The paper presents results of a detailed subdivision of Holocene sediments in the region of the Kuban River delta into climate-stratigraphic units and reconstructions of the vegetation, climate and depositional environment changes on the Taman Peninsula (NE Black Sea region) during the last 7400 years. The reconstructions are based on data from geological-geomorphological and lithological-facies analysis, palynological studies and radiocarbon dating of six sections penetrated by boreholes in various parts of the Kuban River delta. The studied lithological sequences present an assortment of liman, fluvial, lacustrine and marsh sediments, as well as subaerial deposits that accumulated in the course of the delta development. The factual materials thus obtained provided the basis for reconstructing changes in zonal vegetation types and transformations of zonal and intra-zonal formations in the Holocene landscapes of the Taman Peninsula, induced by changes in edaphic conditions and regional climate. Seventeen phases (stages) have been recognized in the evolution of vegetation and climate through the Middle and Late Holocene, and a detailed description is given to every phase. A detailed pollen-climate-chronostratigraphic scheme of the Black Sea level fluctuations over the last 7400 years is proposed. Steppe and forest-steppe landscapes were dominant on the Taman Peninsula over the greater part of the studied period of the Holocene. The warmest and most arid conditions were typical of the phases dominated by steppes with grass, herb and grass, and pigweed-wormwood (Chenopodiaceae-Artemisia) plant communities. Such phases were dated to intervals similar to 4660-4400, 3780-3430, 2910-2280, 1540-1230 and 900-830/730 cal yr BP. The most humid intervals within the studied period are dated at similar to 5160-4900, 4400-3780, 2280-1540 cal yr BP. They were distinct because of the dominance of broadleaf (mostly beech-oak-hornbeam) forests. Those humid intervals most likely correspond to the maxima of the Kalamitian, Dzemetinian, and Nimphaean Black Sea transgressions. The climatic indexes and zonal attribution of the dominant plant communities can be matched with six transgressive and seven regressive sea level fluctuations of various ranks over the last 7400 years. Of the six transgressive stages, one stage was marked by a relatively cool and humid climate, whereas five others occurred under warm and wet conditions. The regressive stages include four phases of relatively warm and dry climate and three periods of dry and relatively cold (or cool) climate. (c) 2017 Elsevier Ltd and INQUA. All rights reserved.

The paper presents the results of a high-resolution palynological, paleomagnetic, and microtheriological study of the Pleistocene sediment sequence at Otkaznoye in the Eastern Ciscaucasian foreland; a sequence which is unique in its stratigraphic completeness and thickness (similar to 160 m). The sequence includes loess-paleosol, alluvial, and alluvial-proluvial beds. The detailed climatostratigraphic subdivision of the Otkaznoye sequence allows a correlation of the established paleoclimatic record with the global marine isotope stages. The past climatically induced variability in the landscape of the Terek-Kuma Lowland is reconstructed for all Neopleistocene (i.e., Middle and Late Pleistocene) interglacial and glacial periods and for some intervals during the later Early Pleistocene stages. (C) 2015 Elsevier Ltd and INQUA. All rights reserved.

The article deals with paleogeography and stratigraphy of the Pleistocene in the Terek-Kuma Lowland, a most arid region ofRussia(north-western part of the Caspian Lowland or the Eastern Cis-Caucasus). The results of detailed palinological, paleomagnetic and microteriologic examination of the Otkaznoye reference sequence (theMiddleKumaRivervalley) are for the first time analyzed in an integrated manner. The reference sequence composed of loess-soil, alluvial and proluvial-alluvial strata is unique in its depth (about160 m) and stratigraphical completeness. As a result of its detailed climatic-stratigraphic subdivision the paleoclimatic stages were reconstructed and correlated with marine isotope stages. Climate and landscape changes and successions of plant formations within the Terek-Kuma Lowland during all ice ages and interglacial periods of the Middle and Late Pleistocene, as well as several stages of the Early Pleistocene, are described. The results of detailed palinological analysis of a deepest loess-soil sequence in Northern Eurasia, the reconstruction of landscape-climatic conditions of soil formation and loess accumulation during the Pleistocene and the climatic-stratigraphic schemes have no analogues in foreign scientific publications dealing with paleogeography and stratigraphy of loesssoil strata in loess areas of North and South America, Western and central Europe, Central Asia and China.

The Matuyama/Brunhes boundary (MBB) in loess sections of the East European Plain, one of the greatest areas of global loess distribution, is a highly debatable issue. The ambiguity of the MBB position here results from the complexity of loess/soil magnetization processes and an apparent delay in loess remanence acquisition, and from the uncertainties of pedostratigraphic interpretations. In the Don Glaciation area, the MBB is unanimously placed below the Don moraine, although the exact position is still controversial. In the sites of the Northern Azov Sea, the MBB is, however, placed in the loess horizon considered to be the equivalent of the Don moraine in the north. The inconsistency of this interpretation is demonstrated by detailed magnetostratigraphic and pedostratigraphic studies in the western sites of Zaporozh'e (Dnieper basin), Novaya Etuliya (Lower Danube basin) and Roxolany (Lower Dniester basin). In all these sites, albeit with certain minor discrepancies, the MBB is found two or three interglacial palaeosols below the Don loess, which is overlain by the good stratigraphic marker of the Vorona pedocomplex, a thick polygenetic red-brown palaeosol formed supposedly in a Mediterranean climate. Here the MBB is placed in a ‘quadruple soil’ unit, termed “Roxolany loess/soil suite”, which consists of four closely spaced, strongly calcareous soils occupying an interval between the Don loess on top and the earlier well-developed Bobrov (?) loess with reversed Matuyama magnetization. The Roxolany suite can possibly be correlated with the three palaeosols of the pre-Don Ilyinka unit of the Russian Unified Stratigraphic Scheme and thus confirms the interpretation of the MBB in the central areas of the East European Plain as to the interval between the Ternovka (second-pre-Don) palaeosol and the Troitsk (third pre-Don) palaeosol.

