H. Achyuthan

Several terms have been used to understand the formation of highly indurated calcretes, such as hardpan, Stage VI calcretes and hardpan calcretes. In this paper, calcretes formed over the parent rock with distinct contact and underlying the aeolian/fluvial sediments have been termed as hardpan calcretes with no genetic connotations. They are important lithological units as they are forming a distinct element of the Quaternary landscape. These calcretes remain undated due to the paucity of dateable material and unsuitable dating methods. The purpose of this study is to determine the processes governing the development of hardpan calcretes and evaluate the local and regional controls on their formation.

The study area is located within the Nagaur-Churu-Jaipur tract. Hardpan calcretes have been mapped for their spatial extent and thickness over the bedrock both, in the field and using bore hole lithologs. They are nearly a meter thick formed over the bedrock with a sharp contact. Hardpan calcretes consists of 0.3 to 0.5 mm thick laminated carbonate zones forming rims around the detrital grains and nodules of calcium carbonate and siderite. They are distinct from the calcretes in aeolian dunes in being formed directly upon Precambrian bedrock and beneath 1 to 1.5 m of unconsolidated aeolian sand in low lying areas. They occur over the Precambrian hornblende -chlorite schist, rhyolite and carboneous phyllite. Along the Kataoti-Jayal tract, hardpan calcrete occur as boulders and gravel over the ferricretes of Late Neogene-Early Quaternary age. The calcretes around Narena, Churu, Talchappar, Ladnun Kataoti, Jayal, Didwana were studied in detail for their mineralogy, geochemical composition and stable isotope content. Micromorphology revealed thickening of calcite laminae downward and tapering at the sideward edges around the unweathered minerals of quartz and feldspars which indicate downward movement of carbonate solution and pore water. These solutions were probably derived from the upper horizons or surfaces bringing about the process of dissolution and recementation of individual laminae. Occurrence of fibrous attapulgite as coatings around the detrital grains and siderite (oolitic and pisolitic in shape) points to an subalkaline - subacidic process of pedogenesis. Attapulgite has formed due to the dissolution of silica grains. Lamination of calcite rim around the quartz grain indicates cumulative and compound pedogenesis, which probably occurred locally. Exfoliation of biotite grains in the primary calcium carbonate nodules is common. Spatial distribution, mineralogy and geochemical composition of the calcretes indicate that they have formed under poorly drained conditions probably within the capillary fringe in topographic lows. Stable isotope data of the hardpan calcrete laminae vary between -5.9l to -1.7l indicating their formation at - near surface (capillary fringe), probably supporting a thin column of soil. The source of most of the calcite was groundwater; however calcite nodule formation was largely dependent on pedogenic processes associated with evaporation, evapotranspiration and/or microenvironmental changes in pH and CO₂ partial pressure. However, dust is also a major source for the carbonate precipitation. It is commonly assumed that the powdery calcretes are younger in age compared to the more complex forms. However, occurrence of Middle Palaeolithic tools below the hardpan calcrete at Roopangarh and Dayalpura, and above the hardpan calcretes at Mitri, Genana and Rol, indicate that the morphology of calcretes is not a reliable indicator of age. Hardpan calcrete distribution is therefore, not merely a reflection of local topography but host material, sediment, time and rates of accretion, vegetation soil microenvironment and carbonate source.

A.L. Alexandrovsky¹, M.P. Glasko¹, S.N. Sedov³, N.A. Krenke², B.A. Folomeev², E.A. Kuznetsova²

The floodplains of rivers are characterised by a higher dynamics of all elements of landscape, including soils. During the Holocene the processes of river valley development, accumulation of alluvium, changes of flood levels and intensity resulted in periodical destruction of older soils and development of new ones.

In the floodplains of larger rivers as well as their smaller tributaries in the basins of Upper and Middle Volga, Oka, Moskva River, Upper Dnepr the sequences of buried soils were found. Their age, determined by ¹⁴C dating and archaeological findings, reaches 5000 – 6000 BP. Soils were formed during the periods of low floods, when alluvial sedimentation stopped. Numerous ¹⁴C and archaeological dates indicate the following intervals of intensive soil formation on the floodplains of Russian Plain: 6500-4500, 4000-3000, 2200-900 BP (non-calibrated age).

Because of progressive accumulation of alluvium many floodplains were not flooded any longer in the late, sometimes in the middle Holocene. In consequence soils of zonal types – Chernozems and Luvisols were formed on the floodplains. The periods of activisation of alluvial sedimentation, which resulted in the burial of soils, are induced by climatic changes, which occurred within the Holocene as well as increasing human impact. Deforestation and land cultivation in the river basins, which enhanced in the last 700 – 900 years, caused the increase of intensity and level of floods. Because of this on many floodplains of Central Russian Plain Luvisols (Grey Forest Soils and Albeluvisols) were buried under recent alluvium, on top of which weakly developed Fluvisols are formed.

L.A. Alexandrovsky, I.A. Matyukhina

Texture differentiated soils (TDS) (Luvisols, Albeluvisols) were formed in the Russian Plain soon after the beginning of development of the Holocene soil and plant cover. Before, during Valday (Würm) glaciation sedimentation and cryogenic processes hampered soil formation, especially development of TDS. Buried paleosols of the last glacial maximum and Pleistocene-Holocene transition, found within contemporary forest zone, are presented by weak humus or gleyic horizons often with cryogenic deformations.

There are indirect evidences that first TDS were formed already in the early Holocene. However weak leaching of parent materials and still active geomorphic processes constrained their development. Soils with humus-accumulative profiles were spread much more extensively.

In the Atlantic period mature TDS occupied vast areas in the Russian Plain. However the relict second humus horizons (SHH) in some TDS profiles indicate, that the boundaries between Chernozems, Grey Forest Soils (Eutric Luvisols) and Sod-Podzolic Soils (Albeluvisols) were located to the north of present position. ¹⁴C dates of SHH range from 8000 to 3000 BP the differences being related to the rate of reworking of humus of these horizons, which are often on shallow depth.

In Subboreal and Subatlantic periods with forest advancing towards steppe zone and tundra – towards forest zone the area of TDS grew considerably. In the profiles of TDS formed during this time SHH – the relicts of earlier pedogenesis – are present. SHH are better preserved in less drained positions and on more clayey parent materials. TDS which evolved from the middle Holocene humus-accumulative soils (Chernozems, Phaeozems) in the late Holocene do not differ from older TDS formed in persistent forest ecosystems regarding the degree of eluvial-illuvial differentiation.

We evaluated the rate of TDS development, studying soils on archaeological landsurfaces and river terraces of different age. Profiles without or with weak clay differentiation dominate on the landsurfaces with the age n´ 10 – n´ 100 years. However clay differentiation develops sometimes on such landsurfaces when formed by leached loamy sediments. We found well developed Luvisol profile on the 1000 years old rampart of settlement Rzhaventsi (basin of river Dnestr). On the 2500-4000 years old landsurfaces TDS do not differ considerably from surrounding soils regarding the degree of clay differentiation.

J. Berényi-Üveges, Z. Horváth, E. Michéli, A. Mindszenty, T. Németh

Besides field observations, mineralogical and chemical analyses, micromorphological and scanning electronmicroscope studies were carried out in order to reconstruct soil forming processes in paleosol profiles in an open lignite mine located in North Central Hungary (Visonta, pediment of the Mátra mountains).

Based on the results of the investigations, the recent soil and the paleosols have different parent materials and they were developed under different conditions. The present day soil is a Luvic Chernozem formed on calcareous loess. Under it, a red colored paleosol show evidences of both redeposition and in situ soil formation. The parent material is a weathered andesitic saprolite and red clays transported by mass movement to the pediment during the Pleistocene. In this epoch the Mátra mountains were intensively uplifted that enhanced the intensity of this process. The prismatic and wedge shaped structural units with stress cutans indicate Vertisol formation which is supported by the high clay content and smectitic mineralogy. Bioturbation in different scale, shrinking swelling, leaching, CaCO₃ and Fe-oxide precipitation, erosion-sedimentation, weathering, clay mineral formation and transformation, clay movement, organic matter accummulation, reduction and oxidation and frost action were processes showing evidences of changing environment during the formation of the sequence.

