Complex pedological analysis of paleosols buried under kurgans as a basis for periodization of the Timber-grave archaeological culture in the Southern Cis-Ural, Russia

Abstract

The problem of periodization of the Timber-grave culture of the Late Bronze Age on the territory of the Southern Cis-Ural is far from being solved. This situation exists because the funeral ceremony looks very similar throughout the history of the Timber-grave culture existence. To assign stages of this culture's development, a complex approach was used, including archaeological observation, radiocarbon dating, technical and technological analysis of ceramics and study of paleosols buried under kurgans. The paleopedological analysis was a key approach because the relative chronological order of the construction of kurgans was initially determined within one kurgan cemetery based on morphological observation and physical and chemical properties of the buried paleosols.Five kurgan cemeteries (which included 19 kurgans overall) of the Timber-grave culture were studied in the Orenburg region (the Southern Cis-Ural). It was found that the paleosols buried under the earliest kurgans of the studied culture show the maximal values of soil bulk density in the humus and carbonate horizons, the minimal content of humus in the uppermost 50 cm of the profile, the highest content of carbonates and the closest to surface location of the Bk horizon, the highest content of gypsum, and the highest portion of exchangeable sodium of the sum of exchangeable bases. Based on the set of mentioned properties of the buried paleosols, the transitional and the latest groups of kurgans were also suggested. In the latest group, the paleosols show minimal values of bulk density, maximal content of humus in the uppermost 50 cm, minimal content of carbonates and total lack of gypsum and exchangeable sodium throughout profiles. Such differences in the paleosols' properties buried under different groups of the Timber-grave kurgans were probably caused by climatic fluctuations during the period of the culture's functioning. The reconstruction showed that, in the most part, this culture had been developed in favorable climatic conditions with a sufficient quantity of precipitation and comparatively soft climatic continentality, whereas the previous period was characterized by an arid and continental climate.Based on archaeological observation, radiocarbon dating, technical and technological analysis of ceramics, three chronological stages were allocated in the history of the functioning of the Timber-grave antiquities for the steppe Cis-Ural. According to calibrated radiocarbon dates, the chronological limits are as follows: the first stage – XIX century BC, the second – XVIII – XVII centuries BC, and the third – XVII – XV centuries BC.