Holocene environments on the west‐central Kola Peninsula (north‐west Russia): lithology, chronology and biostratigraphy records from Lake Tikozero and a neighbouring bog

Abstract

ABSTRACTThe paper studies sediments from Lake Tikozero that have accumulated successively in the littoral of Lake pre‐Imandra, Imandra lagoon, and an open lake isolated from a parental freshwater body. The ‘Apatity’ bog was concurrently formed on the Lake Imandra coast. Lithological, 14C, pollen and diatom data and findings of previous investigations provide the regional Holocene stratigraphy, which is subdivided into the early (c. 11 550–8200 cal a bp), middle (c. 8200–4000 cal a bp) and late (last 4000 cal a bp) Holocene sub‐stages. In the early Holocene, environments became favourable for diatoms after c. 9700 cal a bp. Birch phytocoenoses and pine forests with birch flourished in the area. In the middle Holocene, the west‐central Kola Peninsula was covered by a pine‐birch forest with alders. Lake Tikozero became shallow and desiccated in a warm and dry climate between c. 6300 and 4000 cal a bp; and a Sphagnum raised bog developed in the adjacent area, provoked by lowering of the water table. Spruce appeared in a pine‐birch forest and indicates a colder and wetter climate in the late Holocene. The flooding of Lake Imandra created a number of new small lakes; and fens occurred along the wet shores.