The record of geochemical changes in the biogenic-calcareous sediments of a kettle-hole in a young glacial landscape (western Kashubian Lakeland, North Poland)

Abstract

The paper was focused on the reconstruction of past-environmental conditions dynamics based on the geochemical characteristics of sediments filling kettle-hole located in the western part of the Kashubian Lakeland, North Poland). Stratigraphic variability of lithogeochemical constituents and a set of 13 elements (TOC, N, P, Na, Ca, Mg, K, Al, Fe, Mn, Cu, Ni, Zn) were applied for Holocene reconstruction of certain processes and conditions in the studied kettle-hole. The detailed geochemical analysis allowed us to identify 6 phases in its development: Masz-1 stage covering sedimentation of sedge-moss peat over melting dead ice at the turn of the Preboreal and Boreal periods; Masz-2 stage of the initial phase of lake development with deep-water sedimentation; Late Boreal and Atlantic stage Masz-3 related to sedimentation of lacustrine chalk; Subboreal stage Masz-4 representing the beginning of lake terrestrialization; Subatlantic stage Masz-5 of lowland bog, and Masz-6 stage covering final phase of peatland evolution due to human activity. Principle component analysis highlighted the importance of two major factors controlling the geochemical variability of the studied sediments. These are the varied origin of supplying water reflected in the sedimentation of organic-calcareous sediments (PC1), and oxidative-reduction conditions determined by water level fluctuations (PC2).