Paleoenvironmental Reconstruction of Lake Van and Lake Erçek Over the Last Millennium Using Varved Sediments (Eastern Türkiye)

Abstract

Detailed lithological and geochemical studies of the bottom sediments were conducted based on the original sampling of brackish adjacent lakes: Lake Van and Lake Er & ccedil;ek in Eastern Anatolia, T & uuml;rkiye. Seasonal variations in the accumulation of weather-driven element content were determined using high-resolution Synchrotron Radiation X-Ray Fluorescence (SR-XRF) analysis of the annual layers in the solid prepare. The results were utilized to approximate the regional paleo-temperature of both lakes and the water level of Lake Van. Visual counting of the varve as well as annual oscillation of measured geochemical series was employed to create a time scale. The element content series were synchronized with recent changes in external climatic environments and lake water level fluctuations. Subsequently, the geochemical series were transformed into climate units, using calibration on synchronous meteorological data. Finally, the original quantitative reconstruction of the regional climate variations was performed over the last millennium period with annual time resolution; for Lake Er & ccedil;ek (840 years ago) and Lake Van (1300 years ago). It was revealed that the sediments of these adjacent lakes (Lake Van and Lake Er & ccedil;ek), located 30 km apart from each other, provided synchronous responses to regional environmental changes, which confirmed the reliability of the reconstructions.