Lithology of recent sandy sediments of Lake Baikal

Evidence from the Olkhon Island-Maloe More Strait area, one of the most representative areas of Lake Baikal, has revealed the following unique phenomenon. Under certain favorable conditions, the transport of sedimentary matter to water basin from land is supplemented with the abundant delivery of loose material in the form of sand flows over large areas (up to 3 km² ) to the adjacent coast. We have revealed a specific cycle of material (reversible lithoflow) accompanied by the differentiation of sediments. The pelitic and silty fractions are separated from the psephitic and psammitic fractions in the subaqueous setting. The eolian transport of the psammitic material from the beach zone into the island is predominated by the removal of the medium-grained sand (fraction 0.5–0.25 mm). The mineral composition of main sources of terrigenous material is given. Formation conditions of the areas of eolian sands and their mineral and grain-size compositions, which reflect the existence of reversible lithoflows on the Baikal coast, are described. The physicomechanical properties (strength and adherence) of sandy sediments are assessed.Translated from Litologiya i Poleznye Iskopaemye, No. 2, 2005, pp. 133–142.Original Russian Text Copyright © 2005 by Akulov, Agafonov, Lomonosova, Vologina.