O. A. Chichagova

The Catacomb Cultures of the North-West Caspian Steppe: 14C Chronology, Reservoir Effect, and Paleodiet

For the Bronze Age Catacomb cultures of the North-West Caspian steppe area in Russia, there is a conflict between the traditional relative archaeological chronology and the chronology based on radiocarbon dates. We show that this conflict can be explained largely by the fact that most dates have been obtained on human bone material and are subject to 14C reservoir effects. This was demonstrated by comparing paired 14C dates derived from human and terrestrial herbivore bone collagen. In addition, values of stable isotope ratios (d13C and d15N) and analysis of food remains from vessels and the stomach contents of buried individuals indicate that a large part of the diet of these cultures consisted of fish and mollusks, and we conclude that this is the source of the reservoir effect.

Paleoecology, Subsistence, and 14C Chronology of the Eurasian Caspian Steppe Bronze Age

Combined analysis of paleoenvironment, 13C, 15N, and 14C in bone, including paired dating of human bone and terrestrial materials (herbivore bone, wood, charcoal, and textile) has been performed on many samples excavated from Russian kurgan graves. The data can be used for dietary reconstruction, and reservoir corrections for 14C dating of human bone. The latter is essential for an accurate construction of chronologies for the Eneolithic and Bronze Age cultures of the Caspian steppes.

Radiocarbon age of Vertisols and its interpretation using data on gilgai complex in the North Caucasus

Radiocarbon dates were analyzed to assess Vertisols age around the world. They show an increase of radiocarbon age from mainly modern-3000 BP in 0-100 cm layer up to 10,000 BP at a depth 100-200 cm. Older dates reflect the age of parent material. The inversion of (super 14) C dates seems to be a frequent phenomenon in Vertisols. A series of new dates of Vertisols from gilgai microhigh, microslope and microlow in the North Caucasus was done in order to understand the nature of this inversion. (super 14) C age in the gilgai soil complex ranges from 70+ or -45 BP in the microlow to 5610+ or -180 BP in the microhigh. A trend of similar depths being younger in the microslope and microlow was found. We explain this by intensive humus rejuvenation in the microlows due to water downward flow. The older date in the microhigh represents the old humus horizon sheared laterally close to the surface and preserved by impermeable water regime. We explain inversions of (super 14) C age-depth curves by the sampling procedures. In a narrow pit, genetically different parts of former gilgai could easily be as a genetically uniform soil profile. Because of this strong microvariability, Vertisols require sampling in a trench accounting for gilgai elements, even when gilgai are not obvious.

The 14C age of humic substances in Paleosols

By comparing the radiocarbon age of the soils under burial mounds of known archaeological age with the surface-exposed (background) soils of the surrounding landscapes, we may evaluate the rates of humus renewal in these soils. In the cold climate of the mideastern areas of the Russian plains, the value of humus rejuvenation coefficient decreases. This shows that humus renewal is 5-10 times slower than in the warmer climate of the southern regions. Using the obtained data on the rejuvenation rate of humus substances, we can determine the age of paleosols and study the dynamics of the carbon exchange processes in the biosphere.

Palaeoecological evidence for Holocene vegetation, climate and land use change in the low Don basin and Kalmuk area, southern Russia

Two14C-dated pollen profiles from mires in the steppe belt of southern Russia are presented. On the basis of these and data from earlier investigations, the Holocene forest history of the southern part of Russia and Ukraine is reconstructed. The steppe belt is very sensitive to climatic oscillations and, in particular, to changes in evapotranspiration. The most favourable climate occurred between 6000 and 4500 B.P. (6800–5200 cal. B.P.), when forest attained its maximum extent in the steppe belt. The period 4500–3500 B.P. (5200–3800 cal. B.P.) was characterised by drier climate with the most arid phase occurring between 4200–3700 B.P. (4700–4000 cal. B.P.). During arid phases, the area under forest and also peat accumulation rates declined. Subsequently, a number of less pronounced climatic oscillations occurred such as in the period 3400/3300−2800 B.P. (3600/3500−2900 cal. B.P.) when there was a return to more humid conditions. During the last 2500 years, the vegetation cover of the steppe belt in southern Russia and Ukraine took on its present-day aspect. On the one hand, there is close correlation between the Holocene vegetation history of southern Russia and Ukraine and, on the other hand, the steppe belt of Kazakhstan and transgressions in the Caspian sea. Human impact on the natural vegetation became important from the Bronze Age onwards (after 4500 B.P.; 5200 cal. B.P.). Particular attention is given to the history of Scots pine (Pinus sylvestris), which had a much wider distribution in the southern part of eastern Europe in the early Holocene. The reduction in range during recent millennia has come about as a result of the combined effects of both climatic deterioration and increased human impact.

