3) differentiation of vegetation cover in different areas for different chronological sections climate optima of interglacial periods and pessimums of glacial epochs); 4) dynamics (appearance, migration, disappearance) of individual taxa, floras, vegetation zones, formations, etc. during individual climatic rhythms and the Pleistocene as a whole; 5) the amount of displacement of the boundaries of zones, subzones, and smaller natural-territorial complexes in different segments of the Pleistocene; 6) the composition, time of existence, and geographical location of refugia. As we can see, the palynological method is rightfully one of the leading methods for reconstructing the history of vegetation and climate, as well as climatostratigraphic division and correlation of Pleistocene deposits.

Terms of palinostratigraphy and climatostratigraphy

"Palynozone (zone)", " sub-palinozone (or subzone)", "phase", "subphase", "stage", "rhythm", "cycle" are terms that are commonly used in palynostratigraphic studies of Pleistocene deposits. Some of them - "rhythm", "cycle" and "phase" - along with the terms "rhythm", "cyclicity", "stage", "phasing", etc. They are among the main terms of climatostratigraphy and periodization of paleoclimatic events.

As the analysis of works devoted to the regularities of the development of paleoclimates and paleolandscapes shows, researchers often understand the same term differently or use the same content in different terms (Zubakov, 1968, 1986, 1992; Starkel, 1977; Izmeni..., 1980; Velichko, 1981, 1987; Veklich, 1982, 1990]. Most often, both domestic and foreign publications use the words "rhythm" and "cycle" as synonyms; they denote a time interval (period) that includes one warming and one cooling of different ranks. Taking into account the time covered by climatostratigraphic divisions, classifications of climatostratigraphic taxa have been developed. For example, A. A. Velichko [1987, 1999] divides cycles into mega-, macro-, meso-, micro -, and nanocycles in the history of the Earth's landscape envelope, depending on the duration of cycles. When summarizing the results of an in-depth and comprehensive study of the evolution of the natural environment of Northern Eurasia, he calls the Mesozoic-Cenozoic cycle a megacycle, and each pair of interglacial and glacial epochs of the Late Cenozoic a macrocycle.

Taking into account the disagreements of paleogeographers on the content of the terms "cycle" and "rhythm", we will indicate the meaning in which they are used by us (Bolikhovskaya, 1988, 1990a, 1995b). The word "cycle" (from Greek. "kyklos" - circle) means a set of processes with a complete circle of development. Therefore, we, like many researchers, use this term to refer to time intervals that are characterized by completed natural processes and are periodically repeated. Cycles are periods from the beginning of one interglacial epoch to the beginning of another. Cycles, according to our data, are also two longer 450-thousand-year intervals of the Neo-Pleistocene. Each of these intervals, including the alternation of four pairs of interglacial and glacial epochs, is characterized by individual features of climate-phytocenotic changes and the completeness of the process of these changes. Cyclicity - change, repeatability of cycles.

As the analysis of specialized dictionaries and encyclopedias has shown, the word "rhythm", unlike the term" cycle", does not have terminological clarity. Rhythm (from Greek. "rheo" - flow, "rhythmos" - alternation) - a form of flow in time of any (any) alternating processes. Since rhythmicity is based on the division into two parts, rhythms, in our opinion, are more logical to call consecutive fluctuations (in the direction of heat or cold, humidity or dryness), each of which contains an ascending and descending phase or a group of ascending and a group of descending phases. As follows from the results of a detailed palynological analysis, the warm and cold intervals of the Pleistocene with different ranks have a specific climatic rhythm peculiar to each of them. Every interglacial

page 4

an epoch is distinguished by its characteristic interglacial climate rhythm, and each ice age is distinguished by its inherent glacial climate rhythm.

Thus, the Pleistocene climate cycles consist of a single pair or group of pairs of interglacial and glacial climate rhythms. For example, the Late Pleistocene cycle contains the Mikulinsky interglacial and Valdai glacial rhythms.

The traditional palynostratigraphic terms listed at the beginning of this section are used by the author mainly in the meanings formulated in the classical works of V. P. Grichuk [1950, 1960, 1961, 1989; et al.; Grichuk V. P., Zaklovskaya, 1948; Grichuk M. P., Grichuk V. P., 1960], who laid the foundation for our work. The basic principles of stratigraphic, paleogeographic, and paleoclimatic interpretation of the results of palynological analysis of Cenozoic deposits are presented.

Each interglacial and glacial epoch and, accordingly, each corresponding climate rhythm consists of two stages. The glacial climate rhythm includes cryohygrotic and cryoxerotic stages, within which periods of glaciation or cooling proper are distinguished, i.e. stadials, and warming between them - interstadials. The interglacial rhythm includes thermoxerotic and thermohygrotic stages.

In addition, as shown by the materials of our detailed palynological studies of the most complete sections of the Neo-Pleistocene, interglacial rhythms contain one or more intraglacial cooling events. We propose to call relatively short-term intervals of intraglacial cooling that separate the thermal maxima of interglacial periods endothermal cooling (Bolikhovskaya, 19906, 1991). Endothermal cooling events with varying degrees of severity on the palynological diagrams were established in the sections studied for most of the nine reconstructed interglacials of the Neo-Pleistocene (Bolikhovskaya, 19956). Most often, their florophytocenotic characteristics are close to regional interstadials. An important paleogeographic and stratigraphic feature is the stable presence of endotherms between the thermoxerotic and thermohygrotic stages of interglacial rhythms.

Cryohygrotic and cryoxerotic or, respectively, thermoxerotic and thermohygrotic substages can often be distinguished within stadials, inter-stadials, stages of climatic rhythms, and endotherms.

The most fractional climatostratigraphic units of palynology are phases and subphases that characterize the zonal and formational features of reconstructed paleophytocenoses. They correspond to the palynozones and sub-palynozones identified on the spore-pollen diagrams, which represent one or a group of palynospectroses that differ from others in the composition and percentage of pollen and spores.

Features of rhythmic development of vegetation and climate

K. K. Markov (1978) emphasized that the most important regularity of nature change is its directed development. The results of studies of the evolution of the natural environment of the Pleistocene convince us that it is impossible to establish the features of the directed development of vegetation and climate without a detailed reconstruction of the climatorrhythmics of this period.

To date, an extensive analytical material has been accumulated; it has formed the basis for the periodization schemes of interglacial and glacial events that reflect the global climatic rhythm of the Pleistocene. However, according to the analysis of inter-regional and regional stratigraphic schemes of the East European Plain (Alekseev et al., 1997; Shik, Borisov, and Zarrina, 2002), conclusions about the number, taxonomic rank, and chronology of warm and cold epochs that have followed each other over the past approximately 900 thousand years are still contradictory. In the maps of different regions for the Neo-Pleistocene, from 10 to 20 divisions of interglacial and glacial ranks are indicated. This is primarily due to the incompleteness of the geological record and insufficient study of a number of regions. For example, in the northern part of the glacial region, these causes are associated with both glacial exaration, erosion and partly deflationary processes, and with the inaccessibility of Early and Middle Pleistocene deposits, most often preserved only under the strata of younger sediments in deep exaration hollows, ancient valleys and basins. An important reason for the variety of estimates of the number and rank of thermochrons and cryochrons is the lack of knowledge of Late Cenozoic sections using all the necessary methods. Thus, there are still no representative palynological characteristics for the vast majority of loess and paleosoil horizons, which are proposed as stratotypes of climatostratigraphic units of the Neo-Pleistocene in the loess-soil series of various regions of Eurasia - Eastern Europe [Velichko, Pisareva, Faustova, 2005], Western Siberia [Zykina, 2006], and Central Asia [Dodonov, 2002], etc. This is the position

page 5

This is due to the extreme complexity of obtaining representative paleobotanical materials for subaerial deposits.

K. K. Markov (1938, 1939) considered full-fledged proofs of the independence of glacial epochs on the plains only those data that clearly indicate that the distinguished glacial sedimentation and its correlated periglacial deposits are directly separated in a single section by interglacial sediments that contain plant and/or animal fossils indicating climatic conditions similar to those of the previous century. modern or milder than the climatic conditions of the area under study.

Terrestrial vegetation reacts quickly to climate changes and produces a large amount of pollen and spores in any climatic period. Therefore, only palynological data allow us to establish all the warm and cold stages of the Pleistocene, reconstruct the continuous sequence of changes in flora, vegetation and climate within various stages, and identify the climatic and phytocenotic features of each of them.

We selected reference sections of the most characteristic glacial-periglacial and extraglacial regions of the East European Plain, which differ from each other in the structure of recent deposits and the history of paleogeographic development, as objects for obtaining the results of detailed palynological analysis and reconstructing the continuous paleogeographic record of the Pleistocene on their basis. Located within the development of the maximum (Don, Oka, and Dnieper) cover glaciations and in the extraglacial zone, they contain the most important paleogeographic benchmarks: moraines of these glaciations and their correlated loess horizons, stratotypic (Likhvinsky, Chekalinsky, etc.) interglacial horizons, etc. Chronostratigraphic data on small mammal faunas and the position of the Matuyama-Brunes paleomagnetic inversion dating from about 783 Ka BP were obtained for them.

Generalization of the results of a detailed palynological analysis and multidisciplinary paleogeographic study of reference sections of recent sediments of the North-Central Russian, Desna-Dnieper, Oka-Don, Dniester-Prut, North Azov, East Ciscaucasian and other Eastern European regions made it possible to use an extensive set of historical, floristic and paleophytocenotic criteria for their fractional climatostratigraphic division and age determination interglacial and periglacial palynoflora contained in them. Successional phases in vegetation development of an almost continuous series of global climatic rhythms of different ranks were reconstructed (Bolikhovskaya, 19956).

The totality of paleogeographic data indicates that in Eastern Europe in the Neo-Pleistocene there was a much more complex interglacial-glacial climatorrhythmics than previously thought. We have established the following features of the rhythmic development of nature in the Neo Pleistocene:

I. Changes in the natural environment of the East European Plain during the Neo-Pleistocene were caused by changes in 17 global climate events - nine interglacials and eight glaciations or glacial-grade cooling events separating them (Figure 1). They are reconstructed in the form of complete climatic rhythms of the glacial and interglacial ranks or in the form of a large part of their constituent climatophytocenotic phases. Within the Brunes chron, i.e. in the last approximately 780 thousand years, there were consecutive changes of eight interglacial and seven cold stages separating them.

The development of cover glaciation on the Russian Plain was proved by modern data not only during the Valdai, Dnieper, Oka, and Don stages, but also during the Devitsky cold snap (Setun moraine of the Moscow region), as well as one of the post-Tikhvin (Kaluga, Zhizdrinsky) cold snaps (Vologda and Pechora moraines) [Shik, 1993, 2005].

II. Due to the results of a detailed palynological study of the most complete sections of the Neo-Pleistocene, the climatic rhythms of the glacial and interglacial ranks are subdivided into more fractional climatostratigraphic units:

1. In glacial climatic rhythms, cryohygrotic and cryoxerotic stages, stadials, interstadials, and interphases are distinguished. According to palynological data, each glacial climate rhythm was divided into two stages - cryohygrotic and cryoxerotic, within which cold intervals (stadials) and relative climate warming (interstadials and interphases) varied in severity of climate and duration.