The Zahvizdja profile is exposed at 310 m a.s.l. in a large open pit of several working levels, in which loam is exploited for a brick-field. Zahvizdja is situated in the East Carpathian Foreland, in the catchment of the Bystrycja Solotvins’ka river – Carpathian tributary of the Dniester river. This profile is connected with a terrace surface rising about 80 m above the valley floor. This terrace was formed as a result of dissection of the planation level reaching 360-380 m a.s.l., which is called the Lojova surface (Villafranchien). It is the lower one of two planation levels found in the East Carpathian Foreland.

Erosion rock socle built of the Tortonian marine clays is covered with the Quaternary deposits 22 m thick, which consist of three main units: lower one (19.0-20.5 m) – alluvial gravelly-sandy-silty, middle one (14.5-19.0 m) – clayey-silty, and upper one (0.0-14.5 m) – loessy. Eight interglacial paleosols occur in the profile of the Quaternary deposits.

Especially interesting in this profile is the middle unit containing four soils of the intergalcial rank. All these soils are of forest type, gleyed, with distinct Bt horizons, and in places also the Eet and A horizons; the younger the soil, the more intensive gleying. In the whole unit the soils are made conspicuous by the occurrence of the following cryogenic deformational structures formed in the periglacial environment: pseudomorphs of segregated ground ice structures, ice wedge casts and diapiric convolutions – plastic density deformations of amplitude over 1 m, which disrupt the A and Eet horizons. They form a distinct polygonal pattern in the horizontal plane, which can be related to spotted tundra. The youngest soil was partially destructed by solifluction.

Therefore, in the discussed part of the Zahvizdja profile four warmings and four coolings were recorded. Warm phases were characterized by temperate, wet climate warmer than during the Mesopleistocene interglacials. Periglacial climate occurred in cold phases; signs of cooling became gradually more intense. We relate these climatic phases to the lower part of the Pleistocene.

Investigations are partially supported by Grant 6 PO4 E 031 15 from KBN.

A.Bronger¹, S.N.Sedov²

Terrae rossae (Rhodoxeralfs) derived from calcarenites of Mid-Quaternary age occur in the relatively moist Rabat-Casablanca area on the Atlantic coast of Morocco. They show considerable development of clay minerals, including disordered and poorly crystalline kaolinites, which have formed by weathering of primary feldspars and to a lesser extent smectites and other phyllosilicates in the calcarenites. Some profiles are pedocomplexes with clear evidence that soil formation was interrupted by deposition of eolian materials. The amounts of weatherable minerals in the C horizons are not sufficient to explain the increase of clay content in the B_t horizons by weathering in situ alone. However, there are two reasons why the increased clay content is also difficult to explain by illuviation. First, older well-developed argillans are rare in most of the terrae rossae. Argillans occur mainly as coats covering carbonates in some BC_k horizons on unstable surfaces. These would be the most recent generation of argillans, so we suggest that as the leaching front became deeper former illuviation argillans were destroyed by argillipedoturbation and bioturbation. Both processes are documented micromorphologically. Another problem is that eluvial horizons are mostly absent. This can be explained by soil erosion resulting from human activities (deforestation, over-grazing), which would also explain the patchy distribution of terrae rossae and the local occurrence of thick red (rubefied) pedosediments. In this area the effects of human activities have hitherto been under-estimated compared with Quaternary climatic change. Weathering and masking of argillans can therefore explain the clay content of these soils, including the presence of kaolinites in a typic xeric soil moisture regime, with a small moisture surplus in the first three months of the year. On the younger calcarenites (<100,000 years old) the soils are Rendzinas or weakly developed terrae rossae with only slight formation of clay minerals (mainly illites). Earlier workers have suggested that a mediterranean climate with only minor fluctuations (e.g. mean annual temperature in glacial stages was only 2-3 degrees C less than today's, and rainfall was only slightly greater) persisted in the Rabat-Casablanca area throughout the Quaternary. As the terrae rossae containing large amounts of clay (including some kaolinites) must have formed over a period of several hundred thousand years in this fairly uniform climate, they should be termed vetusols. We extend Cremaschi's (1987) definition of vetusol as follows: "a surface soil which has undergone the same or very similar processes of formation under the same constellation of soil-forming factors, especially climate, over a long period of time, including at least some part of the Pleistocene; the pedogenetic clay minerals differ quantitatively and qualitatively from those in nearby Holocene soils because of the much longer period of soil formation".

In southwestern Morocco between El-Jadida and Agadir the soil moisture regime is dry xeric to aridic and terrae rossae occur only in small areas, mostly in depressions. However, they show similar or even greater amounts of clay formation to those in the Rabat-Casablanca area, but contain little or no kaolinite. The weathering and clay illuviation must have been preceded by decalcification, implying a distinctly moister climate here in the past. However, micromorphological features of recent recalcification are common in these terrae rossae, suggesting that they are not in equilibrium with the present climate and must be regarded as non-buried paleosols (relict soils).

V.A. Demkin, T.S. Demkina

Paleosoil studying of about 250 archaeological monuments (kurgans) of Bronze, Early Iron and Middle Ages was carried out in steppes of the Lower Volga and South Ural. The objects under investigation include such places of kurgan groups as: "Abganerovo", "Aksai", "Bakhtiyarovka", "El'ton", "Petrunino" and others in Volgograd region, "Djangar", "Tsagan-Nur" in Kalmykiya, "Pokrovka" in Orenburg region. Dynamics of paleoecological conditions has been reconstructed for the last 50 centuries on a basis of comparative analysis made on the properties of burried paleosoils of different ages. It has been established that Bronze Age (III-II millennia BC) in Volga-Ural steppes was characterized by substantial variability of paleoenvironment. Relatively favorable climatic conditions of the 1st half of the III millennia BC changed on aridization. Its maximum was at the joint of the III-II millennia BC. At that time soil-geographical borders shifted to the North. Chestnut soils, in particular, evolutionized into the light chestnut ones; ordinary chernozems developed into the south chernozems etc. Mass appearance of the solonets soils was marked, as well as formation of complex soil cover was observed. Factual data revealed give grounds to consider Bronze Age as crisis from paleoecological viewpoint. In the 2^nd half of the II millennia BC moderation of continental climate with increasing atmospheric humidity occurred. This led to shift of natural borders to the South with formation of modern system of soil zonality.

The interval of existence of Srubnaya culture can be considered as the period of climatic optimum. Microbilogical data allow us to consider the paleoecological conditions of IV-III centuries BC as more auspicious in comparison to those of XIX-XVII centuries BC. At the same time the correlation of microorganisms, using easily available organic substance and humus is indicative of the growth of vegetation fall. The growth of phytomass can be explained by climate's humidisation. This process began in the second quarter of the II century BC in Low Volga steppe and reached its apex during the period of the Srubnaya culture communities. Early Iron Age (I millennia BC - IV century AD) was characterized by alternating of arid and relatively humid periods that did not result in noticeable shifts of the borders of natural zones. Nevertheless, Savromatian (VI-V centuries BC) and Late Sarmatian (II-IV centuries AD) periods were marked by more favorable paleoecological conditions as compared to Early and Middle Sarmatian time (IV century BC - I century AD). Following paleoecological data it was revealed first Medieval climatic optimum, dated to approximately XI-XIV centuries. It was noted by us in Volga-Don region, Zavolzh'e and South Ural. Increased atmospheric humidity at that period led to local shift of soil-geographical borders to the South. This natural process manifested itself most vividly on the territory of Ergeninskaya Upland (Lower Povolzh'e).

The work was supported by the Russian Foundation for Basic Researches and Federal Purpose Program "Integration".

C.G. Dlussky

The Oka river drainage basin (from 52°N to 56°N and from 36°E to 44°E) is situated in the northern part of the loess area on the East European Plain. The thick loess-like silt of Dnieper (Saale) age occurs below complete Upper Pleistocene loess-soil series in the region. The Middle Pleistocene fossil soils underlie the Dnieper loess-like silt. They compose a series which includes 3 paleosols close to each other: Romny interstadial soil, Upper and Lower Kamenka interglacial soils (by chronostratigraphic scheme published by Velichko et al., 1997).

