Olga Korsakova, Dmitry Tolstobrov, Svetlana Nikolaeva, Vasily Kolka , AlyonaTolstobrova
Lake Imandra depression in the Late Glacial and early
Holocene (Kola Peninsula, north-western Russia)
The paper summarizes the evidence of litho-, biostratigraphy
and 14C dating of sedimentary sequences studied in natural outcrops and bottom
deposits in small lakes, as well as data on coastal morphology in the
depressions of Ekostrovskaya and Babinskaya Imandra, the southern sub-basins of
Lake Imandra. Lithological, 14C and diatom data suggest that the brackish-water
reservoir followed by the fresh-water one existed in the Ekostrovskaya Imandra
depression during the Younger Dryas chronozone prior to 11,400cal. yr BP. The
Fennoscandian Ice Sheet margin is assumed to have been located in the Lake
Imandra basin, covering western Babinskaya Imandra earlier than c. 10,250
cal. yr BP. The early Holocene c. 11,400–8,500 cal. yr BP was marked by a
significant westward retreat of the ice margin in the western Lake Imandra
depression and adjacent areas, and an extensive fresh-water pra-Imandra Lake
basin was formed there. At the end of the Preboreal, earlier than c. 9,210–8,500
cal. yr BP, the pra-Imandra Lake coastline was at least 16–18 m higher than the
modern one, as can be assumed according to coastal morphology and
lithostratigraphical data. The coastline of that reservoir changed, water
square slightly reduced, and isolated small lakes emerged on coasts during the
early Holocene.