The most complex climatorrhythmics were reconstructed for four glacial stages - the Don, Kaluga, Dnieper, and Valdai. In the formations of the Don and Kaluga glacial stages, one interstadial was reconstructed each. Three inter-stages are established for the Dnieper ice age. In the middle inter-stage, this glacial rhythm was divided into two (Dnieper and Moscow) stages, within which the Early Dnieper and Late Moscow inter-stages were identified-

page 6

1. Scheme of periodization of interglacial and glacial stages of the Neo-Pleistocene of the extraglacial and glacial-periglacial zones of the East European Plain (according to [Bolikhovskaya, 1995b]).

2). Data on the age and natural conditions of the oldest interstadials are very scarce, so we will focus on the characteristics of the Dnieper warming events.

A. N. Molodkov and the author performed a correlation of climatic fluctuations in the last 200 thousand years, reconstructed from palynological materials of Pleistocene sections and EPR-chronostratigraphy data of marine sediments of Northern Eurasia. These studies made it possible to clarify the absolute age of three warming events recorded by the Likhva section's palynostratigraphic record during the Dnieper Ice Age, which dates from approximately 200 to 145-140 Ka BP and corresponds to most of the sixth oxygen isotope stage (X6) [Molodkov and Bolikhovskaya, 2006; Bolikhovskaya and Molodkov, 2005]. According to the palynospectram of water-glacial sediments of the Likhva section, during the early Dnieper inter-stage warming, which led to the melting of ice of the Dnieper glaciation, the upper Oka valley was dominated by periglacial pine woodlands. Judging by the EPR age determinations of mollusk shells taken from the uplifted sea horizons of Severnaya Zemlya, the date of this warming is approximately 184 thousand years ago.

page 7

2. Vegetation and climate successions of the last 235 thousand years, reconstructed based on the results of a detailed palynological study of deposits from the Arapovichi and Likhvin sections/Chekalin.

1-glaciation; periglacial vegetation types: 2-tundra; 3-forest-tundra; 4-steppe; 5 - forest-steppe with areas of coniferous and birch forests; 5a-forest-steppe with broad-leaved trees in coniferous and birch forests; 6-forests; interglacial vegetation types: 7-coniferous forests; 8-coniferous and small-leaved forests with an admixture of broad-leaved species; 9-coniferous and birch-broad-leaved forests; 10 - broad-leaved forests; 11-coniferous-broad-leaved and broad-leaved forests with Neogene relics.

pine woodlands and erik shrub communities of alder Alnaster fruticosus and dwarf birch. EPR data from marine sediments of high-latitude regions of the Eurasian North indicate that the second interstadial warming occurred approximately 172 KA BP. The third (Late Moscow) interstadial warming was characterized on the Upper Oka by the development of periglacial birch woodlands with Betula fruticosa in the shrub layer and a grass-shrub cover, which included cryophytes and xerophytes (Arctous alpina,Arctous alpina, Arctous alpina, Arctous alpina, Arctous alpina, Arctous alpina, Arctous alpina, Arctous alpina, Arctous alpina, Arctous alpina, Arctous alpina, Arctous alpina, Arctous alpina, Arctous alpina, Arctous alpina, Arctous alpina, Arctous alpina, Arctous alpina, Arctous alpina, Arctous alpina, Arctous alpina, Arctous alpina, Arctous alpina, Arctous alpina). cannabis sp.,

page 8

Artemisia subgenus Seriphidium, basil Thalictrum cf. alpinum, etc.). Based on the EPR age determinations of mollusk shells taken from marine sediments of the Taimyr Peninsula, A. N. Molodkov estimates the age of the third interstadial of the Dnieper time to be approximately 155 thousand years.

Ten cold (stadial) intervals, nine interstadials, and several interphases were reconstructed in the Valdai glacial climate rhythm (approximately 70-10 Ka BP, ICS 4 - 2) (Bolikhovskaya, 1986; Bolikhovskaya, 19956). All of them are distinguished by their distinctive floristic, phyto-coenotic, and climatic characteristics, which we and other researchers have described in detail (see Bolikhovskaya, Gunova, and Sobolev, 2001). Landscape and climatic conditions that were somewhat close to interglacial ones were reconstructed for the time of the Ketros (first Early Valdai) interstadial in the Middle Desna (Fig. 2), as well as the Kishlyansk (second Early Valdai) and Dniester (third Middle Valdai) interstadials in the middle Dniester. Based on the materials of palynological studies of the Late Pleistocene loess-soil section Arapovichi, located in the Middle Desna Valley, two Early Valdai, three Middle Valdai interstadial stages and five cold stadial stages were reconstructed within the Valdai pleniglacial. In the Late Valdai interval, one interstadial, three interphases, and five cold stadial stages are distinguished. From the second Early Valdai cold snap to the beginning of the Holocene, the central regions of the Russian Plain were occupied by various types of periglacial landscapes. According to EPR studies of marine sediments, six interstadials with ages of about 65, 56, 44, 32, 26, and 17 Ka were also identified within the Valdai climate rhythm (Molodkov and Bolikhovskaya, 2006).

2. The obtained palynological records reflect significant climate fluctuations during all reconstructed interglacial epochs of the Neo-Pleistocene. In interglacial climatic rhythms, endothermal cooling, thermoxerotic and thermohygrotic stages are clearly recorded. Please explain here that the names of the stages of interglacial (or glacial) climate rhythms are not actually a characteristic of their climate. For example, the term " interglacial thermoxerotic stage "does not always mean that the climate of the study area during this period was warm and dry, and the phrase" thermohygrotic stage " does not always mean a warm and humid climate. These terms (as well as the terms "cryohygrotic" and "cryoxerotic" stages) do not define a specific climate situation, but an important pattern in climate change during each interglacial (or glacial) Pleistocene - the heterogeneity of climatic conditions within rhythms, expressed primarily by their division into two stages. This pattern was first established by M. P. Grichuk and V. P. Based on the results of the analysis of paleobotanical materials on interglacial and glacial deposits of a number of thermochrons and cryochrons in Europe, Western Siberia, and the Far East, and confirmed by our data for all reconstructed interglacial and glacial rhythms.

Let us consider the features of the stages of interglacial climatic rhythms. In all cases, regardless of what zonal types or formations (forest, forest - steppe, steppe, etc.) represented successions of interglacial vegetation, the following regularity can be traced: the first - thermoxerotic - stage of each interglacial rhythm was characterized by changes in phytocenoses that required less moisture supply than the phytocenoses of the second - thermohygrotic-stage of the same interglacial period.

Climatophytocenotic features of both stages of interglacial climatic rhythms were determined by the geographical location and history of paleogeographic development of the studied area, the age of the analyzed interglacial period, etc. Therefore, the same interglacial epoch could be characterized in one region by successions of only broad-leaved forest, in another - forest-steppe and broad-leaved forest, and in the third - steppe and forest-steppe vegetation. Accordingly, the climate of the thermoxerotic stage in one area could be significantly wetter than the climate of the thermohygrotic stage in another area. Another example: in the same stratoregion, the vegetation development period of the Likhva interglacial was characterized only by successions of steppe coenoses, while the preceding Muchkap Interglacial was characterized by successions of moisture-loving broad-leaved forest communities. As we can see, the thermohygrotic stage of one completely steppe interglacial corresponded to a drier climate than the thermoxerotic stage of the other interglacial, during which moisture-loving forests always dominated. However, in all cases, the thermoxerotic stage of each interglacial period was represented by vegetation that required less moisture than the vegetation of the thermohygrotic stage of the same interglacial period. If we analyze the changes of periglacial phytocenoses during complete glacial rhythms, we will see that vegetation of the first (cryohygrotic) stage is always characterized by a large temperature distribution.

page 9

water availability is higher than for vegetation of the second (cryoxerotic) stage.

Let us take a closer look at the most important feature of interglacial climatorrhythmics - intraglacial cold snaps, called endothermal cold snaps (Bolikhovskaya, 1990b, 1991). Endothermal cooling events of varying degrees of expressiveness were reflected in the palynospectra of most interglacials, which we characterized from sections in the central and southern parts of the East European Plain. Depending on the climatic features of various interglacial periods and the zonal affiliation of phytocenotic shifts that occurred during interglacial epochs, these intervals are characterized by a reduction in the participation or complete disappearance of thermophilic plants in the vegetation cover. Intraglacial cooling events are most clearly expressed in the curves of the total pollen content of broad-leaved species and other heat-loving plants presented on palynological diagrams, as well as on the graphs of climatic and phytocenotic successions (Figs. 2, 3).

According to our data, the endotherms that separated the thermoxerotic and thermohygrotic stages of interglacial rhythms had the Gremyachyevskoe, Muchkapskoe, Likhvinskoe s.str. chekalinskoe, Cherepet'skoe, and mikulinskoe interglacials. In the course of vegetation changes in the Mikulinsky interglacial rhythm reconstructed from the Arapovichi section, two endotherms are clearly recorded: one also between the stages of the climatic rhythm, and the other - in the first half of the interglacial period (see Figure 2). The curve of the sum of thermophilic taxa of the Likhva interglacial period-

3. Vegetation and climate successions of the last 660 thousand years, reconstructed from the results of a detailed palynological study of deposits from the Arapovichi and Likhvin sections/Chekalin. 1-glaciation; periglacial vegetation types: 2-tundra; 3-forest-tundra; 4-steppe; 5 - forest-steppe with areas of coniferous and birch forests; 5.5-forest-steppe with broad-leaved trees in coniferous and birch forests; 6-forest; 7-taiga; 8-coniferous and small-leaved forests with admixture deciduous forests; 9-coniferous and birch-deciduous forests; 10 - deciduous forests; 11-coniferous-deciduous and deciduous forests with Neogene relics.

page 10

The Late Middle Ages, which we have described in detail in the stratotypic Likhva section, allows us to conclude that four endothermal cooling events occurred during this longest Neo-Pleistocene thermochron (see the Tt curve in Figure 3).

Researchers are not unanimous in their assessment of the existence of intraglacial cooling events, so we will touch on this issue in more detail. The incompleteness of the geological record and insufficient detail of palynological records often do not allow us to recreate in detail the climatic fluctuations that occurred during the interglacial and glacial periods of the Pleistocene; publications mainly describe flora, vegetation and climate only for the time of the climatic optimum of the studied interglacials or the pessimum of glaciations. At the same time, reconstructions of the paleogeographic conditions of the modern interglacial epoch performed by many researchers for various regions of Northern Eurasia indicate a complex course of climate change, reflecting not only thermal maxima (the so-called boreal, Atlantic, and subboreal optima), but also repeated cold snaps during the Holocene. We obtained detailed data on thermal maxima and cooling events over the last 10 thousand years for the lower Volga region (Bolikhovskaya, 1990a).