The uppermost Middle Pleistocene fossil soil of this series is the Romny soil. The soil has weakly differentiated gleyed profile (A1G-G). Micromorphologically, there are the evidences of weak humus forming in its profile. The profile is heavily cracked and turbated by cryogenic deformations. Amongst the deformations, solifluction dominates in the north and west of region, but small polygon cracking dominated in the south and southeast of the region. The nearest modern analogues of this fossil soil are likely tundra gley cryomorphic and taiga gley-cryomorphic soils. Therefore it could be an interstadial soil.

The older fossil soil is Upper Kamenka one. The paleosol has bleached horizon only in the northernmost part of the region. On the rest territory, the paleosoil has a profile A1'-A1''-B_t-BC and can be compared with modern brunizems or meadow-chernozem soils. The following processes took part in its forming: active humus forming, active lessivage, sialitization and humus illuviation. In the north of the region humus forming was less intensive, but the role of eluvial-illuvial processes increased. The fossil soil can be compared with modern gray forest or pseudopodzolic soils in the north of the region. Upper and Lower Kamenka paleosoils were formed during two separate epochs of soil formation.

The oldest soil is Lower Kamenka one. It has bleached eluvial horizon over the whole territory of investigations (profile A1'-(A1'')-A2-B_tf(B_t)-BC(BC_g)). Leading soil-forming processes were pseudogley one with the participation of humus forming in the NW part of the region under study. The soils were similar to modern pseudogley (distric planosol). Lessivage, Fe- and humus illuviation took part in forming of the Lower Kamenka fossil soil in the central and southern parts of the region. Lessivage played the leading role and soils were similar to modern pseudopodzolic soils (lessive, luvisols) in many cases.

The study is a part of investigations carried out in the Laboratory of Evolutionary Geography IG RAS.

I. Fedeneva, M. Dergacheva

The evolution of the environment has been studied by now rather well for flat territories as concerns decoding its main laws as well as prediction of possible development of natural compounds in varying conditions. There with the ascertained regularities unfortunately cannot be extrapolated to mountainous areas where provincial and zonal distribution of the landscapes is complicated by the processes of vertical redistribution of heat and moisture, these processes have not been revealed to completion yet. Moreover, different exogenic processes developed in the mountains cause bad conservation of soil profiles that does not permit to use traditional methods of paleopedology to diagnosticate the conditions of ancient environment.

The approaches proposed in the present paper are based on:

Detail studying of late Pleistocene-Holocene paleosols and/or pedogenesis signs of different Gornyi Altai regions sediments permitted to reveal peculiarities of climatic fluctuations in depending on territories location. So, Central Altai was characterized with more continental climate than North-West Altai though amplitude of landscape conditions changes on the whole was close for different Altai regions.

Landscape changes in Central Altai didn't exceed the limits of dry steppe, from one side, and cryoarid steppe – from the other. There were no conditions for development of forest plant associations here in that period. In North-West Altai, on the contrary, forest associations often prevailed in landscapes. Here there were distinguished some stages of broad-leaved trees development, while in Central Altai their occurrence was limited by climatic continentality.

New approach permitted to suggest schematic map of the reconstructed mountainous landscapes of South-Eastern, Central and North-Western regions of the Altai Mountains not only for the main developmental stages of the environment throughout the past 130 thousand years, but also to reveal the special features within each of them. The periods of maximum glacial were found to be characterized by the simpler scheme of high-altitude sequence when cryoarid steppes expanded up to glacial border. At interglacial and interstadial periods the number of landscape zones is maximum and the structure of soil cover is more complex.

A. Golyeva, O. Chichagova

Modern and buried soils beneath gully sediments have been compared on the Southern Russian Plain (Kalmikiya) in the arid zone. This area is located 1500 km to the south of Moscow (45°41'N, 44°32'E). The modern climate is dry and warm. It has a mean annual temperature of 11.1°C and a mean annual precipitation of 350 mm. The modern surface soil (Molli-Endogleyic Solonetz), and three buried soils of different ages (1310 - 4260 BP) were studied. Age estimates were received by using ¹⁴C method of buried and modern soils. The radiocarbon dating, chemical and biomorph analyses were carried out. A chronosequence of soils development stages have been obtained. It became possible to reconstruct climate formation factors (first of all, the degrees of humidification and potential of soil fertility) from epoch of Bronze (4200 BP) up to the Middle ages (1300 BP).

All buried soils considerably differ from modern soil. They contain more humus and less carbonates, pH values are lower etc. The content and composition of humus in these soils is comparable with such modern soils as Haplic Kastanozems and Gleyic Phaeozems.

Each of buried soils has their own physical, chemical and biomorphological characteristics which differs from modern soil and allow to determine soil forming conditions and their evolution in time.

The comparison of differences in properties of buried soils at concrete time and historical data on cultures’ functioning in these periods has allowed to reveal interrelation of nature and society processes development in the South Kalmykia since middle Holocene. The following tendency is observed: the people settled on these lands during presence of the balanced nature-resource factors, and the lands were abandoned during the phases of environmental deterioration, desertification in particular.

O.S. Khokhlova¹, A.L. Alexandrovsky²

The kurgans (barrows) constructed by an ancient man and which are studied by the archaeologists nowadays are rather different objects. This is especially true for complex kurgans with a multi-layered mound and deep ditches constructed in different time using different ways and technologies. As the main aim of an archaeological study is to reconstruct an original construction of kurgan and technology used, understanding of natural processes changed this kurgan in course of its exposure can help. The natural scientific approach is taken to show by the example of the Big Ipatovsky kurgan (BIK). This kurgan was located on the left bank of the Kalaus river, near the Ipatovo city, Stavropol’ region, Russia. The first mound was constructed at >5000 BP on this site and then was overlaid by five other mounds in period of about two thousands years. Its height was about 7m in central bulk.

By the example of the BIK, the list of processes that are likely to change an artificial ground monument has been made. It includes erosional and colluvial processes, pedogenesis and diagenesis (change the mound after burial).

Any kurgan (mound together with ditch) creates a catena on the smooth steppe surface. The soils on the top of mound develop in conditions of lower quantity of water than the soils in the bottom of kurgan or in its ditch. As a result, the soils of the lowest part of this artificial catena are more humid with thicker and darker horizons and deeper of carbonates and gypsum than soils of the uppermost one. Sometimes the dark soil at the bottom of kurgan can mistake for a ditch whereas there is no ditch. Besides, the exposition of the slope plays an important role in redistribution of precipitation. Due to erosional and colluvial processes, the ground from the mound top is shifted to its bottom or ditch giving colluvial trains.

The oldest mound of the BIK has exposured on the surface for a relatively long period (about 500 years) and well processed by pedogenesis. The material of the mound was homogenous because of the burrowing animal's activity. The soil on top of the mound was weakly developed kastanozem, whereas soil buried under this mound was solonetz. The ditch of the first kurgan was rather shallow, and colluvium from the mound overlaid this ditch rapidly. Hence, the additional water began to wash soil out of the ditch and the thick dark zone of washing formed. The ditch of the second-third kurgans of the BIK was made at this zone and it was narrower and less deep than the zone. The mounds of the second-third kurgans were made one after the other and exposured in a relatively short period (some tens of years). On the tops of the mounds the primitive soils formed only with 3-4cm thickness of profiles. However, in the soil of the third mound the carbonates occurred from the surface whereas there were no carbonates in the profile of the second mound soil. The third soil probably formed at drier conditions than the second one.

The fourth mound was constructed using material of dark humic horizons of solonetz not from ditch but from vast surface cutting of the uppermost soil profile. The top of the fourth mound was horizontally levelled and overlaid by mixture of gypsum and carbonate horizons represented a natural cement that protected the mound from the environmental influence like a shell. Under this shell the fourth mound stayed inalterable, and fragments from different horizons of solonetz had different texture. The mixture of gypsum and carbonate has been taken from the deep pit, and knowledge of its property is evidence of the high technological level of ancient builders.

