E. P. Zazovskaya

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.

Endolithic pedogenesis and rock varnish on massive crystalline rocks in East Antarctica

Desert varnish and endolithic organisms are two widespread phenomena that have been studied in detail separately; their interaction and their genetic relationships have virtually escaped the attention of researchers. Both phenomena are of indubitable interest for pedology: endolithic organisms as an agent of soil formation and rock varnish as a probable product of pedogenesis. It is argued that the system of endolithic organisms, their functioning products, and the rock has all the features inherent to soils: the rock layer subjected to the influence of external abiogenic factors and living organisms dwelling in the rock and synthesizing and decomposing organic substances. The action of biogenic and abiogenic agents leads to the in situ transformation of the rock with the accumulation and removal of the products of this transformation and with the development of vertical heterogeneity in the form of microhorizons composing the soil microprofile. Instrumental measurements indicate that the carbon content in the endolithic horizons developed by biota in granitoid rocks of the Larsemann Hills oasis varies from 0.2 to 3.3%, the nitrogen content in these horizons varies from 0.02 to 0.47%, and the radiocarbon age of their organic matter reaches 480 ± 25 yrs. The products of the pedogenesis are represented by fine earth materials and by abundant and often multilayered films and coatings on the rock surface and on the lower sides of the desquamation (spalling) plates. Scanning electron microscopy with X-ray microprobe analysis indicates that the major elements composing these films are O, C, Si, Al, Fe, Ca, Mg, and S. It is shown that the films of the rock varnish and the organomineral films in the fissured zone of the rock under the plate with endolithic communities have certain similarity in their morphology and composition: the films of the rock varnish also contain biota (dead cells or cells in the dormant state), and their botryoidal structure is similar to the structure of the biofilms inside the endolithic system. In both types of films, amorphous aluminum and silicon compounds are present, and the accumulation of Fe, Ca, Mg, S, Cl, and some other elements takes place. It is argued that some varieties of rock varnish are the products of endolithic pedogenesis; in essence, they represent the horizons of micropaleosols exposed to the surface in the course of spalling and then transformed by the external environmental agents.

Mycological Characteristics of the Cultural Layer of a Medieval Settlement on Soddy Calcareous Soils

The difference between fungal communities in the cultural layer of a medieval settlement and in the background soddy calcareous soil is shown. In the cultural layer, the portion of spores, especially large spores (d > 6 μm), in the total fungal biomass is increased, whereas the portion of mycelium, especially with a thickness of > 4 μm, is decreased. The species composition of micromycetes in the cultural layer is also transformed; species from the Aspergillus and Fusarium genera predominate. The frequency and diversity of Penicillium representatives decreases, whereas the fungal species from the Phoma, Doratomyces, Geomyces, and Verticillium genera, which are not typical of the background soil horizons, increases. The diversity of the minor fungal species also increases in the cultural layer. An increased content of keratin-decomposing soil fungi is found in the cultural layer. It is argued that the use of the entire set of these characteristics makes it possible to perform mycological indication of the parts of the cultural layer that served different purposes (ancient streets, house floors, backing of the walls, etc.) within the settlement.

Absolute chronology of fluvial events in the Upper Dnieper River system and its palaeogeographic implications

A set of 121 radiocarbon and OSL dates has been compiled from the Upper Dnieper River and tributary valleys, Western European Russia. Each date was attributed according to geomorphic/sedimentological events and classes of fluvial activity. Summed probability density functions for each class were used to establish phases of increasing and reducing fluvial activity. The oldest detected reduction of fluvial activity was probably due to glacial damming at LGM. Within the Holocene three palaeohydrological epochs of millennial-scale were found: (1) high activity at 12,000–8,000 cal BP marked by large river palaeochannels; (2) low activity at 8,000–3,000 cal BP marked by formation of zonal-type soils on -floodplains; short episodes of high floods occurred between 6,500—4,400 cal BP; (3) contrasting hydrological oscillations since 3,000 cal BP with periods of high floods between 3,000–2,300 (2,000) and 900–100 cal BP separated by long interval of low floods 2,300 (2,000)-900 cal BP when floodplains were not inundated — zonal-type soils were developing and permanent settlements existed on floodplains. In the last millennium, four centennial-scale intervals were found: high flooding intervals are mid-11–mid-15th century and mid-17–mid-20th century. Intervals of flood activity similar to the present-day were: mid-15–mid-17th century and since mid-19th century till present. In the context of palaeohydrological changes, discussed are selected palaeogeographic issues such as: position of the glacial boundary at LGM, role of changing amounts of river runoff in the Black Sea level changes, floodplain occupation by Early Medieval population.