Cold snaps during the Pleistocene interglacials are much less frequently detected by analysts, although the duration of the latter is estimated to be significantly longer than the Holocene (Bowen et al., 1986). For the first time, the conclusion about the intraglacial cooling of the last interglacial period was reached by Jessen and Milthers (1928), N. A. Makhnach (1971), and other researchers based on the results of spore-pollen analysis of the Eemian (Mikulinsky, Muravinsky) lake-swamp sequences. In our opinion, this cooling is clearly illustrated by diagrams of fairly complete Eemian sections of Europe, for example, diagrams of the Pryalitsa (Sanko et al., 1989), Kozya (Elovicheva, 1981), and Dolgoye (Loginova, Makhnach, and Shalaboda, 1989) sections in Belarus, and Vyatskoye on the Upper Volga (Valueva and Serebryany, 1978) sections where the endothermal is fixed at the boundary of the palynozone M46 and M5 + 6, as well as the Hollerup section in Jutland (Jessen and Milthers, 1928) and Zeifen section in Bavaria, where the endothermal shows zone 7 (Jung, Beug, and Dehm, 1972).

When studying the Late Pleistocene loess-soil sequence of the Molodov I Mousterian site on the middle Dniester, we also established two thermal maxima for the Mikulinsky interglacial rhythm, separated by a significant intraglacial cooling (Bolikhovskaya, 1982). Detailed palynological records of the Arapovichi section on the middle Desna made it possible to establish the presence of another, earlier intramiculine cooling (Bolikhovskaya, 1993). According to the new interpretation of these data (see above), the cooling observed in the Likhva interglacial period based on the results of the analysis of stratotypic deposits of the Chekalinsky (Likhva) section (Bolikhovskaya and Boyarskaya, 1982) is supplemented by three more intraglacial cooling events. Significant palynological data on interglacial endotherms were obtained for the western regions of the Russian Plain. According to Ya. K. According to Elovicheva (1992), one optimum corresponded only to the Holocene, Smolenskaya, and Korchevsky interglacials of Belarus, while the Muravinsky (Mikulinsky), Belovezhsky, Alexandriysky (Likhvinsky), and Ishkold interglacials had two optima each, and the Shklovsky interglacials had three optima separated by intraglacial cooling.

It should be noted that data on intraglacial cooling is very important both for solving the issues of detailed stratigraphy and correlation of paleoclimatic events of the Pleistocene, and for creating predictive models of changes in the natural environment in the future.

Cyclicity in the development of vegetation and climate in the Neo-Pleistocene

Cyclicity is another major pattern in the development of vegetation and climate. As mentioned in the section on the terms of palynoclimatostratigraphy, cycles refer to periods with completed natural processes. According to reconstructions based on the results of palynological studies, two types of cycles in the development of vegetation and climate of the Neo-Pleistocene are most clearly expressed, differing in duration and structure. In addition to the cycles, each of which characterizes changes in flora and vegetation during one interglacial and one glacial epoch, significantly longer cycles were traced, covering four interglacial/glacial pairs (Bolikhovskaya, 2005). This cyclicity in the development of vegetation and climate of the Neo-Pleistocene was revealed by a comparative analysis of flora and climate-phytocenotic successions reconstructed for the last million years based on the results of studying the Otkaznoye section, which is unique in its geological completeness (Fig. 4) (Bolikhovskaya, 19956).

The Otkaznoye section (44°20' N, 43°50' E) is located in the middle reaches of the Kuma River within the present-day-

page 11

4. Climatostratigraphic division of the Otkaznoye section sediments. Reconstructions of vegetation and climate changes in the Eastern Ciscaucasia in the Pleistocene (based on palynological data). Periglacial vegetation types: 1-semi-deserts and dry steppes; 2-steppes; 3-forest-steppes; 4-birch and coniferous-birch woodlands; extraglacial vegetation types: 5-forest-steppes; 6-birch woodlands; 7-spruce and cedar-spruce forests; 8-birch woodlands with an admixture of broad-leaved species; 9-birch forests with mixed with broad-leaved species; 10-coniferous-birch and birch-coniferous forests mixed with broad-leaved species; 11-forest-steppes; 12-steppes; 13-foothill forest-steppes; 14-hornbeam forests; 15-elm-oak, oak, hornbeam-oak forests; 16-hornbeam forests; 17-oligo - and polydominant broad-leaved forests; 18-polydominant broad-leaved forests with subtropical elements.

grass-fed tipchak-feather grass steppes. It characterizes the Eastern Ciscaucasian region - one of the most remote loess regions from the zone of cover glaciation. Here are the most powerful loess-soil profiles of the European subcontinent. A comprehensive study of the thickness of Eopleistocene-and Neo-Pleistocene deposits (thickness approx. 140 m) was carried out by us together with A. A. Velichko, E. I. Virina, A. K. Markova, D. R. Morozov, T. D. Morozova, V. P. Udartsev, S. S. Faustov and others. Its stratigraphic division is based on palynological, microtheriological, and paleomagnetic data. Changes in flora and landscape and climatic conditions during the Brunes chrono are reconstructed with the greatest detail. The floristic, phytocenotic, and climatic successions of interglacial and glacial rhythms of the Neo-Pleistocene are analyzed in detail in a number of publications (Bolikhovskaya, 1995b, 1997, 2004).

A detailed comparative analysis of the reconstructed floristic, phytocenotic, and climatic successions has established that each of the interglacial and glacial rhythms in the interval from the Pokrovsky cooling to the Likhva Interglacial (inclusive) has its younger counterpart, i.e., the epoch in the interval from the Kaluga cooling to the Holocene interglacial (inclusive), which is close in terms of the most important paleogeographic indicators. The analogy can be traced in the similarity (or proximity) of the zonal affiliation of the dominant vegetation, the degree of aridization or humidization of the climate (in comparison with other warm and cold epochs of "its" interval), the scale of development of ice sheets of correlated cryochrons, etc.

The Likhva interglacial period, which is compared with the 11th marine isotope stage (MIS 11), clearly parallels the modern interglacial epoch (MIS 1), since only the Likhva interglacial period in the Middle Kuma recorded a typical steppe phase, during which grass steppes dominated - a characteristic component of the Holocene landscapes of this territory. The accumulation of only Likhva deposits, as well as Holocene deposits of Otkazny, occurred during the period of dominance of open forest-steppe and steppe landscapes. The logical difference between the Likhva Interglacial period and the Holocene period is the presence of the Likhva thermochron in limited developed forest areas and in the typical taxa of the Likhva dendroflora of the Rejection Picea sect. Omorica, Pinus sect. Strobus, Betula sect. Costatae, Juglans regia, Ostrya sp. etc.

The conclusion that the paleogeographic analog of the Holocene is the Likhva thermochron corresponding to MIS 11 is in good agreement with the paleogeographic data obtained in recent years for other regions and natural objects. Researchers note the similarity of the orbital configuration, global climate and regional climate regimes, and other paleogeographic parameters of the two warm epochs corresponding to MIS 11 and MIS 1 (Bauch et al., 2000; Hodell, Charles, and Ninnemann, 2000; McManus, 2004).

page 12

5. Chronology and correlation of the main paleoclimatic events of the last 600 thousand years reconstructed from palynological data in the glacial-periglacial and extraglacial zones of the East European Plain with paleoclimatic events identified and dated from EPR data in the paleoshelf zone of Northern Eurasia (according to [Bolikhovskaya and Molodkov, 1999; Molodkov and Bolikhovskaya, 2002]).

page 13

Based on the totality of paleogeographic characteristics, it is established that the Oka glacial stage (MIS 14-12), during which periglacial forest - steppes dominated in the Eastern Ciscaucasia, is a paleogeographic analog of the Valdai glaciation (MIS 4-2), which was characterized by the dominance of periglacial forest - steppes and semi-deserts.

During the Muchkap thermochron, Srednyaya Kuma was dominated by broad-leaved forests with subtropical species, and most of Eastern Europe was occupied by a forest zone, which was dominated by forests with Neogene relics during the Interglacial optima. We consider the paleogeographic analog of the Muchkap Interglacial (MIS 15) to be the Mikulinsky Interglacial (MIS 5), during which broad-leaved forests were also developed in the study area, but without subtropical species. Like the Muchkap Interglacial period, the Mikulinsky period was a stage of predominant development of forest landscapes on the territory of the East European Plain (Bolikhovskaya, 2004).

The paleogeographic analog of the Don glaciation (MIS 16), which was characterized by the maximum development of the ice cover in the Pleistocene, is the Dnieper glaciation (MIS 6), which is slightly inferior to the first one in terms of the area of the ice sheet. In the Don period, periglacial coniferous-birch woodlands with yernik communities prevailed on the Srednyaya Kuma River. During the Dnieper glaciation, at first periglacial sparsely populated woodlands dominated here, and then, under conditions of increased continental climate, they were replaced by periglacial semi-deserts.

The young analog of the Semiluk Interglacial (MIS 17) is the Cherepet thermochron (MIS 7). In the Semiluk period, Srednyaya Kuma was dominated by forest-steppes with areas of broad-leaved forests - hornbeam, oak-hornbeam, linden-hornbeam, ash-maple-hornbeam, and birch. The characteristic taxa included Picea sect. Omorica, Pinus subgenus Haploxylon, Betula sect. Costatae, Carpinus betulus, C. orientalis, Quercus cf. ilex, Tilia cordata, T. tomentosa, Fraxinus sp., Acer sp. The vegetation cover of the Cherepet Interglacial was similar in natural and zonal terms to that of the Semiluk Interglacial: sparse woodlands and xerophytic shrub coenoses of the thermophilic series dominated: hornbeam, oak, oak - hazel, birch and other park forests, in which Betula raddeana, Carpinus betulus, C. orientalis, Ostrya sp., Corylus colurna, Quercus robur, Q. pubescens, Q. ilex, Q. petraea, Tilia cordata, T. platyphyllos, T. tomentosa.

An analog of the Devitsky cold snap (MIS 18) is the Zhizdrinsky cold stage (MIS 8). Periglacial landscapes of the Devitsky cold snap were characterized by a predominance of birch woodlands. The Zhizdrinsky cryochron was characterized by more cryoarid conditions and predominance of shrubby alder-erik communities along with periglacial birch woodlands.

The dominant vegetation types of the Gremyachyevsky thermochron (MIS 19), which was a paleogeographic analogue of the Chekalinsky interglacial (MIS 9), were broad-leaved forests and forest-steppes. Among the forest successions of the Gremyachyevsky Interglacial period are birch forests, hornbeam forests, birch-oak, hornbeam, oak-lime-hornbeam, walnut-beech-hornbeam, oak-elm groups. Characteristic taxa of gremyachyevskaya Otkazny flora-Cedrus sp., Picea sect. Omorica, Betula sect. Costatae, Fagus orientalis, Quercus robur, Q. castaneifolia, Q. ilex, Carpinus caucasica, C. betulus, C. orientalis, Ostrya sp., Corylus colurna, Tilia platyphyllos, T. tomentosa, T. cordata, Morus sp. etc. Succession processes that dominated during the Chekala interglacial in broad-leaved forests are recorded by phytocenotic phases with a predominance of similar groups (linden-elm-hornbeam-oak, hazel-oak, linden-elm-hornbeam-oak, oak-hornbeam, alder and birch). Among their characteristic taxa, a group of such thermophilic elements of dendroflora as Fagus orientalis, Carpinus caucasica, C. betulus, and Ostrya cf was distinguished. carpinifolia, Corylus colurna, Acer sp., Quercus robur, Q. petraea, Q. ilex, Q. pubescens, Tilia platyphyllos, T. tomentosa, T. cordata, Ulmus laevis, U. scabra, U. campestris, Morus sp. etc.