Inside of the fifth mound that laid on flat surface of the impervious shell the gleying processes occurred, and soil fragments without carbonates obtained a bluish gray color. Originally this color was considered by archaeologists studied BIK as a special technology used for the mound construction. All mounds and ditches of the BIK are enriched by diagenetic carbonates after burial. Diagenetic and soil carbonate accumulations differ in their morphology.

As a conclusion, studying the complex multi-layered kurgans we have to make out (1) different layers of mound and colluvial trains, (2) mound changed by pedogenesis and inalterable, (3) mound changed by diagenesis, (4) ditches and zones of washing. It can estimate duration of a kurgan exposure, rate of colluvial processes, climatic conditions at the period of different mounds existence.

P.V. Krasilnikov, N.A. Makarov

Dark organic layers are commonly reported for Medieval and earlier settlements all over Europe. They are generally believed to form due to mixing of organic wastes with soil material. These layers seems to be stable, as no chemical and morphological changes occur in them even from Mesolithic time (for 2-3 millennium).

We intended to investigate the composition and chemical properties of Mesolithic and Medieval dark layers in “Minino” rural settlement, where a series of dark layers have been detected. The settlement is situated on the bank of Kubinskoye lake, 150 km north-west from the town of Vologda, northern Russia. The objectives of the study were to compare the properties of dark layers of different age, to explain the difference, and to reconstruct the anthropogenic evolution of the soil.

The methods used in this study included micromorphological investigation, routine chemical analyses, and infra-red spectroscopy (IR), pyrolysis-surface ionization mass spectrometry (Py-SIMS), and electronic spin resonance (ESP) studies of organic matter.

The soil was formed on carbonate-rich lake sands with clay lenses. Albi-Calcic Luvisols and Calcaric Cambisols prevailed on the territory before human impact. The formation of anthropogenic dark layers has led to total transformation of soil profile. The Medieval dark layer is 40 cm in depth, and the Mesolithic dark layer is down to 95 cm in depth.

Both Mesolithic and Medieval layers are dark (N 2/ moist), and the organic matter consists of diffuse small particles, which form s-matrix and coatings on mineral grains. In both layers bones are abundant. The quantity of bones decreases with depth. Micromorphological observations showed a significant difference in the amount of organic matter in Mesolithic and Medieval layers. The results are supported by chemical data: the Mesolithic layer contains 0.3-1.6% of organic carbon, and the Medieval layer contains 3.8% of organic carbon, with a maximum of 9.1% on the surface. High organic matter content on the surface should be ascribed to a recent effect of organic fertilisers. All the dark layers, except the recently cultivated horizon, have slightly alkaline reaction (pH 7.1-7.4) and high content of exchangeable bases (28-41 and 13-23 cmol(⁺)´ kg^-1 in the Medieval and Mesolithic layers, respectively).

A thin layer was detected between the Medieval and Mesolithic ones. It was similar in macromorphology and chemical properties with the Medieval layer. A hypothesis that natural grassland vegetation formed between the Mesolithic and Medieval stages was supported by the micromorphological data: the organic matter was different from the down and upper layers. It formed globular aggregates typical for soils of northern grasslands.

The studies of organic matter showed that both dark layers contained much less aliphatic compounds in humic substances than natural and modern cultivated soils. The amount of aromatic compounds generally increased with depth. The phenomena can be ascribed to the decomposition of mainly aliphatic compounds.

The analysis of the results leads to the following conclusions.

Dark layers formed in Mesolithic time and Middle ages due to accumulation of anthropogenic wastes and their mixing with soil material. The rate of accumulation for a medieval rural settlement in Northern Russia is approximately 40 cm per thousand years.

A “break” in dark layer accumulation can be detected using micromorphological methods: if grassland existed on dark layer, then the organic matter form typical globular structure.

The stability of dark layers is a result of accumulation of the most resistant aromatic components of humus. The difference in the content of organic matter in Mesolithic and Medieval layers can be ascribed both to lower wastes accumulation in Mesolithic time and to partial decomposition of organic matter.

E.A. Leohtiev², S.A. Sycheva¹, A.A. Uzyanov², O.A. Gerasimova³

The problem of correlation of the cultural layers of the settlements and buried soils is of great importance not only for the archeology, but also for the soil science. Cultural layers date the soils, reflecting the periods of lowering the sedimentation processes rate.

The object of the soil-archeological study is the unique monument - settlement complex "Esky", located in the flood plain of the Osen and Mologa rivers and Verestovo lake within Mologo-Sheksnin lowland. The monument includes the finds of the eight archeological cultures from the Mesolithic up to Middle Ages, as well as the evidences of the ancient ploughings.

The variability of the paleoecological conditions, caused by complex interconnection of the hydrological regimes of Mologa and Osen rivers and Verestovo lake at the background of the climatic changes and constant lowering of Mologa-Sheksna lowland in Holocene creates the prerequisites for the periodical development of the monument's territory and better conservation of the cultural layers and buried soils.

In Holocene deposits one to three soils were buried. On an elevated part of the superimposed flood plain of the Osen river's right bank a complicated soil-antropogenic group developed, composing syngenetic buried soil and some cultural layers, connected with the different horizons. The Mesolithic artifacts have been recovered from the parent rock (brown loam) and the base of B_tg horizon; they do not form a consistent layer, which is typical for this period and may be attributed to a considerable intensity of the flood plain and slope sedimentogenesis. Neolithic layers are related to the low part of the profile, and in lower flood plain of the Osen river they form a separate stratigraphic level, representing meadow anthropogenic soil. Younger cultural layers of the Bronze epoch, Early Copper epoch, and Medieval are also included in a group of the humus horizons of the syngenetic soil, buried under the young alluvium.

Near the left bank of the Osen river the cultural layers of Eneolithic and Copper epoch coincide with the continuous level of subboreal meadow-forest soil. Nearer to the flood plain spit at the rivers confluence the early Copper and Medieval layers also form the level of Subatlantic anthropogenic meadow-gley soil.

During the last 200 years modern sod-gley soil is formed on the young flood plain sediments.

Lu Shenggao

Red paleosols are considered to be consequence of paleo-humid and thermal climate in Quaternary and cover an extensive area in tropical and subtropical regions of China. Authors proposed that the characteristics and special distributions of red paleosols could provide insight into the environmental change in Quaternary, such as inferring paleoclimate and vegetation shift, intensity of neotection movement and paleogeography. Because iron oxide mineralogy of red paleosols is a reflection of change in climate environment, their mineral type assemblage, crystallinity and ion substitution are indicators of environmental condition during formation of red paleosols. This paper describes a study of the ferrimagnetic iron oxide of representive red palesols from subtropical region of China by using mineral magnetic measurements, X-ray diffractometry (XRD), electron microscopy and chemical selective dissolution.

Combined rock magnetism, X-ray diffraction, electric microscopy and chemical selective dissolution indicated that maghemite was the domain remance carrier in red paleosols, which is characterized by superparamagnetic (SP) and stable single domain (SSD) grains, suggested that the ferrimagnetic minerals of red paleosols be a pedogenic ferrimagnetic component. It was further proposed that formation of maghemite and hematite is a basic process of soil formation in tropical and subtropical regions. The allitization process of tropical and subtropical soils is also a formation process of hematite and maghemite. The difference in allitization process and stage is responsible for the difference of amount and crystalinity of hematite and maghemite in the soils. Measurement of magnetic property of soil is the most sensitive way of distinguishing iron oxide characteristization. In comparison with modern ferrisols in tropical and subtropical soils, the highly allitizated red paleosols produce greater concentrations of ultrafine maghemite and has larger magnetic susceptibility values. According to mineral magnetism of red paleosols, we infer that the red paleosols originate from high temperature and humid climate environment, and magnetic susceptibility of red paleosos may be used as an indicator of Quaternary climate. It was concluded that the magnetism characterization of red paleosols could be used to evaluate the environmental changes of Quaternary in tropical and subtropical regions.

