Lithology and biostratigraphy of the Holocene succession of Lake Kuzi, Vidzeme Heights (Central Latvia)

Abstract

Holocene sediment profile from a paludified near-shore area of Lake Kńzi (Vidzeme Heights, Central Latvia) was investigated using lithological and palaeobotanical (pollen and macrofossil analysis) methods and accelerator mass spectrometry AMS 14 C dating. The results of this first comprehensive study of a Holocene sediment core from the Vidzeme Heights indicate that at the beginning of the Early and at the end of the Late Holocene the lake level was low and fen peat accumulated around the lake. From ca. 9000 BP up to 1500 BP the mire was flooded and gyttja with interlayers of sand and peat accumulated. The water level fluctuations are clearly represented in the lithological succession and pollen spectra. We compared the L. Kńzi pollen diagram with well-studied sites from the Haanja Heights, which have a similar genesis. The most obvious difference in these diagrams is the earlier appearance (9200 BP) of Picea pollen in the L. Kńzi profile and its dominance up to 1000 BP. Comparative analysis of the lithology and pollen spectra from L. Kńzi and reference profiles from the Haanja Heights indicate the importance of broad regional factors in influencing the pollen spectra.