The Pokrovskoe Ice Age (MIS 20), for which the development of periglacial steppes was reconstructed, is a paleogeographic analog of the Kaluga cryochron (MIS 10). The landscape and climatic peculiarity of the Kaluga cold period consisted in the fact that during its cryohygrotic maximum, the existence of periglacial forest-steppes that also dominated in the study area was interrupted by the expansion of spruce and cedar-spruce forests.

The comparisons made indicate a regular cyclical nature of changes in the natural environment in the Neo-Pleistocene. Each cycle spans four interglacial and four glacial epochs. All interglacials of the younger Kaluga cooling-Holocene cycle are characterized by a more continental climate and significantly lower participation of Neogene relics and plants alien to modern flora in the vegetation cover than their interglacial counterparts of the Pokrovskoe cooling - Likhva interglacial cycle.

page 14

Paleogeographic publications contain data on climate cycles of different durations. In the works of geophysicists, mathematicians, and paleoclimatologists, the dependence of climatic fluctuations on astronomical cycles is most often considered - fluctuations in the inclination of the ecliptic to the equator, the eccentricity, and the longitude of the perihelion of the Earth's orbit (Izmeneniya..., 1980). The fundamental hypothesis of M. Milankovich [1939] is recognized, according to which the change in the eccentricity of the Earth's orbit corresponds to a cycle of 90-100 thousand years, the duration of the cycle of secular fluctuations in the inclination of the ecliptic to the equator is approx. 40 thousand years, and the cycle of perihelion longitude fluctuations is approximately 21 thousand years. When analyzing climate fluctuations and the duration of climate cycles caused by solar radiation and the Earth's orbital parameters, Sh. G. Sharaf [1974] established the periodicity of 41 and 200 thousand years of fluctuations in annual insolation at all latitudes of the Earth. In the lower latitudes, under the influence of eccentricity and perihelion longitude, summer insolation varies mainly with a period of 21 thousand years, the amplitude of fluctuations varies with a periodicity of 100, 425, and 1200-1300 thousand years. In the middle latitudes of the Earth, fluctuations in summer insolation have a periodicity of 21 and 41 thousand years, and the magnitude of the amplitude of fluctuations, mainly due to eccentricity, is 100 and 425 thousand years.

What is the time scope of the two long cycles of vegetation and climate development that we have identified during the Neo-Pleistocene? To determine the age and duration of the reconstructed warm and cold stages of the Neo-Pleistocene, the author and A. N. Molodkov (Molikhovskaya and Molodkov, 1999; Molodkov and Bolikhovskaya, 2002, 2006) compared continental sediments and paleoclimatic events of the extraglacial and glacial-periglacial zones of the East European Plain with warm climatic rhythms reconstructed on the basis of EPR- analysis of shells of marine subfossilized mollusks from transgressive sediments of sections of the paleoshelf zone of Northern Eurasia and with the oxygen isotope scale of oceanic sediments (Bassinot et al., 1994) (Fig. 5).

The obtained data on the age and duration of interglacial and glacial climate rhythms of the Neo-Pleistocene are shown in Table 1. A comparison of the revealed cyclical changes in vegetation and climate over the last million years with data on the age and duration of interglacial and glacial climate rhythms indicates that the duration of cycles in the development of the natural environment of the Neo-Pleistocene was approximately 450 thousand years (Fig. This is the duration of the cycle "Pokrovskoe cooling - Likhvinskoe interglacial" (see Figure 6, Table 1). Taking into account the correlation studies, we can conclude that the Holocene, like its counterpart - Likhvinskoe interglacial, will be just as long and the duration of the cycle "Kaluga cooling - Holocene interglacial" will also be approximately 450 thousand years. years.

Thus, the detailed characterization of vegetation and climate development during the Likhva Interglacial period should be considered as an analog model of their changes in the previous and future stages of the modern interglacial epoch.

The Likhvinsky interglacial period in the Otkaznoye section corresponds to the formation of the soil complex (PC) IV (more than 3 m thick), consisting of three fully developed fossil soils. According to palynological data, changes in the vegetation cover in the middle Kuma region were expressed by rearrangements in the structure of steppe coenoses and broad-leaved and mixed forests. This is evidenced by six reconstructed phases in vegetation development (palynozones L1-L6): L1-forest-steppes with the dominance of mixed grass-grass steppes and the participation of birch and coniferous-birch forests; L2-grass steppes with areas of walnut-oak forests from Juglans regia and Quercus robur; L3 - forest-steppes with beech-hornbeam and coniferous forests.- birch forests; L4, L5-forest-steppes of endothermal cooling, represented by grass steppes, birch forests and hornbeams from Carpinus orientalis; L6-forest-steppes dominated by mixed grass-grass communities and walnut-hornbeam-oak forests. The characteristic taxa of the Likhva interglacial dendroflora in this region were Picea sect. Omorica, P. sect. Eupicea, Pinus sect. Strobus, P. sylvestris, Betula sect. Costatae, B. pendula, B. pubescens, Juglans regia, Fagus orientalis, Quercus robur, Ostrya sp., Carpinus betulus, C. orientalis. Daphne sp. etc.

Considering the climatorrhythmics of the modern interglacial epoch in the context of the natural process of the entire Neo-Pleistocene and comparing the results of the palynological study of Holocene deposits of the East European Plain (Khotinsky, 1977; Bolikhovskaya, 1988, 1990a; Bolikhovskaya, Bolikhovsky, Klimanov, 1988; Holocene paleoclimates..., 1988; Late Glacial Paleoclimates..., 1989; Klimanov, 1996) with detailed reconstructions Based on the results of the climatophytocenotic successions of previous interglacial epochs performed for almost continuous profiles of the loess-soil formation (Bolikhovskaya, 19956), it can be assumed that the Holocene climatic rhythm passed only the thermoxerotic stage. Thus, in the next millennia, we should expect to-

page 15

Table 1.

Age and duration of the Neo-Pleistocene glacial and interglacial stages

Stage

MIS

Age range, thousand years

Duration, thousand years

Holocene

1

10 - 0

10

The Valdai Glaciation

2 - 4

-70 - 10*

-60*

Mikulinsky interglacial area

5

-140/145 - 70*

-70/75*

Dnieper glaciation

6

-200 - 140/145*

-55/60*

Cherepet Interglacial area

7

-235 - 200*

-35*

Zhizdrinsky cold snap

8

-280 - 235*

-45*

Chekalinsky interglacial area

9

-340 - 280*

-60*

Kaluga cold snap

10

-360 - 340*

-20*

Likhvin Interglacial period

11

-455 - 360*

-95*

Oka glaciation

12 - 14

-535 - 455*

-80*

Muchkap interglacial area

15

-610 - 535*

-75*

Don glaciation

16

659 - 610*

-50*

Semiluk interglacial area

17

712 - 659**

53**

Devitsky (Setun) glaciation

18

759 - 712**

47**

Gremyachyevsky interglacial zone

19

787 - 759**

28**

Pokrovskoe (Likovskoe) glaciation

20

815 - 787**

28**

Peter and Paul Interglacial period

21

860 - 815**

45**

-----

* According to A. N. Molodkov (Molodkov and Bolikhovskaya, 2002).

** From [Bassinot et al., 1994].

6. 450-thousand-year cycles in the development of vegetation and climate of the Neo-Pleistocene (according to the palynological study of the Otkaznoye section). The time scale and duration of climatic rhythms are given based on the results of EPR definitions by A. N. Molodkov [Molodkov and Bolikhovskaya, 2002]. The age of isotopic stages is 17-20 according to [Bassinot et al, 1994].

page 16

It is likely that the onset of the thermohygrotic stage of the interglacial period, i.e., a climate warmer and wetter than that which existed during the optimum of the Atlantic Holocene period. Analysis of the paleoclimatic curves obtained for the last 10 thousand years in various regions of Northern Eurasia allowed us to conclude that from the end of the Subboreal period (approximately 2.2 - 2.5 thousand years AGO) to the present, all climate fluctuations measured over centuries and shorter periods of time occur against the background of endothermal cooling of the Holocene.

Orientation and metachronism in the development of interglacial flora and vegetation of the Neo-Pleistocene

Analysis of the published data suggests a common point of view of researchers on the nature of directed climate change during the Pleistocene. According to experts, during this period there was a growing cold snap; the climate of each interglacial or ice age was colder and more continental than the climate of the previous interglacial or glacial period.

Summarizing the paleobotanical data on the interglacial strata of the continent, V. P. Grichuk came to the conclusion that in different regions of Europe, "belonging to territories with different physical and geographical, and primarily climatic, conditions, flora changes during the Quaternary period were very similar. The main one was the process of gradual depletion of the dendroflora composition, which is expressed in a regular decrease in the number of geographical groups of genera and the number of genera themselves that composed the flora of successive interglacial epochs " [1989, p. 29]. Concretizing this conclusion, he pointed out the impossibility of a paleogeographic situation where "an interglacial epoch with a flora poorer in exotic elements precedes an interglacial epoch with a richer flora" [Ibid., p. 30]. In other words, interglacial deposits with poorer Neogene relict flora should be considered younger than interglacial deposits containing richer Neogene relict flora.

Subsequent studies have shown that this erroneous, in our opinion, paleobotanical criterion of stratigraphy is due to the lack of data on a number of early and middle neo-Pleistocene interglacials and the fact that reconstructions were carried out on the basis of fossil floras of sections located at considerable distances from each other, in which deposits of only one Pleistocene interglacial epoch were represented (or studied). The results of a detailed palynological analysis of the Likhvin (Chekalin), Strelitsa, and Otkaznoye sections, which contain horizons of all Neo-Pleistocene units, revealed the real sequence of palynoflora and vegetation changes in the glacial-periglacial and extraglacial zones of the East European Plain (Bolikhovskaya, 1995b). The obtained data did not confirm the idea that everywhere each subsequent interglacial epoch should be characterized by a flora that is poorer in exotic elements than the flora of the previous interglacial period. Comparison of successive series of reconstructed climatophytocenotic successions, as well as interglacial, periglacial, and glacial palynoflora in these most complete sections of the Dnieper glacial tongue moraine, Don glacial tongue moraine, and extraglacial regions, which contain information about the almost continuous course of development of natural systems in the early, Middle, and late neo-Pleistocene, revealed a significantly different pattern in the development of flora and vegetation.

It is established that the process of impoverishment of interglacial floras with exotic elements, which undoubtedly grew in the Late Cenozoic as a whole, was disrupted at certain stages of the early or Middle Neo-Pleistocene by the appearance of floras that had a more diverse composition of taxa and a richer set of Neogene relics than the flora of the previous Interglacial period. These "disruptions" in the process of directed change were regionally specific.