T.D. Morozova

The communication is centered at fossil soils which were first reported in 1870s – 1880s, when a "humus loess" was described in the loess sequence of the East European Plain (K.M. Feofilaktov, P.Ya. Armashevsky, a.o.). K.D. Glinka found that the "deep-seated soil formations" (humus loess) are differentiated into genetic horizons which sometimes form a fully developed soil profile; so they are to be studied using the same methods as those applied to the recent soil study.

Fossil soils are indicators of past landscapes. Accuracy of paleopedological results and reliability of paleoenvironmental reconstructions based on paleosols depends primarily on correct determination of the latter. I.P.Gerasimov contributed significantly to the fossil soil studies; he emphasized the complex character of the formations which calls for specific approach because of diagenetic (pedometamorphic) changes. At present, we apply practically the same analytic methods both to recent and fossil soils, though preference is given to those which permit to identify leading diagnostic characteristics of soil profiles resistant to time factor and diagenesis.

Widely used in paleopedology methods is the micromorphologic method; W. Kubiena was first to apply is to fossil soils. The method allow to study individual details of soil profile, both those containing information on ancient soil forming processes and others, related to diagenesis in buried state (S.V. Gubin, L.A. Gugalinskaya, V.S. Zykina, Zh.N. Maiskaya, T.D. Morozova, G. Haase, N. Fedoroff, I. Lieberoth, A. Bronger, L. Smolikova, K. Konec ka-Berley, B. Van Vliet-Lanoe , a.o.).

Significant data were obtained from Humus matter studies in fossil soils (I.V. Tyurin, M.A. Glazovskaya, O.A. Chichagova, N.I. Glushankova, M.A. Dergacheva, a.o.). Various dating methods are assessed, such as ¹⁴C, paleomagnetic, thermoluminescent, etc.

(O.A. Chichagova, M.A. Pevzner, G. Hott, H. Scharperseel, F. Heller).

Much consideration is given to paleogeomorphic conditions, for example, when studying paleosoils in catenas (A.I. Tsatskin, a.o.).

At present, many "loessial" regions of Eurasia, North America and other continents have been covered by paleosol studies. As a milestone in the 20^th century soil science progress, one could note achievements in genetic diagnostics of fossil soils attributed to different (interglacial and interstadial) Pleistocene epochs of soil formation. Those results permit to determine natural climatic zone the fossil soil belongs to, and to identify special features of former perdogenesis, as well as define type (and more seldom – subtype) of paleosols.

A scientific base was developed for paleosol mapping. Maps of soils dated to various Pleistocene stages were compiled for the Ukrainian territory (M.F. Veklich, N.A. Sirenko, Zh.N. Matviishina). A.A. Velichko and T.D. Morozova (Laboratory of Evolutionary Geography, Institute of Geography RAS) compiled soil maps of Europe and later – of Northern Eurasia for the Mikulino (Eemian) Interglacial (125 ka BP), the Bryansk interval (32-24 ka BP), and others.

The team of the Laboratory of Evolutionary Geography headed by A.A. Velichko uses spatial paleosol reconstructions as models in order to assess modern soil response to changes in hydrothermal regime under the man-induced climatic warming; in particular such modes are applied to forecast of the moisture content in soils (A.A. Velichko, L.O. Karpachevsky, T.D. Morozova).

Data obtained by M.A.Glazovskaya suggest a great importance of paleosols as "carbon depots". According to the data, "the fossilized carbon exceeds that of modern soils by an order of magnitude". Based on those results, M.A. Glazovskaya estimated the carbon budget in the past. A.A. Velichko and T.D. Morozova condiered the humus resources dynamics at the extrema of the Late Pleistocene macrocycle (the interglacial 125 ka BP, LGM 18 ka BP, and the Atlantic optimum 6-5.5 ka BP).

Those are some of essential results of the paleopedology by the turn of the millenium. One may hope that the results would be elaborated in the course of further research due to new research techniques, new dating methods and expanding of investigations over new regions.

S.Palacios-Mayorga¹, S.N.Sedov¹, G.E.Vallejo¹, A.L.Anaya², A.Gomez-Pompa³

The Yucatecan Maya developed an advanced civilisation based on poorly known systems of intensive agriculture in a region with a seasonally dry tropical climate. The shallow Lithosols and Rendzinas of this region would have constrained agriculture because they contain little organic matter, fix phosphorus and lose other nutrients by rapid leaching. How could these people provide enough food to sustain for several centuries a greater population density than today's in both rural areas and urban centres? Some present-day Mayan communities still practice complex agriculture and agroforestry systems using various organic materials as fertilisers, and the ancient Mayan civilisations may have done the same rather than practice slash and burn agriculture. The soil cover of an ancient rural Mayan settlement (a complex series of rock alignments) in a wetland area of El Eden Ecological Reserve (northeast of the Yucatan Peninsula in the State of Quintana Roo, Mexico) was the subject of an interdisciplinary study. The reserve has two distinct ecological areas: swamps in temporarily flooded depressions, and dry tropical forest in higher areas. The dry forest areas have shallow soils poor in humus and nutrients. However, in the swamps there is a periphyton composed of filamentous and other algae, fungi, protozoa, bacteria and other micro-organisms, which is rich in phosphorus and nitrogen and could have been used by the ancient Mayans as a fertiliser. In a glasshouse experiment the periphyton had a positive effect on plant growth. We are currently looking for phytoliths or other residues of the periphyton in ancient agricultural soils of the area to confirm its use as a natural organic fertiliser by the ancient Mayan people.

Th. Poetsch

In the Mainz Basin, at the northern edge of the Upper Rhine Lowland, a loess-palaeosoil-sequence of the last (Wisconsinan or Würm) glaciation is found at the site of Mainz-Weisenau.

Three palaeosoils of early Würm interstadials, the so-called Moosbacher Humic Zones, are found, each separated by loess strata. We refer to them as Lower, Middle, and Upper Humic Zone, respectively.

The lower part of the Lower Humic Zone, the so-called mottled zone, features an irregular pattern of darker and more brightly couloured structural elements, ranging in size from a few millimeters to some centimeters. The dark elements are more densely packed than the brighter ones and have an slightly higher clay content. The clay of which they consist shows a dark color, probably due to extremely fine and evenly distributed organic matter. The brighter elements have a lower clay content, the clay lacks the dark color and the porosity of the matrix is higher.

The loess overlying the Lower Humic Zone is rich in carbonate with 20–25% approximately (estimation from thin-section observations). Many of the carbonates distributed in the matrix show characteristic forms which proof that they derive from destroyed root-tube fillings and carbonatic hypocoatings. These were destroyed and mixed into the soil matrix due to loess redeposition and, partially, vertical turbation.

The Middle Humic Zone has a moderate carbonate content only (estimated to be about 4–7%). Clay-sized and fine silt-sized Calcites, having been dissolved, are nearly absent. Calcites of bigger size show marks of corrosion.

This humic zone is the most distinctive one, showing dark-brown, humic components with high clay content, which surround the coarse particles and as well form small aggregates. The clay does not show any microscopically visible humus particles, though. To the contrary, humus particles are visible in the coarser part of the matrix, where occasionally even opaque coarse-silt-sized humus particles are found.

The Upper Humic Zone is characterized mainly by its high content in calcitic earthworm biospheroliths (about 25 biospheroliths in a 20 cm² thin-section). This, together with earthworm tubes and feacal aggregates, proves a high biologic activity during this interstadial.

This study proves the distinctive character of the Humic Zones within the younger pleistocene palaeosoils in the study area.

K. Pustovoitov,

Pedogenic carbonate pendants, or cutans, on coarse rock fragments are common in stony soils of arid, semi-arid and semi-humid regions and can occur in humid areas in soils from carbonate-rich parent materials. Over the last decade a number of works demonstrated a great potential of carbonate cutans as sources of pedological information and paleoenvironmental record.

Data on rates of accumulation of carbonate material on the undersides of clasts in soils could be important for several directions of (paleo)pedological work: investigation of intensity of carbonate illuviation, dating soils and individual stages of soil processes etc. However, the question of the speed of cutan formation, as such, has not been specially discussed yet. The goal of the present contribution is to make an attempt to summarize the few data available on the rates of growth in thickness of pedogenic carbonate cutans on clasts.