Paleosols buried under kurgans of the Pit-grave culture in the steppe zone of the Cis-Ural region

The analysis of soil chronosequences developed from loamy and loamy sandy substrates and buried under kurgans dating back to the Pit-grave archaeological culture in the steppe zone of the Cis-Ural region demonstrated that it is possible to trace the dynamics of the soil properties and to perform paleoclimatic reconstructions for different intervals within the studied period. The properties of sandy soils changed more rapidly than the properties of loamy soils. For sandy soils, notable changes in their properties were revealed in the soil chronosequences dating back to the particular stages of the Pit-grave culture; for loamy soils, such changes could only be traced for the soils buried under the kurgans dating back to different stages of the Pit-grave culture.

Radiocarbon chronology of the Kalmykia Catacomb culture of the west Eurasian steppe

New calibration studies of burials from the Catacomb culture of western Eurasia enable better understanding of the spread and development of different Bronze Age traditions.

Radiocarbon pollution and self-purification of humus in chernozems of the East-European plain in 1900–2008

The dynamics of the 14C content in the humus of chernozems in 1900–2008 are considered. The elevated 14C content in the atmosphere because of nuclear weapons tests has led to the contamination of humus with bomb radiocarbon. In 1966–1968, the 14C reserves in the profiles of chernozems exceeded the background ones by 15%; in 1978, by 12%; and, in 1998, by 2%. By the year of 2008, its reserves became equal to the background ones. The 14C distribution along the soil profiles changed. By 1978, the 0- to 30-cm-thick soil layer became free from radiocarbon due to its self-purification; however, at depths of 40–70 and 100–115 cm, its weak accumulation was registered. By 2008, the whole soil profile was free from 14C. The main mechanism of the soil self-purification from radiocarbon is suggested to be the constant substitution of fragments of humus compound structures for those of fresh organic matter entering the soils with the 14C content being in equilibrium with the atmospheric one, i.e., due to the renewal of the carbon in the humus. The rate of the carbon renewal and its migration in the soils are assed based on the 14C concentrations in the humus.

Buried paleosols in balks of Kalmykiya as a record of late Holocene nature and society interaction

Abstract Modern and buried soils under valley sediments have been compared on the Southern Russian Plain (Kalmykiya) in the arid zone. The buried soil contains more humus and less carbonates, and pH values are lower. The humus content in this soil is comparable with that of modern Haplic Kastanozems and Gleyic Phaeozems. The comparison of differences in properties of buried soil at specific times and historical data on cultures’ functioning in these periods has allowed us to reveal the interrelation of nature and society processes development in South Kalmykia since the middle Holocene. Three stages of landscape development are recognized: (1) stable stage, at least 3000 years long (from the 2nd millennium BC until the 1st millennium AD), characterized by the formation of meadow-steppe soils; (2) dynamic stage, likely short, when deposits were accumulated, and soils were buried; and (3) modern stable stage, at least 500 years long (up to the present time), characterized by the formation of meadow-saline soils (Molli-Endogleyic Solonetz) on deposits in valleys. A strong ecological crisis was evident in the territory of modern Kalmykia about 1000 years ago, resulting from the collapse of the Khazar state. As a result, meadow-steppe soils were buried, and Saline Molli-Endogleyic soils were formed.