Abstract
Lake sediments are used as indicators of the water body condition and changes that have recently occurred in it and in the it's catchment. The work examined two small lakes in Northwestern Russia (Arctic). Sediment cores were collected from the center of each lakes and separated into 1 cm layers. An ICP-mass spectrometer was used to determine the chemical composition. It was found both reservoirs have sediments containing organic matter (up to 61%). In both lakes, increased relative to the background of the region and the average content in the Earth's crust of rare earth elements, Th, V, Cr, etc. were detected. It was established that in the sediments of Lake Aprelskoe the total concentration of rare earth elements (1916 mg/kg) exceeds or is at one level with similar values for rare earth elements in lakes near cities and industrial enterprises. An analysis of the geological conditions of the study area (Karelia, Finland) showed that the source of anomalies of rare earth and other elements in the studied lakes may be bedrock containing increased concentrations of Y, Ce, La and other elements. However, an analysis of the geochemistry of the studied sediments also showed a technogenic influence on the lakes: an increase in the concentrations of Pb, Sd, Cd, Ni and Cu in the uppermost layers of sediments of lakes was established. Suspected sources of pollution are metallurgical plants in the neighboring region and the effect of long-range transport of metals due to the burning of coal around the world.