Академическое издательство «Гео»

Keywords: Baikal, pedolithological method, geoarchaeological sites, buried soils, subaerial deposits.



GEOGRAPHY AND NATURAL RESOURCES, 2016, № 3, p. 91-100

The natural-climatic events on the coast of Middle Baikal in the Early Holocene

G. Vorobyeva A.

galvorob@yandex.ru

Presented are the results from pedolithological investigations and reconstructions of the natural-climatic events in the Early Holocene (radiocarbon age 10.3–8 ka; calendar age 11.7–8.8 ka) on the coast of Middle Baikal, based on data obtained by studying the structure, composition and properties of subaerial deposits and soils in terrestrial sections. A study was made of the numerous soil profiles and sections of geoarchaeological sites. The investigation revealed common features in the layered structure of the Early-Holocene portion of the terrestrial sections and evidence of climate warming represented by buried soils, signals of a cooling in the form of cryogenic fissures, and signals of drying in the form of aeolian drifts and evidence of deflation. It is shown that the Early Holocene was the time of cardinal changes in the nature of subaerial sedimentation (calcareous deposits were replaced by noncalcareous deposits) and the pedogenesis. Considerable cold storage from inherited permafrost and humidification of soils and earth materials with moisture from the thawing of permafrost were responsible for the specific character of soil formation, and for the spread of forest vegetation under a rather low atmospheric humidity. The phases of climate warming were accompanied by an intensification of soil formation with the production of soils of two types: early boreal, and boreal. Deluvial, colluvial and (in Priol’khonie) aeolian deposits. Cryogenic fissures were generated. The issues of man’s adaptation to the cardinally changed natural conditions at the turn of the Pleistocene and Holocene and over the course of the Early Holocene are associated with the problem of Baikal’s water level and human settlement on its shores. The Lake Baikal stage at the end of the Late Neopleistocene was lower than at present; during the Early Holocene it was rising to reach at the late-boreal period the present-day level (or even exceeded it). The rises of Baikal’s stage at the Mid- and Late-Holocene period were causing scouring and destruction of the Early-Holocene sites that were located at lower elevations.

Keywords: Baikal, pedolithological method, geoarchaeological sites, buried soils, subaerial deposits.

DOI: 10.21782/GiPR0206-1619-2016-3(91-100)

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