Open AccessLateglacial and Holocene environmental history of the central Kola region, northwestern Russia revealed by a sediment succession from Lake Imandra
Author(s) -
Lenz Matthias,
Savelieva Larisa,
Frolova Larisa,
Cherezova Anna,
Moros Matthias,
Baumer Marlene M.,
Gromig Raphael,
Kostromitalia,
Nigmatullin Niyaz,
Kolka Vasili,
Wagner Benrd,
Fedorov Grigory,
Melles Martin
Publication year - 2021
Publication title -
boreas
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.95
H-Index - 74
eISSN - 1502-3885
pISSN - 0300-9483
DOI - 10.1111/bor.12465
Subject(s) - holocene , geology , younger dryas , deglaciation , physical geography , holocene climatic optimum , sediment , vegetation (pathology) , glacier , drainage basin , stadial , geomorphology , oceanography , geography , medicine , cartography , pathology
Bolshaya Imandra, the northern sub‐basin of Lake Imandra, was investigated by a hydro‐acoustic survey followed by sediment coring down to the acoustic basement. The sediment record was analysed by a combined physical, biogeochemical, sedimentological, granulometrical and micropalaeontological approach to reconstruct the regional climatic and environmental history. Chronological control was obtained by 14 C dating, 137 Cs, and Hg markers as well as pollen stratigraphy and revealed that the sediment succession offers the first continuous record spanning the Lateglacial and Holocene for this lake. Following the deglaciation prior to c . 13 200 cal. a BP , the lake's sub‐basin initially was occupied by a glacifluvial river system, before a proglacial lake with glaciolacustrine sedimentation established. Rather mild climate, a sparse vegetation cover and successive retreat of the Scandinavian Ice Sheet ( SIS ) from the lake catchment characterized the Bølling/Allerød interstadial, lasting until 12 710 cal. a BP . During the subsequent Younger Dryas chronozone, until 11 550 cal. a BP , climate cooling led to a decrease in vegetation cover and a re‐advance of the SIS . The SIS disappeared from the catchment at the Holocene transition, but small glaciers persisted in the mountains at the eastern lake shore. During the Early Holocene, until 8400 cal. a BP , sedimentation changed from glaciolacustrine to lacustrine and rising temperatures caused the spread of thermophilous vegetation. The Middle Holocene, until 3700 cal. a BP , comprises the regional Holocene Thermal Maximum (8000–4600 cal. a BP ) with relatively stable temperatures, denser vegetation cover and absence of mountain glaciers. Reoccurrence of mountain glaciers during the Late Holocene, until 30 cal. a BP , presumably results from a slight cooling and increased humidity. Since c . 30 cal. a BP Lake Imandra has been strongly influenced by human impact, originating in industrial and mining activities. Our results are in overall agreement with vegetation and climate reconstructions in the Kola region.