Fungal communities in the soils of early medieval settlements in the taiga zone

The difference between the mycobiota in anthropogenically transformed soils of the settlements of the 9th–14th centuries and in the background zonal Podzols and umbric Albeluvisols of the middle and southern taiga subzones in the European part of Russia is demonstrated. The mycological specificity of anthropogenically transformed soils with a cultural layer (CL) in comparison with the background soils is similar for all the studied objects. Its characteristic features are as follows: (1) the redistribution of the fungal biomass in the profile of anthropogenically transformed soils in comparison with zonal soils, (2) the lower amount of fungal mycelium in the CL with the accumulation of fungal spores in this layer, (3) the increased species diversity of fungal communities in the CL manifested by the greater morphological diversity of the spore pool and by the greater diversity of the fungi grown on nutrient media, (4) the change in the composition and species structure of fungal communities in the CL, (5) the replacement of dominant species typical of the zonal soils by eurytopic species, and (6) the significant difference between the fungal communities in the CL and in the above-and lower-lying horizons and buried soils of the same age. Most of the mycological properties of the soils of ancient settlements are also typical of modern urban soils. Thus, the mycological properties of soils can be considered informative carriers of soil memory about ancient anthropogenic impacts.

Soils of Queen Maud Land

This chapter describes the soils of Queen Maud Land (QML). This is the part of Antarctica between longitudes 20° W and 45° E. QML is the fourth largest ice-free territory of Antarctica, comprising 3,400 km2 (6.9 % of total ice-free area). The most studied areas of QML in terms of soils include the Sor Rondane Mountains and Schirmacher Oasis (35 km2). QML is underlain by continuous permafrost. The mountains are underlain by thick permafrost; and active layer ranges from 8 to 40 cm in depth to from 30 to 120 cm in depth in the Schirmacher Oasis. The dominant soil taxa include Typic Haploturbels-Haplorthels and Lithic Haploturbels-Haplorthels under moss cover, Typic Aquorthels Haplorthels in soils along lake margins and those influenced by algae, Typic Haploturbels in areas of patterned ground, Typic Haplorthels in dry areas, and Typic and Lithic Anhyorthels-Anhyturbels in the mountains. Soils of Queen Maud Land are less developed than those elsewhere in East Antarctica because they are more distant from the coast and have not been influenced by penguins and other birds.

Alteration of rocks by endolithic organisms is one of the pathways for the beginning of soils on Earth

Subaerial endolithic systems of the current extreme environments on Earth provide exclusive insight into emergence and development of soils in the Precambrian when due to various stresses on the surfaces of hard rocks the cryptic niches inside them were much more plausible habitats for organisms than epilithic ones. Using an actualistic approach we demonstrate that transformation of silicate rocks by endolithic organisms is one of the possible pathways for the beginning of soils on Earth. This process led to the formation of soil-like bodies on rocks in situ and contributed to the raise of complexity in subaerial geosystems. Endolithic systems of East Antarctica lack the noise from vascular plants and are among the best available natural models to explore organo-mineral interactions of a very old “phylogenetic age” (cyanobacteria-to-mineral, fungi-to-mineral, lichen-to-mineral). On the basis of our case study from East Antarctica we demonstrate that relatively simple endolithic systems of microbial and/or cryptogamic origin that exist and replicate on Earth over geological time scales employ the principles of organic matter stabilization strikingly similar to those known for modern full-scale soils of various climates.

Soil-like Patterns Inside the Rocks: Structure, Genesis, and Research Techniques

Microprofiles established due to the activity of endolithic communities inside the solid rocks of East Antarctica were studied with the approaches of soil science. Major products of endolithic rock transformation in situ are the silty-sandy fine earth and abundant organo-mineral films that are formed within the porous space of endolithic system. Such films are the result of interaction between biofilms and mineral surfaces and reflect elemental composition of both components, mainly comprising C, O, Si, Al, Fe, K, Ca, Na, and Mg. Morphology observed on different hierarchical levels and microtomography data indicated that different layers of endolithic system are connected with the fracture network serving for the elements transfer in the subsurface part of solid rocks. Examined profiles in granites with high quartz content had clear eluvial–illuvial differentiation patterns similar to macroprofile of a common Podzol (Spodsol) on loose substrates. It is shown, that subaerial segment of hard rocks is not sealed and is potentially permeable for dissolved products of endolithic weathering and pedogenesis. As a unique result—the soil-like pattern is established inside the massive, crystalline rock. Understanding modern processes in endolithic systems is of fundamental importance to decrypt paleosol record, as such systems may be the closest modern analogues of protosoils that existed on our planet before the higher vascular plants with root systems established.

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.