Loess/paleosol sequences in the western Black sea area at Roxolany (48 m thick) and Novaya Etuliya (30 m thick) were studied using paleo- and rock-magnetic methods in conjunction with micromorphology and Mössbauer investigations. Although seemingly complete, the sites show variability in the type and number of loess/paleosol cycles, and inconsistency of the Matuyama/Brunhes boundary (MBB) stratigraphic position. At Roxolany, nine pedocomplexes (PK) and several incipient paleosols, alternating with thick loesses, were observed with the MBB being located between PK6 and PK7. At Novaya Etuliya, 13 PKs occur upon terrace XII with Khapry fauna and with the MBB in the upper part of PK7 and the Jaramillo subchron within the lower part of PK8. The depth functions of rock magnetic properties, organic carbon content Corg, both for bulk samples and for clay extracts, along with micromorphology and Mössbauer spectra, allowed objective identification of individual soils within PKs, and maximizing the resolution of paleopedological reconstructions of global climatic stages. The Mössbauer studies demonstrate that paleosols are basically enriched in ferric montmorillonite. Oxidized magnetite, ultrafine iron hydroxides and hematite are intimately associated with clay minerals. In contrast, Fe-compounds in loess consist mainly of ferrous silicates. These data indicate that the paleosol magnetism is basically of bio-chemogenic origin and is related to pedogenic transformation of Fe-compounds in a changing environment, while loess magnetism is primarily detrital. Pedogenic magnetically "soft" and partly oxidized magnetite may also originate during or even after burial. This ensuing transformation of Fe minerals in paleosols seems to be crucial for the understanding of the timing of natural remanent magnetization (NRM) in subaerial sediments. Given that paleosols formed on the similar parent material (loess), their typological variability seems to depend on climate and/or chronology. Hence, the different paleosol types from Roxolany and Novaya Etuliya provide key information for intra- and inter-regional correlation of loess/soil sequences, and represent valid paleoclimatic proxies.

The signature of the loess signal in magnetic properties of loess deposits is analyzed. This factor is shown to have a great effect on the hysteretic characteristics, and its disregard can lead to errors in determinations of the composition and size of remanence carrier grains. In addition, the paramagnetic signal can provide constraints on landscape-climate changes in the past.

A refined pedostratigraphic scheme in the western Black sea region is proposed on the basis of paleopedological reconstructions coupled with magnetic susceptibility, and other rock magnetic parameters, and Mössbauer spectroscopy. The new scheme matches well with oxygen isotope stages despite local variations in erosion/deposition, strong welding of paleosols and subtle discrepancies in the position of the Matuyama/Brunhes boundary. These limitations are reduced by optimizing resolution of magnetic cycles and paleosol identification. Two humid/warm maxima during the Quaternary are found in pedocomplex PK4 at about 0.5 Ma (corresponding to oxygen isotope stages 13 and 15), and in pedocomplex PK8 related to the Jaramillo subchron. Comparison with the oxygen isotope curve shows that the apparent major driving force of regional soil/loess cyclicity is the 100 ka eccentricity period.

Typical loess-palaeosol formations in the southern part of the Russian plain (Novaya Etuliya type section), in China and in Central Asia show the same pattern of magnetic susceptibility (MS) variations with enhanced signatures in soils compared to loesses. This behavior is well known to be caused by in situ forming fine grained magnetite (maghemite) of pedogenic origin. A different pattern of MS changes has been reported for Western Siberia and Alaska: high magnetic signatures in loesses and low ones in palaeosols. The highest MS values in the Belovo type section (Ob River) are connected with the sand and silt fractions and hence are due to sedimentary processes and terrigenous magnetic minerals. Low MS in palaeosols is related to gleisation. A more complex behaviour of ms changes is observed in the Precaucasus loess section at Otkaznoe. The palaeosols here show enhanced magnetic signatures whereas the loess horizons display largely variable magnetic signals due to changing detrital material influx.

Until now, palaeoclimatic reconstructions for the major stages in the development of the Quaternary loess-palaeosol sequence on the Russian Plain have been based on pedological, palynological and faunal (vertebrates and molluscs) analyses, in order to demonstrate the palaeoclimatic influence on the magnetic properties of this sequence, the magnetic susceptibility signature of the Strelitsa type section in the Upper Don basin is compared with a detailed landscape - climate reconstruction of loess and soil from palynological data. Large amplitude fluctuations of palaeoclimate and palaeoenvironment are reflected clearly in the lithology and in the rock magnetic properties, which usually are enhanced in wet and warm interglacial periods, but stay at low levels during cold glacial epochs. Palynological climate zonation, however, is sometimes in conflict with the pedologic-magnetic record. Strong climate fluctuations, as indicated by changing pollen assemblages, are not always paralleled by corresponding changes in lithology and/or rock magnetic properties. Alternatively, light coloured illuvial horizons with low magnetic signal sometimes appear to have formed during early stages of interglacials, and the top parts of some palaeosols apparently formed during glacial stages. Copyright (C) 2000 John Wiley & Sons, Ltd.