Data for: Accumulation of metals and changes in the composition of freshwater lake organic sediments during the Holocene
Distribution of metals in freshwater sediment strata formed during the Holocene in the territory of Latvia has been studied rather insufficiently. Considering the large volume of accumulated organic matter in sediments, studies of the content of metal elements in sediments can help to determine the peculiarities of metal accumulation process in limnic systems and biogeochemical cycling of metals. Lake Pilvelis, located in the eastern part of Latvia (the northern part of Europe), was selected as the study site. Lake Pilvelis is a small lake of a glacial origin, and more than 90% of its depression is filled with organic-rich sediments, such as gyttja or freshwater sapropel, with an average thickness of 450 cm. Development stages of Lake Pilvelis since circa 10 000 cal BP are described in detail by means of reconstruction of the Holocene palaeoenvironmental conditions in the lake using multiproxy sedimentary records. This study represents analysis of the elemental composition and content of metallic elements in gyttja with the main target to characterise the accumulation rate of metals in a full profile of gyttja and to determine the anthropogenic impact depending on the evolution of the lake and genesis of sediment organic matter. Correlation among the components characterising such sediments as gyttja and metallic elements showed element distribution into three main groups according to the content of organic or mineral compounds. The principal component analysis revealed four main impact factors indicating the origin of metallic elements and the accumulation tendencies of metals in sediment layers.