Diatom response to environmental changes of the northern Okhotsk area (Magadan region) during late pleistocene-holocene from Gryazevoe Lake

Abstract

The study of diatoms from the sediments of well Gz-1 (Gryazevoe Lake, Magadan Region) allowed us to identify the response of diatom communities to environmental changes in the Late Pleistocene and Holocene and establish the main stages of the transformation of the lake ecosystem. Three diatom zones and four subzones were identified based on changes in the concentration of diatom floras in sediments, the ratio of representatives of ecological groups and dominants, reflecting the evolution trend of the lake diatom flora during the transition period from the last glacial maximum to the Holocene. This trend is similar to the changes in the lake diatom communities of the Arctic regions noted for the last millennium in terms of the change of taxonomic composition and dominants. The data of diatom studies, lithological and petrophysical characteristics of sediments indicate that the most significant changes in the natural environment occurred at the Pleistocene-Holocene boundary from 12.6 to 11.1 thousand years ago.

Keywords

• diatom
• climate changes
• paleolimnology
• pleistocene
• holocene
• magadan region