In the modern steppe and forest-steppe regions of the East European Plain, the flora of the Muchkap Interglacial period, which was a forest-type flora, was significantly richer in the composition of genera and species of woody and shrubby plants, the number and diversity of Neogene relics than the forest-steppe flora of the preceding Gremyachyevsky and Semiluk interglacials. For example, the data obtained showed that in the extreme south-east of the East European Plain on the territory of the Middle Kuma gremyachyevskaya (Early Il'inskaya) interglacial flora, which includes approx. 50 taxa (including cedar Cedrus sp., spruce Picea sect. Omorica, birch Betula sect. Costatae, beech Fagus orientalis, oak Quercus robur, Q. petraea, Q. castaneifolia, Q. ilex, hornbeam Carpinus caucasica, C. betulus, hornbeam Carpinus orientalis, hop Ostrya cf. carpinifolia, bear walnut Corylus colurna, linden Tilia platyphyllos, T. tomentosa, T. cordata, mulberry Morus sp. et al.), and the poorer Semiluk (Late Ilinskian) interglacial flo-

page 17

ra contains a smaller number of Neogene relics and taxa in general than the subsequent Muchkap flora. The Muchkap forest flora is represented by 90 taxa, including hemlock Tsuga canadensis, cedar Cedrus sp., and cedar pine Pinus sect. Cembra, Lapina Pterocarya pterocarpa, Hickory Carya sp., walnut Juglans cinerea, J. regia, Liquidambar, chestnut Castanea sp., frame Celtis sp., Holly Ilex aquifolium, Beech Fagus orientalis, F. sylvatica, hornbeam Carpinus caucasica, C. betulus, Hornbeam Carpinus orientalis, Ivy Hedera sp., bereskletokras Kalonymus Staphylea sp., wolfberry Daphne sp., Rhododendron Rhododendron sp., chistoost Osmunda regalis, O. claytoniana, O. cinnamomea, etc. In the central regions of the modern forest zone, according to the same indicators, the flora of the Likhva s. str. interglacial period, during the thermal maximum of which broad-leaved oak-hornbeam forests dominated in the northwestern sector of the Central Russian Upland, was significantly richer than the flora of the previous Muchkap interglacial period, which was characterized by the predominance of spruce-broad-leaved and elm-oak forests in the warmest phases. Characteristic and representative taxa of the Middle Pleistocene Likhva flora of the Upper Oka region, containing 90 names, include hemlock Tsuga canadensis, yew Taxus baccata, fir Abies alba, spruce Picea sect. Omorica, P. excelsa, cedar pine Pinus sect. Cembra, P. sect. Strobus, scots pine P. sylvestris, larch Larix sp., birch Betula sect. Costatae, B. pendula, B. pubescens, Grey walnut Juglans cinerea, walnut J. regia, Lapina Pterocarya fraxinifolia, boxwood Buxus sp., hornbeam Carpinus betulus, chestnut Castanea sativa, Holly Ilex aquifolium, beech Fagus sylvatica, F. orientalis, oak Quercus castaneifolia, Q. petraea, Q. robur, Q, pubescens, Zelkova sp., Celtis sp.frame, elm Ulmuspropinqua, U. laevis, U. campestris, ash Fraxinus sp., linden Tilia platyphyllos, T. tomentosa, T. cordata, maple Acer sp., bear walnut Corylus colurna, hazel Corylus avellana, alder Alnus glutinosa, A. incana, Amur cod Ligustrina amurensis, Rhododendron Rhododendron sp., Vitis sp.grapes, waxwort Myrica sp., chistoost Osmunda claytoniana, O. cinnamomea, Salvinia Salvinia natans, etc. B is significantly more limited-

Table 2.

Composition of Neogene relics in the flora of the Southern East European Plain*

Gender

N32

QI

QII

QIII

QIV

Tsuga

+

Taxodium

+

Taxus

+

Nyssa

+

Zelkova

+

Ilex

+

Pterocarya

+

+

Carya

+

+

Ostrya

+

+

Rhus

+

+

Liquidambar

+

+

Fagus

+

+

+

Castanea

+

+

+

Myrica

+

+

+

Abies

+

+

+

+

Picea sect. Omorica

+

+

+

+

Pinus s. g. Haploxylon

+

+

+

+

Juglans

+

+

+

+

Mows

+

+

+

+

Osmunda

+

+

+

+

Carpinus

+

+

+

+

+

Number of births

21

15

9

7

1

* By: [Bolikhovskaya, 19966].

page 18

Table 3.

Composition of geographical groups of dendroflora genera in Pleistocene deposits of the Otkaznoye section (Eastern Ciscaucasia)

page 19

However, in terms of the number of Neogene relics and taxa, only Tsuga canadensis and Picea sect are represented in the list of Early Pleistocene Muchkap flora of the Upper Oka. Omorica, P. sect. Eupicea, Abies sp., Pinus sect. Cembra, P. sect. Strobus, Larix sp., Rhus sp., Carpinus betulus, C. orientalis, Fagus sylvatica, Quercus robur, Q. pubescens, Tilia platyphyllos, T. cordata, Ilex aquifolium, Ulmus laevis, U. glabra, U. campestris, Osmunda cinnamomea, O. claytoniana, and Cedrus sp. absent from younger interglacial floras. (autochthonous element of long-distance drift), Tilia amurensis, Osmunda regalis, woodsia fern Woodsia manchuriensis, W. fragilis, which we assigned to the representative species of the Muchkap interglacial period in the center of the Russian Plain (Bolikhovskaya, 19956). These data are also confirmed by materials on the flora of Early Pleistocene interglacial sediments from other sections in the center of the East European Plain-Akulovo, Balashikha, Podrudnyansky, Glazovo, Polnoye Papino, etc., which V. P. Grichuk mistakenly attributed to the post-Tikhvin interglacial formations in accordance with the above-mentioned palinostratigraphic criterion (1989, Tables 19, 20, and 28)..

Thus, on the basis of new and more complete paleobotanical data than previously obtained, the regional specificity of directed changes in Pleistocene floras is revealed. It is established that the directed process of impoverishment of interglacial neo-Pleistocene floras by Neogene relics and a decrease in the number of plant genera and species involved in them in the areas of modern steppe and forest-steppe zones occurred starting from the Muchkap interglacial, and in the areas of modern forest zone - starting from the Likhva s. str.interglacial. At the same time, a ubiquitous pattern has also clearly emerged. It is established that the regularity of the directional development of the flora of the East European Plain in the Pleistocene, expressed in the reduction and disappearance of genera alien to the modern dendroflora of this territory, is clearly traced when comparing the entire set of interglacial floras of one link of the Neo-Pleistocene with integral interglacial floras of the other link. This pattern of directed flora development, which is common to all regions of Northern Eurasia, is clearly illustrated, for example, by the summary data on the composition of Neogene relics in the early, Middle, and Late Pleistocene floras of the southern regions (Table 1). 2), as well as on the composition of geographical groups of dendroflora genera in the palynoflora of the Otkaznoye section (Table 3).

An analysis of representative paleobotanical materials describing successive changes in flora across the most complete sections of the Neo-Pleistocene indicates that only the Early Pleistocene interglacial floras as a whole have a greater variety of taxa and contain a greater number of genera and species alien to modern flora than the Middle Pleistocene interglacial floras. The Late Pleistocene floras are also inferior to the Middle Pleistocene flora assemblage.

According to the data obtained on fossil palynoflora in recent decades, along with the general (but different than previously thought) regularity of the directional development of flora and vegetation in different regions of the East European Plain, regional features of their evolution during the Neo-Pleistocene also manifested themselves. The peculiarity of the development of regional flora and plant communities was determined by global climatic processes in the Neo-Pleistocene and the geographical position of the areas of the studied sections of Late Cenozoic deposits. The position of the region in the system of climatic and botanical paleozonality determined the ratio of heat and moisture availability of vegetation in specific interglacial epochs, which, in turn, determined the degree of participation of thermophilic elements and Neogene relics in the composition of paleoflora.

Patterns of spatial differentiation of vegetation cover in interglacial and glacial epochs of the Neo-Pleistocene

Interglacial vegetation. Reconstructions of the composition of flora and formations of paleoregentivity of climatic optima of various interglacial epochs of the Neo-Pleistocene, obtained for all regions of the East European Plain characterized by palynological data to date, indicate climatic conditions close to the climatic conditions of the Holocene optimum and modern climatic conditions on the territory of these regions or milder. The dominant types of interglacial forest vegetation extending from the northern coast far to the south were boreal (small-leaved and coniferous-birch, pine, spruce, etc.) and non-moral (broad-leaved and coniferous-broad-leaved) forests. Steppe vegetation, represented by various steppe and forest-steppe formations, had a much more limited distribution. Tundras and forest tundras that are now characteristic of the coastal areas of the Barents Sea, as well as semi-deserts and deserts that are currently developed in the Caspian Lowland, according to the palynospectras of Neo-Pleistocene interglacial deposits, in

page 20

Interglacial stages were absent on the territory of the East European Plain (V. P. Grichuk, 1989; Bolikhovskaya, 2004).

The zonal differentiation of the vegetation cover of all interglacial epochs on the territory of the East European Plain was relatively simple: the vast forest zone to the south was replaced by forest steppes and steppes. The latter merged with the foothill steppes of the Caucasus and the Crimea, which were replaced further south by foothill forest-steppes and forests. At the same time, the diversity of interglacial forest formations was significant. For example, for the interglacial periods of the last 900 thousand years in the glacial-periglacial and extraglacial regions of the plain, the following set of dominant forest formations was reconstructed (Bolikhovskaya, 2004): pine-birch woodlands; larch-pine-birch woodlands; pine-birch forests; spruce forests; birch woodlands with an admixture of broad-leaved species; birch forests with an admixture of broad-leaved species pine-birch forests with an admixture of broad-leaved species; birch-pine forests with an admixture of broad-leaved species; spruce-pine-birch forests with an admixture of broad-leaved species; pine-spruce forests with an admixture of broad-leaved species; birch-broad-leaved forests; pine-birch-broad-leaved forests; spruce-pine-birch-broad-leaved forests; pine-cedar-broadleaf forests; pine-spruce-broadleaf forests; spruce-broadleaf forests; spruce-fir-broadleaf forests; broadleaf (Quercetum mixtum) forests; shiblyak oak and hornbeam forests; coniferous forests with individual subtropical elements; mixed coniferous-broadleaf forests with individual subtropical elements; spruce-broadleaf forests with subtropical elements; polydominant broad-leaved forests of walnut, beech, hornbeam, oak, linden, elm and other species; broad-leaved forests with subtropical elements; polydominant broad-leaved forests with subtropical elements; broad-leaved shade forests dominated by hornbeam Carpinus betulus.

There was also a wide variety of forest communities in the composition of forest-steppe and steppe landscapes of interglacial epochs.

Periglacial vegetation. Let us consider the features of the vegetation cover of ice ages, represented by various types of periglacial vegetation.

K. K. Markov [Markov et al., 1968] wrote that the term "periglacial" literally means "preglacial", which implies the presence of an ice sheet in the rear of the periglacial region. However, as he emphasized, this understanding is incorrect and too narrow, since the periglacial climate, periglacial landscapes and the corresponding periglacial vegetation develop not only in the area of cover glaciation, but also in the areas of permafrost deposits, under conditions of underground glaciation. According to our data, the main differences between periglacial and interglacial palynospectra are as follows:: 1) significantly lower content or complete absence of pollen of thermophilic elements of dendroflora and microfossils of heat-and moisture-loving herbaceous plants; 2) autochthonous combination of microstates of tundra, boreal forest and desert-steppe flora; 3) a significant role of pollen and spores of plants growing today in various edaphic conditions - in swampy and meadow habitats, areas with eroded soil cover, ecotopes with saline substrates that indicate the existence of permafrost (Bolikhovskaya, 1999).

