ИСТИНА

Paleopedological interpretations of archaeological data are often based on comparison of buried soils, adjacent surface soils and newly formed soils on burial mounds. Such comparisons presume, that a) buried soils were similar to soils formed beyond funeral area, so the differences observed now are the results of soil evolution; b) burial mounds were thrown up of soil material taken in immediate proximity to the mound, that also allow comparisons between soils on mound land surface and adjacent soils. Nevertheless, it is well known, that many ancient tribes were not indifferent to the type of soil material, and even specific soil horizons, and used very complicated construction techniques for burial mounds, governed by their religious and cosmological conceptions. So, material of specific sediment layers and soil horizons could be delivered from remote locations. Our study provides an example of such complicated techniques used for burial mound construction. Burial grounds (1500-2000 years before present) of Finno-Ugric tribes are widely distributed along Western Dvina, Velikaya, Lovat and other rivers in North-Western part of Russia and in Baltic States. The study area is located on late Pleistocene alluvial terrace of Western Dvina River. Natural soil cover is represented by weekly podzolised sandy soils (Cambisols), formed under pine forest vegetation. Burial ground comprises several dozens of mounds 2-7 m high, constructed with very complicated techniques. The analysis of mound structure showed that the burial procedures included the following stages: 1. Preparation of funeral area by removal of initial soil layer. 2. Laying a big funeral pile, resulted in formation of red-brown layer of burnt sand approximately 20 cm thick. 3. Filling the excavation with material of black humus horizons. 4. Distributing stones around the basement of a future mound. 5. Constructing of a mound by raising of well sorted sandy material, taken beyond the bounds of funeral area. 6. Mantling the mound surface with thick (40-50 cm) layer of carefully collected material of black humus horizons. Burial mounds were mostly used for repeated reinterments. As a result mound constructions include interlayering of sandy material with black lenses and layers. Usually two or three 10-12 cm thick black layers mantle the whole mound sub-parallel to temperate mound surface indicating several stages of burial and construction. Most of archaeological remains including cists, wooden remains of funeral boats, animal remains, stones, artifacts, etc., can be met within these black layers. Animal remains are often oriented, confirming the ritual meaning of their position. E.g. bear bones and claws are located in West and East corners and eagle bones and pounces - in the rest 4 corners of a hexagon. The source of black material used for construction is humus horizon of black meadow hydromorphic soils formed in the floodplains of small streams that flow into Western Dvina in the vicinity of several hundred meters – several km from funeral area. The study of black mantles on top of the mounds demonstrates no signs of their degradation under pine forest vegetation. Sand grains are covered with thick black films throughout the whole mantle. Humus content is 3-4%, though rough humus fractions, abundant in the source horizons of hydromorphic soils are absent in the mantle material. Therefore we may assume that mostly stable humus fractions remain and initial humus content could be even higher. Assessment of mound construction techniques demonstrates that: 1. Soils buried under the mound could be truncated and welded with artificial layers of humus horizons, and deeply influenced by burial pile. Consequently these soils do not represent adequately enough the natural soils of the time of mound construction. 2. Soil profiles on the day surface of burial mounds may consist of contrasting layers, which were initially stratified during construction and burial procedures and so do not adequately reflect soil evolution results. 3. Black humus sandy horizons show long term (millennium) sustainability under primary forest vegetation, illustrating that soil development during late Holocene mostly inherited soil features of previous stages. 4. Construction techniques of ancient tribes should be considered in paleosol studies of burial grounds. The architecture of burial mounds should be assessed by a whole set of archaeological, pedological and geological methods. Environmental reconstructions are possible only on the base of clear understanding of the sources and initial properties of materials used for mound construction.