Response of Diatoms from Gryazevoe Lake (Magadan Oblast) to Environmental Changes in the Northern Coast of the Sea of Okhotsk in the Late Pleistocene–Holocene

Abstract

The study of diatoms from the sediments of core Gz-1 (Gryazevoe Lake, Magadan oblast) has made it possible to identify the response of diatom communities to environmental changes in the Late Pleistocene and Holocene and to establish the main stages of the transformation of the lake ecosystem. Three diatom zones and four subzones, reflecting the evolution trend of the lake diatom flora during the transition period from the last glacial maximum to the Holocene, are distinguished based on the changes in the concentration of diatom valves in sediments, the ratio of representatives of ecological groups and dominants. This trend is similar to the changes in the lacustrine diatom communities of the Arctic regions noted in the last millennium in terms of the change in 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 ka.