Varve data from a sediment profile of Lake Woserin, Germany

Abstract

Time-series of varve properties and geochemistry were established from varved sediments of Lake Woserin (north-eastern Germany) covering the recent period AD 2010-1923 and the Mid-Holocene time-window 6400-4950 varve years before present (vyr BP) using microfacies analyses, X-ray fluorescence scanning (µ-XRF), microscopic varve chronology and 14C dating. The microscopic varve chronology was compared to a macroscopic varve chronology for the same sediment interval. Calcite layer thickness during the recent period is significantly correlated to increases in local annual precipitation (r=0.46, p=0.03) and reduced air-pressure (r=-0.72, p1 standard deviation calcite layer thickness depicts a negative wave train air-pressure anomaly centred over southern Europe, with north-eastern Germany at its northern frontal zone. Three centennial-scale intervals of thicker calcite layers around the Mid-Holocene periods 6200-5900, 5750-5400 and 5300-4950 vyr BP might reflect humid conditions favouring calcite precipitation through the transport of Ca2+ ions into Lake Woserin, synchronous to wetter conditions in Europe. Calcite layer thickness oscillations of about 88 and 208 years resemble the solar Gleissberg and Suess cycles suggesting that the recorded hydroclimate changes in north-eastern Germany are modified by solar influences on synoptic-scale atmospheric circulation. However, parts of the periods of thicker calcite layers around 5750-5400 and 5200 vyr BP also coincide to enhanced human catchment activity at Lake Woserin. Therefore, calcite precipitation during these time-windows might have further been favored by anthropogenic deforestation mobilizing Ca2+ ions and/or lake eutrophication

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