Phytocenotic interpretation of periglacial palynospectra and their typification are a significant challenge in the complex of palynological studies of Pleistocene deposits. The well-known conventionality of terms and definitions used in all works devoted to the characterization and spatial-zonal differentiation of periglacial vegetation is explained by the lack of direct analogues among modern phytocenoses and the incompleteness of paleobotanical information. According to the volume of collected paleobotanical data, the periglacial paleophytocenoses of glacial stages were reconstructed and differentiated depending on the participation of certain floristic elements in the periglacial palynospectra that characterize them - arctoalpine, hypoarctic, boreal-forest, steppe, desert-steppe, etc. steppe elements, and tundra-forest - steppe elements-according to similar spectra, but with a higher content of such boreal dendroflora elements as pine, larch, birch, willow, etc. Periglacial tundras are characterized by spectra dominated by tundra elements; periglacial forest tundras are recorded by spectra dominated by tundra and boreal forest elements. Periglacial woodlands are identified by the spectra with the dominant role of boreal-forest elements; periglacial forest-steppes are distinguished by the spectra in which boreal-forest and steppe elements prevail; periglacial steppes are characterized by the spectra with the predominance of steppe elements. A group of extraglacial vegetation-bearing formations is also identified.-

page 21

typical of the southernmost regions of Northern Eurasia. They are reconstructed from periglacial spectra, which are dominated by microstates of representatives of forest, steppe, and desert-steppe floras; the content of thermophilic elements is noticeable (but much lower than in interglacial optimal floras), and the role of cryophytes, which are always present and usually represented by the remains of Betulafruticosa (rarely Betula nana, Alnaster fruticosus, etc.), is insignificant. Depending on the share of edificatory (forest, steppe, desert - steppe, and desert) floristic elements in the palino spectra, the reconstructed phytocenoses are called extraglacial: forests, woodlands, forest steppes, steppes, and semi-deserts.

Judging by the diversity of palynospectres of glacial stages, including interstadial and interphasial intervals, the complete zonal series of Pleistocene periglacial vegetation of the East European Plain includes three groups of paleospecies types: 1) ultraperiglacial tundras and tundroles-steppes; 2) periglacial tundras, forest-tundras, woodlands, forest-steppes, steppes; 3) extraglacial semi-deserts, steppes, forest-steppes,

Figure 7. Climatostratigraphy and main stages of changes in zonal vegetation types of the East European Plain (within modern mixed (1) and broad-leaved (2) forests) for the last 200 thousand years. Absolute age according to A. N. Molodkov [Bolikhovskaya and Molodkov, 2005]. pt - periglacial tundras; plt - periglacial forest tundras; ts - tundro-steppes; tle - tundro-forest steppes; prl - periglacial woodlands; pl - periglacial forests; ppp - periglacial semi - deserts; pet - periglacial steppes; pl - periglacial forest steppes; est - extraglacial steppes; ele - extraglacial forest steppes; earle-extraglacial woodlands; el - extraglacial forests; ml - interglacial forests; mls - interglacial forest-steppes; met - interglacial steppes.

page 22

Figure 8. Climatostratigraphy and main stages of changes in zonal vegetation types in the East European Plain (within modern steppes and forest steppes) in the last 200 thousand years. Absolute age according to A. N. Molodkov (Bolikhovskaya and Molodkov, 2005). See Figure 7 for the reference data.

woodlands and forests. Ultraperiglacial and periglacial (or stenoperiglacial) plant communities and flora were formed in a permanently harsh glacial climate. Extraglacial plant communities and flora also developed under the conditions of glacial epochs, but either in areas protected by orographic barriers, or in areas most remote from the edge of the ice sheets, which experienced a weaker influence of the glacial climate, and in the south, possibly, the warming effect of sea basins [Ibid.].

The zonal series of the reconstructed Pleistocene periglacial vegetation of the glacial-periglacial zone of the East European Plain within the Desna-Dnieper, North-Central Russian, and Oka-Don oblasts consists of: periglacial tundras, forest tundras, tundrosteps, tundroles-steppes, periglacial steppes, forest steppes, pine-birch woodlands, larch-pine-birch woodlands, extraglacial steppes, forest steppes, pine and birch woodlands. The paleoregenticity of the cold epochs is complemented by the types of periglacial vegetation of the Eastern Ciscaucasian extraglacial region: periglacial semi-deserts and dry steppes, steppes, forest-steppes, birch and coniferous-birch woodlands, extraglacial forest-steppes, birch woodlands, spruce and cedar-spruce forests, as well as a zonal series of periglacial vegetation of the Dniester-Prut extraglacial region: tundra forest-steppes, periglacial forest-steppes, steppes, pine woodlands, pine forests, extraglacial steppes, dry steppes, forest steppes, pine forests (Bolikhovskaya, 1995b).

On the hyperzonality of the Neo-Pleistocene vegetation cover. Comparison of zonal and local scales

page 23

The comparison of subzonal types of periglacial vegetation with similar scales of reconstructed interglacial vegetation showed that quantitatively zonal and subzonal types of periglacial vegetation significantly exceeded zonal and subzonal vegetation types of interglacial epochs. The validity of this conclusion about the regularities of spatial differentiation of interglacial and periglacial vegetation covers is confirmed by the author's reconstructions of successive vegetation changes in the southern half of the East European Plain over the past 200 thousand years (Figs. 7, 8), as well as maps of the paleozonality of the Late Valdai climatic pessimum and optimal phases of the Mikulinsky interglacial period compiled by V. P. Grichuk (1989). (table 4).

During the Interglacial epochs, forest vegetation types were most widespread on the territory of the Eastern European Plain. During glacial epochs, open periglacial landscapes dominated here - tundras and tundroles-steppes, periglacial tundras, forest tundras, steppes, forest steppes, woodlands, etc.The phenomenon of so-called hyperzonality was characteristic of both interglacial optima and glacial climatic rhythms. Materials on periglacial vegetation, which were first obtained in such a large volume (Bolikhovskaya, 1995b), allowed us to establish the following regularity: the zonal and subzonal differentiation of vegetation cover in the cold stages of the Neo-Pleistocene was more significant than the zonal and subzonal differentiation of vegetation cover in the warm stages. We also note that this pattern is also observed when comparing the vegetation cover of endothermal cooling and optimal phases of interglacial epochs. The differentiation of vegetation cover during endothermal cooling of interglacial periods was more significant than the differentiation of vegetation cover during climatic optima of thermochrons.

See Table 4.

Interglacial and periglacial vegetation types of the late Pleistocene in the Russian Plain*

Vegetation type of the climatic optimum of the Mikulinsky interglacial period

Vegetation type of the Late Valdai Glaciation climate pessimum

Boreal.

1-birch and pine woodlands; 2-birch and mixed coniferous forests; 3-spruce and birch forests with a small participation of oak and elm; 4-spruce and birch forests with hornbeam, oak and linden

Immoral.

5-hornbeam forests with oak, birch and spruce; 6-hornbeam forests with linden and oak; 7-hornbeam (in the west) and mixed broadleaf forests with spruce; 8-hornbeam and pine-broadleaf forests; 9-broadleaf forests of hornbeam (west of the Volga), linden and oak; 10-deciduous and coniferous-deciduous forests of complex composition (Euxine formations)

Steppe.

11-meadow steppes in combination with forests of hornbeam and oak (in the west) and oak (in the east); 12-grass steppes

Periglacial-tundra:

1-arctic deserts and shrub-moss tundra groups;

2-combination of tundra and sedimentary associations with larch, birch, and pine woodlands (subglacial vegetation, northern variant);

3-combination of steppe and tundra associations with pine and birch woodlands (subglacial vegetation, southern variant);

4-moss-shrub plain and mountain associations combined with birch and spruce woodlands (Ural-West Siberian formations)

Periglacial steppe:

5-meadow steppes with formations of birch, pine and spruce forests, tundra groups and halophilic groups of steppe character;

6-meadow steppes with formations of birch and pine forests and halophilic steppe communities; 7-meadow steppes with formations of birch and pine (with oak, elm and linden) forests; 8-mixed grass and grass steppes with halophilic groupings
Boreal:

9-formations of coniferous forests in the west with a small participation of broad-leaved species

Immoral:

10 - formations of non-moral forests of oak and linden with a large participation of conifers;

11 - formations of nemoral coniferous-deciduous and broad-leaved forests

Steppe:

12-grass and grass steppes;

13-sagebrush steppes with pontic elements (Sueda confusion, etc.);

14-meadow vegetation with halophilic clusters on drained shelves and saline sea coasts

* By: [Grichuk V. P., 1989].

page 24

Conclusion

Detailed reconstructions of floristic, phytocenotic, and climatic successions in a number of characteristic stratoregions of the East European Plain that differ in the history of paleogeographic development made it possible to clarify the structure of climatic rhythmicity - the number of interglacial and glacial (cold) rhythms within the Neo-Pleistocene and the features of climatorrhythmics within warm and cold epochs. They radically changed the understanding of the course of directional changes in flora and vegetation in the Neo-Pleistocene and the specifics of spatial differentiation of vegetation cover during interglacial and glacial epochs.

1. The spatial differentiation of periglacial vegetation was more significant than the spatial differentiation of interglacial vegetation cover. The diversity of zonal and subzonal vegetation types in cold periods was greater than the diversity of zonal and subzonal vegetation types in interglacial epochs.

2. Changes in the natural environment of the East European Plain during the Neo-Pleistocene were caused by changes in 17 global climatic rhythms (nine interglacials and eight glaciations or glacial-grade cooling events separating them). Within glacial and interglacial rhythms, more fractional climatostratigraphic units are distinguished: endothermal cooling, thermoxerotic and thermohygrotic stages in interglacial climatic rhythms; stadials, interstadials, interphases, cryohygrotic and cryoxerotic stages in glacial climatic rhythms.

3. A comparative analysis of the almost continuous sequence of climatophytocenotic and floristic successions revealed the fourth most important pattern in the development of the natural environment - cyclicity.

Two long cycles of changes in the flora, vegetation, and climate of the East European Plain in the Neo-Pleistocene were traced, which determined the natural features of each interglacial and glacial stage.

The correlation of various paleoclimatic events (reconstructed from palynological data in continental regions identified in the paleoshelf zone of Northern Eurasia and dated by the EPR method, as well as presented on the oxygen isotope scale of oceanic sediments) performed by us and A. N. Molodkov [Bolikhovskaya and Molodkov, 1999; Molodkov and Bolikhovskaya, 2002] allowed us to determine the absolute age and the duration of interglacial and glacial climatic rhythms of the last 900 thousand years (see Table 1).