Carbonate accumulations on clasts, on average 5-15 cm in length, in soils of semi-arid to humid regions (Mediterranean, Central Europe, North-Eastern Siberia) were considered. To date the cutans archaeological and radiocarbon methods were applied. Evidences from the literature on carbonate pendants from other areas were also involved for comparison. The rates were calculated with a number of assumptions.

Most of the rate values, irrespective of the conditions of soil formation, fall within the range of first 2 mm/1000 years, although much higher rates, up to 10 mm/1000 years, are possible in specific cases. Closer consideration shows that at least three factors may be favourable for a relatively intensive cutan growth: 1. carbonate-rich parent material, 2. warm and semi-arid to semi-humid climate and 3. large-sized clasts on which carbonate accumulation takes place. In order to provide a more detailed quantitative picture of the growth rates of carbonate cutans and a better understanding of factors and processes controlling them, much more studies over a wide range of conditions of pedogenesis should be made.

G.V. Rusanova

Characteristics of pedorelicts in lower parts of profile are used to discern polygenetic events. Soil micromorphology offers a way to distinguish the record of polygenesis in situations where differences in soil characteristics resulting from past climatic change are subtle or where that record has been obscured by regressive pedogenesis. On the Vorkuta region of Bolschezemelskaya Tundra, black humus pedorelicts in B horizon (50-55 cm) of Gelic Gleysols (depth of permafrost — 1.5-2 m) occur. These preserved relict features reflect former environment. The purpose was to use micromorphological techniques to test the hypothesis that soils of northeastern Europe experienced cycles of the Atlantic soil formation. Paleobotanic results and radiocarbon data, obtained for peat layers at 50-70 cm depth near the Vorkuta (Krasovskaya, 1995) permit to attribute the pedorelicts to the mid-Atlantic period of Holocene.

Micromorphological investigation of Gelic Gleysols showed the soil matrix appeared to have been subjected to cryogenic processes with the incorporation of organic fragments in distinct zones, weak to moderate expression of circular alignment of mineral grains and weak lenticular structure with horizontal layering suggesting ice lens formation. All of these features are common to soils that have been subject to freezing and thawing associated with a permafrost table and active layer.

The material of humus pedorelict is dark brown to black, isotropic or faintly birefringed, often flecked with black clots, with small plant residues and dark brown void argillans. These relict argillans are identified by their optical continuity, strong preferred orientation, lamellar appearance, and sharp boundary with the adjacent material.

The micromorphology of humus pedorelicts emphasizes the polygenic soil development resulting from the warm Holocene Optimum, with the average global temperature about 1° C above the present one when tundra soils persisted only on the Arctic ocean coast, and on islands.

F.Scarciglia¹, A.Cinque¹, C.Colombo², F.Terribile.³

The study area is located in Northern Cilento, which constitutes the southeastern margin of the Salerno Gulf (Campania Region, Southern Italy). It is a hilly promontory (Licosa Mt) reaching 326 m a.s.l., made of Tertiary flysch formations, mainly sandstones rich in quartz and feldspars with silty and clayey interlayers. The relief shows convex-concave cross profiles witnessing an evolution by slope replacement first and then by slope decline with the accumulation of detritic-colluvial taluses at the base. These are often made of coalescing detritic-alluvial fans, the last generation of which presumably was emplaced during the Last Glacial Maximum cold peaks, as its overlaying marine terraces of Euthyrrenian age suggests. Other various marine, transitional and continental Quaternary sediments fill the depressed zones and valleys of Licosa Mt (Cinque et al., 1994).

This area has a humid temperate Mediterranean climate typical of coastal zones. Mean temperatures vary from a minimum of 5 (in the month of January or February) to a maximum of 30°C (recorded in August); mean annual rainfall ranges between 800 and 1000 mm according to elevation and aspect (Lippmann-Provansal, 1987).

The attempt of this work has been to use soil information, obtained from selected paleosols, in order to interpret geomorphological and stratigraphical records in terms of response to Late Quaternary climatic fluctuations and environmental changes.

Three soil profiles were chosen as representative of three different geomorphic contexts having different age ranging from upper Middle Pleistocene to Upper Pleistocene and till the present (two of the studied paleosols are surface soils).

All the profiles represent Alfisols (sensu Soil Taxonomy, 1998) which have been characterised by routine physical-chemical analyses, optical (OM) and scanning electron microscopy (SEM) on thin sections and X-ray diffraction techniques (XRD) both on clay and sand fractions; iron oxides were identified by differential X-ray diffraction analysis (DXRD) (Malucelli et al., 1999).

Several pedogenetic features indicate marked weathering processes in all the three profiles; nevertheless some differences in the degree of weathering are also present. The main weathering features are the following: a moderate to strong weathering of primary minerals (still quartz grains) showing preferential fracture lines and/or surface pitting; the reddening of the matrix (or of some of its portions) due to Fe-oxides/hydroxides segregations; the abundance of clay and silty-clay coatings and infillings in the pores; the conspicuous presence of Fe-Mn concentric concretions in some horizons; the development of angular blocky structure; the moderate optical anisotropism of the matrix with the development of localised anisotropic areas, lines and aureoles. All paleosols show a clay mineralogy formed mainly by illite and kaolinite minerals.

Some of the mentioned features can be clearly interpreted as evidence of a paleo-pedoclimatic regime contrasting with the present day condition.

The examined soils show a very complex policyclic soil development by the alternation of features which can be referred to very different pedogenetic environments. As for this topic micromorphology analysis has shown to be very promising, allowing to identify relevant features such as (I) the various generations of laminated clay and silty-clay coatings (different colours, texture, interference colours, extinction patterns) and (II) the various forms and types of Fe and Mn oxides features (segregations, concretions and coatings).

References:

S.N.Sedov, E.Solleiro-Rebolledo, J.Gama-Castro, E. Vallejo-Gomez and A. Gonzalez-Velazquez

Paleosols buried under recent volcanic deposits are common throughout the Transmexican Volcanic Belt (TMVB). We studied a sequence of seven pedocomplexes (PT1-PT7) near the Nevado de Toluca volcano. In this area the modern surface soils are Andosols formed under coniferous forest (Pinus, Abies). The buried soils have well-preserved humus horizons. Pedocomplexes PT2-PT4 are Andosols showing greater accumulations of humus and oxalate- and dithionite-extractable Fe, Al and Si than the modern surface soils. In the topsoils of PT2 and PT3 numerous cracks form coarse angular blocks. Radiocarbon dates for the humus in these horizons suggest formation in the time interval 42,000-11,000 BP. The lower pedocomplexes PT5-PT7 are Luvisols with well-developed argic horizons. No dates are available for these, but from the rate of formation of argic horizons we suggest that they represent an interval of n x 10,000 years before PT3 and PT4. The stratigraphic position of PT1, which lacks an Ah horizon and has a Bw horizon that is paler in color and contains less illuvial clay than the underlying pedocomplexes, suggests it is Holocene in age. It indicates a rather dry environment in part of the Holocene. The Andosols of PT2-PT4 represent the cold interval of OIS2 and probably developed in humid forested ecosystems. The greater accumulations of humus and extractable Fe, Al and Si compared to the modern surface soil suggest a moister climate or longer periods of development. Short dry intervals are suggested by the topsoil cracking in PT2 and PT3. The older Luvisols of PT5-PT7 also formed under forest, and are more strongly developed probably because they formed over longer periods of time. These results suggest that humid forest ecosystems persisted in Central Mexico for much of the late Pleistocene. This agrees with pollen sequences dominated by Pinus and Quercus from lake sediments in the same area. However, in adjacent regions of tropical Mesoamerica terrestrial and marine records indicate arid conditions during the Last Glacial Maximum. Our results support the suggestion of J.P. Bradbury (1997, Sources of glacial moisture in Mesoamerica. Quat. Int. 43/44, 97-110) that there were contrasting late Pleistocene paleoclimates east and west of longitude 95 degrees W.

