UNPRECEDENTED INCREASE IN THE CHARCOAL MACROPARTICLES IN THE BOTTOM SEDIMENTS OF THE LAKES OF THE NORTH-MINUSINSK VALLEY (SOUTH OF SIBERIA) IN THE RECENT TIME AS A POSSIBLE EVIDENCE OF ANTHROPOGENIC INFLUENCE

Abstract

In the bottom sediments of lakes Shira and Uchum, located in the south of Siberia in the steppe zone of the North Minusinsk depression (Republic of Khakassia and Krasnoyarsk Territory), distributions of charcoal particles 100 µm. The age of the studied sediments of the two lakes was up to 1400 and 500 years ago, respectively. Charcoal particles of three types were found in the sediments of both lakes. The first group has an elongated shape and is interpreted as the remains of herbaceous plants and/or needles. The second group looks like thin flat blades and is interpreted as the remains of leaves. The third group consists of bulk particles of various irregular shapes, which are presumably the remains of the combustion of wood and coal. Particles of the first type are mainly indicators of natural fires, and their flux does not show a noticeable increase in the modern period. The flow of coal particles of the second and, to the greatest extent, the third groups has increased sharply in the last about a hundred years, which reflects an increase in the amount of wood and coal burned by people in the vicinity of the studied lakes in the modern industrial period. The data obtained reflect an increase in the amount of wood and coal burned by people in the modern industrial period, as well as a possible increase in the number of wildfires, which may also be due to human activities in the form of accidental or deliberate arson. Thus, for the first time for this region, an increase in the influx of charcoal particles into the bottom sediments of lakes over the past about a hundred years has been revealed, which is unprecedented over the period covered by our study. Thus, evidence of the anthropogenic impact on the dynamics of charcoal particles in bottom sediments has been obtained. The information obtained can be useful for reconstructing the dynamics of natural fires and paleo-climate in this region of southern Siberia in the Late Holocene.