According to these chronostratigraphic data, the established cycles in the development of the natural environment of the East European Plain had a duration of approximately 450 thousand years. Each such cycle spanned four interglacial and four glacial epochs. All the interglacial periods of the "Kaluga cooling - Holocene interglacial" cycle were characterized by a more continental climate and significantly lower participation of Neogene relics and plants alien to modern flora in the vegetation cover than their interglacial counterparts of the "Pokrovskoe cooling - Likhva interglacial" cycle. Each of the interglacial or glacial stages of the younger 450-millennial cycle had its own paleogeographic counterpart in the previous 450-millennial cycle (see Figure 6).

Cyclicity, as well as directionality, rhythmicity, and metachronism, is one of the main regularities of changes in the natural environment in the Neo-Pleistocene. The establishment of this regularity brings to a new level the prospects of palynoclimatostratigraphic studies not only in solving the problems of stratigraphy and paleogeography of the Pleistocene (determining the geological age of sediments, periodization of paleogeographic events and paleoreconstructions of the natural environment), but also in predictive modeling of changes in various components of the natural environment.

Acknowledgements

Long-term expedition work was carried out by the author as part of teams that carried out interdisciplinary studies of reference sections of the Pleistocene of Northern Eurasia. Chronostratigraphic definitions of paleogeographic stages were obtained jointly with A. N. Molodkov, Head of the Laboratory of Quaternary Geochronology at the Institute of Geology of Tallinn University of Technology (Estonia). The color design of the illustrations was made by A.V. Abdulmanova. The author expresses his heartfelt gratitude to all his colleagues for their cooperation and assistance.

List of literature

Alekseev M. N., Borisov B. A., Velichko A. A., Gladenkov Yu. B., Lavrushin Yu. A., Shik S. M. On the general stratigraphic scale of the quaternary system. Geological correlation. - 1997. - Vol. 5, N 5. - pp. 105-108.

Bolikhovskaya N. S. Vegetation of the Likhva interglacial zone according to palynological analysis

page 25

Oka-Dnieper deposits of the Chekalinsky section (Tula region) // Lead. Moscow State University of Ser. Geogr., 1974, No. 3, pp. 95-96.

Bolikhovskaya N. S. Palynologiya loessov i pogrebennykh pochv Russkoi ravniny [Palynology of loess and buried soils of the Russian Plain]. Problemy obshchey fizicheskoy geografii i paleogeografii [Problems of general physical geography and paleogeography], Moscow: Izd. Moscow State University, 1976, pp. 257-277.

Bolikhovskaya N. S. Vegetation of the Mikulinsky interglacial zone according to palynological analysis of polygenetic fossil soil near the Molodova I site. A unique Mousterian settlement on the middle Dniester River, Moscow: Nauka Publ., 1982, pp. 145-154.

Bolikhovskaya N. S. K istorii rastitel'nosti i klimata Podmoskovnoi Meshchera v holocene [On the history of vegetation and climate of the Moscow Meshchera region in the Holocene]. Palaeoklimaty holocene evropeyskoy territorii SSSR [Paleoclimates of the Holocene of the European territory of the USSR], Moscow: Nauka, 1988, pp. 76-85.

Bolikhovskaya N. S. Palynoindication of changes in landscapes of the Lower Volga region in the last ten thousand years // Voprosy geologii i geomorphologii Kaspiyskogo morya [Issues of Geology and Geomorphology of the Caspian Sea], Moscow: Nauka Publ., 1990a, pp. 52-68.

Bolikhovskaya N. S. Stratigraphy and paleogeography of the loess-soil formation of Northern Eurasia (based on palynological data), in Quaternary stratigraphy and Events of Eurasia and the Pacific region. Yakutsk: Publishing House of the Yakut Scientific Center of the Siberian Branch of the USSR Academy of Sciences, 19906, part 1, pp. 24-26.

Bolikhovskaya N. S. Osnovnye problemy paleogeografii loessov i fossilovykh pochv [Basic problems of paleogeography of loess and fossil soils]. Results of Science and Technology, Moscow: VINITI Publishing House, 1991, vol. 7: Paleogeography, pp. 41-69.

Bolikhovskaya, N. S., Stratigraphy and correlation of the Late Pleistocene of the Russian Plain based on a detailed palynological study of the Arapovichi section, Tendenciya razvitiya prirody v sovremennoe vremya (okean - shelf - mainland), Moscow: Izd. Moscow State University, 1993, pp. 102-126.

Bolikhovskaya N. S. Periglacial and interglacial landscapes of the Pleistocene of the Eastern Ciscaucasian loess region. - M.: VINITI, 1995a. - 125 p. - Dep. in VINITI 10.01.95, N 52-B95.

Bolikhovskaya N. S. Evolution of the loess-soil formation of Northern Eurasia, Moscow: Moscow State University Publishing House, 19956, 270 p.

Bolikhovskaya N. S. Palynological materials on stratigraphy and paleogeography of the Lower and Middle Pleistocene of the glacial-periglacial zone of the Russian Plain // Quaternary Geology and Paleogeography of Russia, Moscow: GEOS, 1997, pp. 25-37.

Bolikhovskaya, N. S., Typification experience of Pleistocene periglacial vegetation in loess areas of the glacial and extraglacial zones of the Russian Plain, Byul. Commission fees for the project. Thursday, October. - 1999. - N 63. - p. 20-32.

Bolikhovskaya N. S. Osnovnye etapy razvitiya rastitel'nosti i klimata v pleistocene [The main stages of vegetation and climate development in the Pleistocene]. Moscow: GEOS, 2004, vol. 1: Structure, dynamics and evolution of Natural geosystems, pp. 561-582.

Bolikhovskaya N. S. Osnovnye zakonomernosti razvitiya rastitel'nosti i klimata Vostochno-Evropeiskoi ravniny v poslednih 900 thousand let [Basic laws of vegetation and climate development in the Eastern European Plain in the last 900 thousand years]. Moscow: Moscow State University, 2005, pp. 159-181.

Klimanov V. A. Bolikhovskiy V. F., Bolikhovskaya N. S. Klimaticheskie i kriogennye faktory razvitiya pefyanikov Evropeyskogo Severo-Vostoka SSSR v holocene [Climatic and cryogenic factors of development of peat bogs of the European North-East of the USSR in the Holocene].

Bolikhovskaya, N. S. and Boyarskaya, T. D., Some features of the flora and vegetation of the Likhva Interglacial region in the Oka Valley, in Novosteyshaya tectonika, novosteyshye otlozheniya i cheloveka, Moscow: Izd. of Moscow State University, 1982, pp. 123-130.

Gunova V. Bolikhovskaya N. S., Sobolev V. M. Osnovnye etapy razvitiya periglacial'noi rastitel'nosti tsentra i yuga Russkoi ravniny v period of existence of mammoth fauna [The main stages of development of periglacial vegetation in the center and south of the Russian Plain during the existence of mammoth fauna]. Mamont i ego okruzhenie: 200 let izucheniya [Mammoth and its environment: 200 years of study], Moscow: GEOS, 2001, pp. 168-187.

Molodkov A. N. Bolikhovskaya N. S., On the correlation of continental and marine quaternary deposits of Northern Eurasia based on palynological data and EPR dating results, in Aktual'nye problemy palynologii na poroge tretego millenniya (Actual problems of palynology on the threshold of the third millennium). Moscow: Publishing House of the Institute of Geology and Development of Combustible Minerals, 1999, pp. 25-53.

Molodkov A. N. Bolikhovskaya N. S., Correlation of climatic fluctuations of the last 200 thousand years reconstructed from palynological materials of loess-soil sections and EPR-chrono stratigraphy data of marine deposits of Northern Eurasia, Biostratigraphic criteria for dissection and correlation of Phanerozoic deposits of Ukraine. - Kiev: National Publishing House. Academy of Sciences of Ukraine, 2005, pp. 264-270.

Valueva M. N., Serebryany L. R. Reconstruction of vegetation of the Yaroslavl Trans-Volga region in the Mikulinsky interglacial period. Commission fees for the project. quarter of the period. - 1978. - N 48. - p. 113-122.

Veklich M. F. Paleoetapnost ' i stratotipy pochvennykh formatsii verkhnego Cenozoic [Paleoetapity and stratotypes of Upper Cenozoic soil formations]. Kiev: Nauk, dumka Publ., 1982, 203 p.

Veklich M. F. Problemy paleoklimatologii [Problems of paleoclimatology]. Kiev: Nauk, dumka Publ., 1987, 192 p. (in Russian)

Veklich M. F. Osnovy paleolandschafovedeniya [Fundamentals of Paleolandscape science]. Kiev: Nauk, dumka Publ., 1990, 192 p. (in Russian)

Velichko, A. A., On the question of the sequence and fundamental structure of the main climatic rhythms of the Pleistocene, Voprosy paleogeografii pleistocene lednikovykh i periglacialnykh oblastov, Moscow: Nauka, 1981, pp. 220-246.

Velichko A. A. Struktura termicheskikh izmenenii paleoklimatov meso-cenozoic po materialam izucheniya Vostochnoi Evropy [Structure of thermal changes in Meso-Cenozoic paleoclimates based on the study of Eastern Europe].

Velichko A. A. Osnovnye zakonomernosti evolyutsii landshaftov i klimata v cenozoic [Basic laws of the evolution of landscapes and climate in the Cenozoic]. Izmenenie klimata i landshaftov za poslednih 65 mn'nykh let [Climate and landscape change over the last 65 million years].

Velichko, A. A., Pisareva, V. V., and Faustova, M. A., Glaciations and interglacials of the East European Plain in the Early and Middle Pleistocene, Stratigrafiya. Geological correlation. - 2005. - Vol. 13, N 2. - pp. 84-102.

Grichuk V. N. Rastitel'nost ' Russkoi ravniny v ranne - i srednechetvertichnoe vremya [Vegetation of the Russian Plain in the Early and Middle Quaternary periods].

page 26

Grichuk V. P. Stratigraphic division of the Pleistocene on the basis of paleobotanic materials / / Chronology and climates of the Quaternary period, Moscow: Publishing House of the USSR Academy of Sciences, 1960, pp. 27-35.

Grichuk V. P. Fossils of flora as a paleontological basis for the stratigraphy of quaternary deposits / / Relief and stratigraphy of quaternary deposits of the North-west of the Russian Plain, Moscow: Publishing House of the USSR Academy of Sciences, 1961, pp. 25-71.

Grichuk V. P. Glacial floras and their classification // The last glacial cover in the north-west of the European part of the USSR, Moscow: Nauka, 1969, pp. 57-70.

Grichuk V. P. Istoriya flory i rastitel'nosti Russkoi ravniny v pleistocene [History of flora and vegetation of the Russian Plain in the Pleistocene]. Moscow: Nauka Publ., 1989, 183 p.

Grichuk M. P., Grichuk V. P. On preglacial vegetation on the territory of the USSR // Periglacial phenomena on the territory of the USSR. Moscow: Moscow State University Press, 1960, pp. 66-100.

Grichuk V. P., Zaklovskaya E. D. Analysis of pollen and spore fossils and its application in paleogeography, Moscow: Geografgiz, 1948, 222 p.

Dodonov A. E. The Quaternary period of Central Asia. Stratigraphy, correlation, and paleogeography, Moscow: GEOS, 2002, 250 p. (Proc. of the Geological Institute of the Russian Academy of Sciences, issue 546).

