ИСТИНА

Soil micromorphology is increasingly in demand for studying archaeological sites and objects. Micromorphological studies of habitation deposits in order to reconstruct man-induced and natural on-site formation and transformation processes is the most common task for applied micromorphological studies in archaeology. In most cases soil micromorphologist is involved in very local studies related to a particular stratigraphic or planigraphic unit of habitation deposits, and especially to a leaving floors within ones. Compilation, generalization and synthesis of information on certain patterns of micromorphological features in habitation deposits of different age, cultural, economical, and natural environmental background (climate, geomorphology, hydrology, vegetation, soils), formed in different zones of land-use demands serious joint efforts now for further advance of micromorphological studies in archaeology. There is an attempt to compare results of micromorphological case studies conducted for five early medieval archaeological sites located in different background environments. Three of the settlements – Gnezdovo, Muromskij Gorodok and Malaya Ryazan’ – are located in European part of Russia, in the Central Russian Plain. Gnezdovo pre-urban center is situated in boreal, moderately continental, humid climate, in sub-zone of mixed forests. Muromskij Gorodok is located in a forest-steppe belt (Middle Volga region). The climate in the region is cool, temperate, moderately continental, semi-humid. The second site of our interest in the middle Volga region is Malaya Ryazan’ settlement, which is located in temperate, moderately continental semi-humid climate, under meadow steppe vegetation. Two other sites are located in the Center of Asia. Por-Bajyn Fortress is situated in South Siberia (Tyva Republic), Sayan-Tuva Highland, in mountainous ultracontinental, semiarid permafrost-affected conditions, on an island in shallow but extensive lake, under tall-grass steppe. The fortress was built, but it wasn’t actually ever settled. Jankent is a big fortified town located in the South Kazakastan, on Turan Lowland, in continental, arid climate, in a deserted, salt-affected area wiin ancient delta of Syrdaar’ya River. Each of these medieval settlements with the exception of Por-Bajin fortress is characterizes by generally differentiated spatialization of human impacts and a variable handicraft production. Micromorphological studies of habitation deposits revealed clear geographic and geochemic regularities in occurrence of features related to natural background soil processes. Intrasoil migration and accumulation of clay and coarser silicate material in textural pedofeatures were described in habitation deposits of mixed forest and forest-steppe belts (Gnezdovo and Muromskiy Gorodok). In the habitation deposits located in steppe landscapes with calcareous lithology (Malaya Ryazan’, Por-Bajin) key background soil process is redistribution and intrasoil accumulation of calcium carbonates. In desert environment major soil processes are accumulation of gypsum and readily soluble salts. All layers affected by overmoistening contain variable redoximorphic features depending on their palaeo- or/and contemporary water regime. Following anthropogenic features were identified in studied habitation deposit: 1). Features related to disturbance of natural soil (sediment) arrangement, stratification, distribution patterns resulted by turbation or removal of soil or sediment material, and newly formed anthropogenic stratification, layering distribution patterns; 2). features directly related to anthropogenic addition of material: rock microfragments, fragments of earth building materials and pottery, metal droplets; wood fragments, charcoals, and other plant residues; bones, coprolites of herbivores, fragments of mollusk and egg shells; 3). neoformed anthropogenic pedofeatures resulted from different chemical and physicochemical processes: phosphatic pedofeatures (coatings, infillings, nodules); calcitic phaecal spherulites, vitrified silica glass (melted phytoliths), calcareous ash. The set of anthropogenic features imprints past human impact in the locality: the higher a variety of athropogenic features and their general abundance, the more intensive and variable human impact occurred in the past. At the same time the occurrence of certain anthropogenic features may indicate not only human-related processes of their formation (introduction), but also a contemporary soil environment which can be favorable, or, in the opposite, deteriorative for ones. For instance calcareous features, such as phaecal spherulites, or egg shells are hardly can be preserved in the conditions of humid climate and active leaching processes; metal droplets certainly would be easily dissolved even in seasonally waterlogged environment. Thus the set of anthropogenic features revealing in a certain stratigraphic or planigraphic unit of habitation deposits is conditioned both by a type and intensity of local human impact and by local contemporary soil environment.