M.I.Skripnikova¹, N.V.Lagutina²

Human-created agrolandscapes always modify natural environment. The study of the natural background of agrolandscapes is important for revealing the factors that might affect the sustainability of agrolandscapes. Ancient terrace complexes (ATCs) in the North Caucasus render us an excellent example of sustainable and highly productive agrolandscapes; their surface has been preserved virtually intact for several thousand years despite climatic fluctuations and heavy anthropogenic loads The relief created by terracing is very stable and even more tolerant to modern anthropogenic impacts than the natural relief of mountain slopes. The reasons of this stability have to be understood in order to recommend appropriate technologies of modern land development in the region. The results of investigation into the natural basis of sustainability of terrace complexes might of interest to paleogeographers, soil scientists, archeologists, and specialists in mountainous agriculture.

According to modern data, the construction of ATCs was confined to xerothermic climatic phases that were observed in the North Caucasus in the second half of the 2^nd millennium BC and in the 5^th–12^th centuries AD (Shnitnikov, 1962; Tushinskii, 1963). Warm and moderately climate of these epochs favored the agricultural development in mountainous regions of the North Caucasus. Heavy anthropogenic loads (high population density, overgrazing, settlement and road construction) during these periods led to considerable degradation of the soil cover of cuesta landscapes. There was an urgent need to preserve loose slope sediments and to protect them from further erosion. This was achieved via slope terracing. Artificially constructed terraces were widely used for agriculture and provided high and sustainable crop yields. Thus, ATCs were not only the means of agricultural production, but also the stabilizers of the relief in cuesta landscapes.

The study of the morphology of initial slopes (under the terraces) showed that the construction of every terrace was strictly adjusted to particular geomorphic conditions. Slope aspect, inclination, shape, and the composition of hard bedrock and loose sediments were taken into account while designing the terraces. The slopes are composed of alternating layers of relatively loose (unconsolidated sandstone) and hard (dolomitic limestone) rocks. This sequence predetermined the location of particular terrace steps. The terraces were made by cutting of a part of a loose layer to form a horizontal surface. Loose rock was laid in a levee directly above the outcropping of a below lying hard layer. These levees served as strengthened terrace edge. Such a construction prevented the destructive action of seasonal runoff and favored the accumulation of condensed water percolating from the fissures in the above-lying hard rock layer within the terrace. The amount of earth cut off from loose layers and redeposited in levees above hard layers differed depending on the slope degree. On moderately inclined slopes (up to 15°), earth excavation works prevailed; on steep slopes, the terraces were mainly created via the construction of levees. The terraces created on northern slopes were considerably larger in size and better strengthened than those on southern slopes.

Theoretically, the construction of slope terraces should improve the stability of slopes. However, in practice, the terraces constructed without the proper assessment of geomorphic peculiarities of natural slopes are often less stable than surrounding slopes. At present, slope terracing in the region is performed according to the general scheme that does not take into account local peculiarities. The use of heavy machines for this purpose aggravates the situation. Newly constructed terraces have a limited resource of stability. Even optimistic forecasts assume that their use will be possible for no more than 80 years. In this context, the use of the ancient experience in the design of sustainable terrace complexes might be very helpful.

The stages of construction and further evolution of ATCs can be represented in a graphic form using the "Surface" package. The morphology of slopes before terracing can be reconstructed from data on buried profiles and the composition and amount of redeposited surface material in different parts of a terrace. This method helps us to reveal optimum technologies of terrace construction in different geomorphic conditions and to apply them in the modern practice of slope terracing.

M.I. Skripnikova¹, E.R. Usmanova²

Excavations of the Lisakovsky burial complex related to the Andronovskaya culture exposed 87 burial constructions. Essential differences of the inside design of burial mounds with similar external appearance were revealed.

Ten of the excavated mounds did not contain burials. A distinguishing feature for this kind of mounds is a thick shell-like masonry found under the embankment. Stones were laid on the burned soil surface in several rows (50 cm high) and bound together with clay. Large bones of animals were found in masonries of a few mounds.

Burial mounds were subdivided into ordinarily constructed ones (69 burials) and intricately designed, the so-called Mounds of Chiefs (8 burials). Ordinary mounds were built much in the same pattern as any burial mounds related to steppe cultures of that period. They have low (about 30 cm) earth embankments over the burial pit. The embankment is covered with one or two layers of stones.

Mounds of Chiefs are big (1 m high and up to 40 m in diameter) and usually occupy top positions in the steppe landscape. Some of them are surrounded by moat also containing burials; others, by mounds without burials. The conclusion about a higher status of such burial mounds and people who were buried there is supported by a unique set of burial implements as well as by soil morphological and analytical data.

First, a grass cover was burned in a place supposed for the construction of a Mound of Chief. The walls of burial chamber were coated with loamy material and surrounded with a low (10–15 cm) bank of bright gray material. A possible source of the material was found in riverbank exposures not far from the site. Chamber infilling and embankment (70 cm high) consist of salt-rich clay (that was an original material of subsurface horizons of the soils buried under the mounds) and sandy material derived from the moat. A surface of the earth embankment is covered with big stones.

A number of soil and archaeological features definitely testify that these mounds had been built in several stages; for long periods, they functioned as a burial–temple complex. The constructions of burial places proper and the mounds above them related to different time periods. It is probable that the mounds were constructed after a cessation of burial–temple complex functioning or a change in its status.

A.M. Soler-Arechalde¹, J. Urrutia-Fucugauchi¹, S. N. Sedov², E. Solleiro-Rebolledo² and J. Gama-Castro²

The preliminary investigation of five stratigraphic exposures from the Nevado de Toluca, an extinct volcano within the Trans Mexican Volcanic Belt, were carried out. 1 to 4 m thick stratigraphic units were studied and, in total, 62 samples were obtained. Initial, temperature and frequence dependent susceptibility as well as IRM and ARM experiments were performed, in order to identify magnetic minerals and check their stability. The results indicate some well-defined stratigraphic horizons and variations in magnetic properties, which is related to pedogenic and climatic processes.

E.Solleiro-Rebolledo, J. Gama-Castro and S.N. Sedov

Soils with relict properties, formed over periods longer than the Holocene, occur on stable land surfaces throughout the Transmexican Volcanic Belt (TMVB), and provide details of late Quaternary ennvironmental change in central Mexico. Luvisols were studied on the Glacis de Buena Vista (1800-2200 metres a.s.l.), 85 km southwest of Mexico City, which has been dated to approximately 40,000 BP. Several argic horizons separated by weakly weathered pumice layers, form a pedocomplex of five soil units (PB1-PB5). The argic horizons have well-developed blocky or prismatic structure, thick clay coatings, ferrimanganiferous nodules and mottles. PB3 is an Albeluvisol with a bleached illuvial horizon showing distinct tonguing into the argic horizon. In the middle part of the Glacis up to seven fragipans (Tepetates), partly cemented with amorphous silica, underlie the Luvisol sequence. The Luvisols indicate a humid climate with a forested ecosystem over the area during the late Quaternary. This interpretation agrees with data from buried paleosols in the TMVB and with palynological records from lake sediments in Central Mexico. Intense cracking of the argic horizons suggests seasonal aridity. The fragipans are closely associated with the luvisols, and do not occur on more recent land surfaces, on which the Holocene soils are Andosols, Cambisols and Leptosols. The fragipans were probably formed by hydroconsolidation processes in the humid paleoenvironment, the silica for cementation resulting from weathering of volcanic ash in the overlying Luvisols.

S.A. Sycheva

Mezin loess-paleosol complex (LPC) is widely spreaded in Oka-Don plain. Its arrangement reflects complicated history which includes Mikulino or Salyn interglacial (Eemian accoring to European system), early interstadial phase (Krutitsa) of the Valdai (Weichsel) glaciation and a transitional phase of syngenetic soil and loess formation in periglacial conditions.

In Middle-Russian plain the Late Pleistocene paleosols are preserved only in buried depressions of Eemian paleo-relief because of intensive denudation during the last climate-erosion cycle. These soils are included in a complicated pedo-lithologic series: polygenetic pedocomplex of the next-to-last glaciation and following interstadial age and three soils related to early interstadial phases of the last glaciation separated by slope deposits.