Elovicheva Ya. K. New sections of the Mikulinsky (Muravinsky) interglacial deposits of the Smolensk region // Materials of geological study of the territory of Belarus. Minsk: Nauka i tekhnika Publ., 1981, pp. 127-137.

Yelovicheva Ya. K. Paleogeography and chronology of the main stages of the development of the natural environment of the anthropogen of Belarus (based on palynological data): Abstract of the dissertation of Doctor of Geographical Sciences. - Kiev, 1992. - 52 p.

Zubakov, V. A., Planetary sequence of climatic events and geochronological scale of the Pleistocene, Chtenie pamyati L. S. Berg, 1960-1966, Nauka Publ., 1968, pp. 17-64.

Zubakov V. A. Global climatic events of the Pleistocene, Moscow: Gidrometeoizdat, 1986, 288 p.

Zubakov V. A. Glacial-interglacial cycles of the Pleistocene of the Russian and Siberian plains in spore-pollen diagrams. Saint Petersburg: Publishing House of the State Hydrologist, Institute, 1992, 122 p.

Zykina, V. S., Structure of the loess-soil sequence and evolution of Pleistocene pedogenesis in Western Siberia, PhD dissertation abstract. Novosibirsk, 2006, 32 p. (in Russian)

Climate change. - L: Gidrometeoizdat, 1980. - 360 p.

History of Pleistocene lakes of the East European Plain. St. Petersburg: Nauka Publ., 1998, 406 p. (in Russian)

Klimanov V. A. Klimat Severnoi Evrazii v pozdnelednikovye i holocene (po palynologicheskim dannym) [Climate of Northern Eurasia in the Late Glacial and Holocene (based on palynological data)].

Loginova L. P., Makhnach N. A., Shalaboda V. L. Paleogeography of lakes in the south of the Minsk region / / Paleogeography of the Cenozoic of Belarus. Minsk: Nauka i tekhnika Publ., 1989, pp. 152-160.

Markov, K. K., On the multiplicity of glaciations (article one), Izv. AN SSSR. Ser. Geogr. i geofiz. - 1938. - N 2/3. - pp. 273-284.

Markov, K. K., On the content of the concepts of "glacial epoch" and "interglacial epoch", Izv. - 1939. - Vol. 71, N 7. - pp. 1071-1075.

Markov K. K. Paleogeography: (Historical Land Science). - 2nd ed., reprint-Moscow: Publishing House of Moscow State University, 1960. - 268 p.

Markov K. K. Dva ocherka o geografii [Two essays on Geography], Moscow: Mysl, 1978, 125 p.

Markov K. K., Velichko A. A., Lazukov G. I., Nikolaev V. A. Pleistocene. - Moscow: Higher School, 1968. - 304 p.

Maudina, M. I., Pisareva, V. V., and Velichkevich, F. Yu., Odintsovo stratotype in the light of new data, Dokl. ACADEMY OF SCIENCES OF THE USSR. - 1985. - Vol. 284, N 5. - pp. 1195-1199.

Makhnach N. A. Stages of vegetation development in Belarus in anthropogenic conditions. Minsk: Nauka i tekhnika Publ., 1971, 210 p. (in Russian)

Milankovich M. Matematicheskaya klimatologiya i astromicheskaya teoriya kolebaniya klimata [Mathematical climatology and astronomical theory of climate fluctuations]. science. - tech. publishing house, 1939. - 207 p.

Paleoclimates of the Holocene of the European territory of the USSR, Moscow: Publishing House of the Institute of Geography of the USSR Academy of Sciences, 1988, 195 p.

Paleoclimates of the Late Glacial and Holocene periods, Moscow: Nauka Publ., 1989, 168 p.

Sanko A. F., Valchik M. A., Elovicheva Ya. K., Arslanov Kh. A. Upper Pleistocene deposits of the Dvinsko-Mezhinskaya lowland // New in the study of Cenozoic deposits of Belarus and adjacent regions. Minsk: Nauka i tekhnika Publ., 1989, pp. 45-68.

Khotinsky N. A. Holocene of Northern Eurasia, Moscow: Nauka Publ., 1977, 198 p.

Sharaf Sh. G. Astronomical calendar / / Geochronology of the USSR, 1974, vol. 3: The newest Stage, pp. 258-266.

Shik, S. M., Climatic rhythmicity in the Pleistocene of the East European Platform, Stratigrafiya. Geological correlation. - 1993. - Vol. 1, N 4. - pp. 105-109.

Shik S. M. Problemy stratigrafii i paleogeografii srednego neopleistocene [Problems of stratigraphy and paleogeography of the Middle Pleistocene]. the second one. by phone. quarter of the period. Syktyvkar, 2005, pp. 459-460.

Shik, S. M., Borisov, B. A., and Zarrina, E. P., On the project of the interregional stratigraphic scheme of the Neo-Pleistocene of the East European Platform and the improvement of regional stratigraphic schemes,Mat. the second one. by phone. fourth. period. Smolensk, 2002, vol. 2, pp. 125-129.

Bassinot E. C., Labeyrie L. D., Vincent E., Quidelleur X., Shackleton N. J., Lancelot Y. The astronomical theory of climate and the age of the Brunhes-Matuyama magnetic reversal // Earth Planet. - Sci. Lett. 1994. - Vol. 126. - P. 91 - 108.

Bauch H. A., Erlenkeuser H., Helmke J. P., Struck U. Apaleoclimatic evaluation of marine oxygen isotope stage 11 in the high-northern Atlantic (Nordic seas) // Global and Planetary Change. - 2000. - N 24. - P. 27 - 39.

Beaulieu J. L. de, Reille M. Pollen records from the Velay craters: A review and correlation of the Holstainian interglacial with isotopic stage 11 // Mededelingen Rijks Geologische Dienst. - 1995. - N 52. - P. 59 - 70.

Bolikhovskaya N. S. Paleogeography and Stratigraphy of Valday (Wurm) Loesses of the South-Western Part of the East-European Plain by Palynological Data // Problems of Stratigraphy and Paleogeography of Loesses: Annales Universitatis M. Curie-Sklodowska. - Lublin, 1986. - Sect. B, XLI. - P. 111 - 124.

page 27

Bolikhovskaya N. S., Molodkov A. N. East-European loess-palaeosol sequences: Palynology, stratigraphy and correlation // Quaternary International. - 2006. - N 149. - P. 24 - 36.

Bowen D. Q., Richmond G. M., Fullerton D. S., Sibrava V., Fulton R. J., Velichko A. A. Correlation of Quaternary glaciations in the Northern Hemisphere. Quaternary glaciations in the Northern Hemisphere. Report of the IGCP project 24 // Quaternary Science Reviews. - 1986. - N 5. - P. 509 - 510.

Follieri M., Magri D., Sadori L. - 250,000-year pollen record from Valle di Castiglione (Roma) // Pollen and Spores. - 1988. - Vol. 30. - P. 329 - 356.

Hammen T. van der, Wijmstra T. A., Zagwijn W. H. The floral record of the Late Cenozoic of Europe // The Late Cenozoic Glacial Ages. - New Haven: Yale University Press, 1971. - P. 391 - 424.

Hodell D. A., Charles C. D., Ninnemann U. S. Comparison of interglacial stages in the South Atlantic sector of the southern ocean for the past 450 kyr: implications for Marine Isotope Stage (MIS) 11 // Global and Planetary Change. - 2000. - Vol. 24. - P. 7 - 26.

Jessen K., Milthers V. Stratigraphical and paleontological fresh-water deposits in Yutland and Northwest Germany // Danmarks Geologisk Undersogelse. - Kobenhavn: Kommission hos C. A. Reitzels Forlag Axel Sandal, 1928. - II Raekke, 48:1. - 380 p.

Jung W., Beug H. J., Dehm R. Das Riss-Wurm-Interglacial von Zeifen, Landkreis Laufen a. d. Salzach // Bayer. Akad. Wiss., Mat-Nat. Kl. Abh. NF. - 1972. - H. 151. - S. 3 - 131.

Liivrand E. Bio stratigraphy of the Pleistocene deposits in Estonia and correlations in the Baltic region: Doctoral thesis. Stockholm University, Department of Quaternary Research. - 1991. - Report 19. - 114 p.

McManus J. F. A great grand-daddy of ice cores // Nature. - 2004. - Vol. 429. - P. 611 - 612.

Molodkov A., Bolikhovskaya N. Eustatic sea-level and climate changes over the last 600 ka as derived from mollusc-based ESR-chronostratigraphy and pollen evidence in Northern Eurasia // Sedimentary Geology. - 2002. - Vol. 150. - P. 185 - 201.

Molodkov A. N., Bolikhovskaya N. S. Long-term palaeoenvironmental changes recorded in palynologically studied loess-palaeosol and ESR-dated marine deposits of Northern Eurasia: implication for sea-land correlation // Quaternary International. - 2006. - N 152/153. - P. 37 -47.

Reille M., Andrieu V., de Beaulieu J. -L., Guenet P., Goeury C. A long pollen record from Lac du Bouchet, Massif Central, France for the period 325 to 100 ka (OIS 9c to OIS 5e) // Quaternary Science Reviews. - 1998. - Vol. 17. - P. 1107 - 1123.

Reille M., de Beaulieu J. -L. Long Pleistocene pollen records from the Praclaux Crater, south-central France // Quaternary Research. - 1995. - Vol. 44 - P. 205 - 215.

Starkel L. Paleogeography of Md- and East Europe during the last cold stage with West European comparisons // Phil. Trans. Royal Soc. - 1977. - Vol. 280, N 972. - P. 351 - 372.

Tzedakis P. C. Long-term tree populations in northwest Greece through multiple Quaternary climatic cycles // Nature. - 1993. - Vol. 364. - P. 437 - 440.

Tzedakis P. C., Andrieu V., de Beaulieu J. -L., Birks H. J. B., Crowhurst S., Follieri M., Hooghiemstra H., Magri D., Reille M., Sadori L., Shackleton N. J., Wijmstra T. A Establishing a terrestrial chronological framework as a basis for biostratigraphical comparisons // Quaternary Science Reviews. - 2001. - Vol. 20. - P. 1583 - 1592.

Wijmstra T. A. Palynology of the first 30 metres of a 120 m deep section in Northern Greece // Acta Botanica Neerlandica. - 1969. - Vol. 18. - P. 511 - 527.

Wijmstra T. A., Groenhart M. С. Record of 700,000 years vegetational history in Eastern Macedonia (Greece) // Revista de la Acadevia Colombiana Ciencias Exactas, Fisicas y Naturales. - 1983. - Vol. 15. - P. 87 - 98.

Wijmstra T. A., Smit A. Palynology of the middle part (30 to 78 m) of the 120 m deep section in Northern Greece (Macedonia) // Acta Botanica Neerlandica. - 1976. - Vol. 25. - P. 297 - 312.

The article was submitted to the Editorial Board on 26.03.07.

page 28

© library.se

Permanent link to this publication:

https://library.se/m/articles/view/SPATIAL-AND-TEMPORAL-PATTERNS-OF-VEGETATION-AND-CLIMATE-DEVELOPMENT-IN-NORTHERN-EURASIA-IN-THE-NEO-PLEISTOCENE