Analysis of bottom sediments of small lakes in Central Karelia

Abstract

Data on the particle size distribution of bottom sediments in small lakes of Central Karelia are presented. Sediment fraction sizes in the study area Lake Torosjarvi varied from very fine sand to silty clay. The prevalent fraction was coarse silt. The paleo-hydrodynamic environment for sedimentation of the rocks was analyzed using the genetic diagram by R. Passega. Three intervals were characterized as turbidite deposits, the rest of the intervals fell in the zone of deposits left by low-velocity streams. The study of changes in sedimentation in Lake Torosjarvi suggests there occurred five shifts in the dynamic water regimes in the course of the lake formation.