A comparison of the Late Pleistocene LPC in Oka-Don plain and in Middle-Russian plain allows making following conclusions:

1. Soils and sediments of upland trans-accumulative landscapes reflect an alternation of landscape and soil evolution stages in glaciation-interglaciation cycles in more details.
2. Mezin LPC, which occurs in paleodepressions, includes soils of two stages; each had phased development. There are signs of change in a type of soil formation, cryogenic and erosion-accumulation processes observed.
3. Soil of Mikulino interglacial displays three stages of forest and forest-steppe pedogenesis and two lithogenic ones when erosional processes persisted.
4. Transition to the last glaciation was accompanied by catastrophic events: forest fires resulting in accelerated erosion of interstadial soils.
5. Krutitsa phase includes three pedogenic stages when meadow soils were formed (Kukuevskaya, Streletskaya and Alexandrovskaya), and three cryo-lithogenic stages when cryogenic and intensive geomorphic processes were re-established.
6. Mezin loess-paleosol complex passed through the whole cycle of development from loess to a doublephased polygenetic soil. Mezin LPC has a complicated but still unified profile in plains of North Eurasia. On uplands where accumulation is increased (in buried paleodepressions) this LPC forms thick pedo-lithological series with lower hierarchic rhythms reflected.

S.A. Sycheva, M.P. Glasko, O.A. Chichagova

For solving the ecological problems of the soil formation in the Russian plain in Holocene we summarized our own and literary data on the radiocarbon studies of the second humus horizon (SHH) of the autonomous soils and humus horizon of the buried slope, balka and flood plain soils of the forest-steppe. The southern boundary of the SHH occurrence on the Russian Plain is the area of the gray forest soils of the northern forest-steppe. Usually they occur near watershed slopes and upper parts of balka and valley slopes facing north and east. In the bottom and on slopes of the valley-balka systems Holocene pedocyclites are developed widely, such as complicated, periodically repeating combinations of the different rocks and soils of different age. ¹⁴C data of SHH regarded to the middle Holocene, more often to the Atlantic period, united within two intervals: 7040-6680 BP (6 dates) 5860-4890 BP (13 dates); more seldom to Subboreal: 4560-2930 BP (7 dates). Generalization of the ¹⁴C dating results of the Holocene pedocycles permits to underline 6 buried soils: pd7 (about 10200 BP), pd6 (8300-9360 BP), pd5 (7600-6600 BP), pd4 (5900-4720 BP), pd3 (4200-3000 BP), pd2 (2370-1050 BP) and actual pdl (younger than 200 years). More often Atlantic soils are met: pd5 (25 dates), pd4 (21 dates), Subboreal (24 dates) and Subatlantic (18 dates); more seldom preboreal and boreal soils ate met. In the dividing intervals, as a rule ¹⁴C dates from deluvium, alluvial fan deposits and alluvium are fixed. The combination of the soil and morpholithogenic phases reflects the centuries-old rhythm of the landscape's development. The dominating number of ¹⁴C dates of SHH, despite of the obvious rejuvenation falls on the pedogenic phases and only 6 on morpholithogenic phases of the rhythm. It is obvious, that both SHH and the buried soils reflect the periods with the similar ecological conditions, which are more warm and comparatively dry. While in comparatively cold and humid Holocene phases happened the soil's degradation of watersheds and slopes and SHH isolation in the profile. In the accumulative landscapes different deposits were accumulated. Time of ¹⁴C dates of SHH mainly to the Atlantic period testify the considerable transferring of the soil to the North at that time (on one-two subzones). Warming of such degree (not only due to the temperature increase, but also due to their duration) twice occurred in the Atlantic period. In Subboreal and more over in Subatlantic periods they were, probably, less considerable and durable and that's why haven't reflection in the soil's structure of the autonomous landscapes.

B. Terhorst¹, F. Ottner²

Sequences of paleosols on glacial and fluvioglacial sediments have been studied near the south-west margin of the lake Lago Maggiore in the southern alpine foreland of Italy. In the Verbano Amphitheatre there is a series of morainic ridges composed of sediments of the Allogroup di Morazzone, which corresponds to the Mindel glaciation of the classical alpine stratigraphy. During subsequent glaciations the area was not covered by ice, but the land surface was modified by periglacial processes during cold stages and pedogenesis during warmer periods. The soils developed over this long period are polycyclic Luvisols forming very complicated pedocomplexes characterised by intense clay illuviation and strongly developed gley features. The aims of our study were to see whether these features could be used to date the sediments and correlate them with successions on the northern alpine foreland. Field surveys showed that the pedocomplexes consist of up to six different B_t horizons. We discuss micromorphological, clay mineralogical and magnetic susceptibility results for two of these pedocomplexes.

A.A. Velichko, T.D. Morozova, V.P. Nechaev

Relict cryogenic morphosculpture (RCM) was first identified within the limits of the former periglacial zone of The East European Plain (Velichko, 1964, 1965, a.o.); it is of primary importance in gaining insight into evolution of many components of geosystems in the modern forest and forest-steppe zones.

As follows from paleogeographic data, modern geosystems in the central part of the East European Plain began to form under still rigorous climate of the Late Pleistocene; at that time the plain north of 47-48° N belonged to the permafrost area with widely spread ice wedges. At the beginning of the Holocene, with climate warming, the ice veins began to melt, and former cryolithozone left its imprint on the present surface – relict cryogenic microrelief – in many regions of the plain.

Integrated paleocryogenic, pedologic and other studies show that the relict cryogenic microrelief has been acting as the principal factor of minute differentiation of soils throughout of the Holocene. There was found a correlation between the paleorelief and spatial variability of the soil agrochemical properties. Under conditions of warm and humid Holocene climate, the relict cryogenic microrelief influences considerably the onset of small erosional landforms on vast watersheds and in river valleys; this factor is to be taken into account when estimating potential erosional hazard.

V.S. Zykina

West Siberia is a region especially advantageous to study recent climate change, as its records are stored in widely distributed Quaternary deposits that are well documented in terms of paleontology and offer representative collections of samples for dating, thus providing a solid stratigraphic background. Moreover, the West Siberian Plain, extended west-easterly in moderate latitudes, exhibits a distinct north-southerly graded succession of climate zones. The most complete signature of global change during the Quaternary can be found in loess-soil sequences. An analysis of Pleistocene loess sections showed well pronounced trends in the evolution of climates and soils of warming stages reflected in the structure and types of soil horizons.

Early Pleistocene soil formation in southern West Siberia occurred in hydromorphic or half-hydromorphic conditions favored by smooth topography, near-surface position of groundwaters, and lithologically "heavy" underlying source rocks. The soils of that time are dense, clayey grassland and grassland chernozem varieties, subject to humus and clay accumulation, gleying, R₂O₃ enrichment, or locally to lessivage. In the middle Pleistocene, mostly automorphic polygenetic soils formed from porous loess-like sandy loam in the conditions of a more rugged relief. In the first half of each warming stage, the soils were involved in active lessivage and podzolization evident in illuvial clayey horizons. The final stage of soil formation was associated with intense humus accumulation. The post-Kazantsevo Late Pleistocene stages of soil formation were shorter and the warming was less strong. The chernozem-like and grey-forest-like soils of that time contain twice as thin humus horizons and less abundant clays, and have weakly differentiated profiles. Humus accumulation and carbonatization processes developed at high rates, while podzolization was weak. The soils that formed during the warming stages throughout the Pleistocene were mostly of Subboreal or less often Boreal types.

The intense soil formation during the early and middle Pleistocene, including the Kazantsevo interglacial, occurred in long stages under a moderately warm climate that remained warm and humid till the Late Pleistocene, and since then the climate changes became weaker but more frequent. The warming stages of Early Zyrianian and Karginian time were shorter and less contrasting, and the climate was cooler and more arid than before. In spite of being slightly colder than the previous Kazantsevo interglacial, the Holocene interglacial was much longer and warmer than those of Early Zyrianian and Karginian time. Since the Holocene, the trend of Late Cenozoic climate change has turned to general warming.