Abstract The varved sediment of Lake Gościąz (Central Poland) is one of the most detailed and complete climate archives of the Late Glacial and the Holocene in Central Europe. Here, we present microfacies analyses in combination with μXRF core scanning and a detailed varve chronology of a new and continuous GOS18 sediment record. This record presents six lithozones that mark the most prominent depositional and geochemical changes during the Holocene and Late Glacial. Varve boundaries and five main varve microfacies types were distinguished under petrographic microscope. Analysis provides detailed insights into depositional processes and its changes since the Late Glacial. Microfacies components were used to interpret processes leading to varve formation. A new and independent chronology is obtained by triple varve counting on petrographic thin sections that is complemented by 137Cs measurements and 14C AMS dating of terrestrial plant remains. The age-depth model consists of three parts: (1) the upper part (0–520 cm) that is primarily based on varve counting, (2) the middle part (520–758 cm) obtained through age-depth modelling and (3) the lower part (758–1897 cm) developed by varve counting. The bottom of the composite profile coincides with the onset of lacustrine sedimentation in the late Allerod at 12,834 +134/-233 varve yr BP. The largest shift in geochemistry, expressed by log(Ca/Ti) and log(Si/Ti) ratios show a rapid increase of calcite precipitation and primary productivity at 7940 +112/-168 varve yr BP. Possible triggers for this include local changes in hydrology as the formation of “Na Jazach” system due to the Ruda River development and fluctuations of lake water level.

中文翻译：

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来自 Gościąż 湖（波兰）新沉积物记录的 Varve 微相和年代学

摘要 Gościąz湖（波兰中部）的沉积物是中欧晚期冰川和全新世最详细和最完整的气候档案之一。在这里，我们结合 μXRF 岩心扫描和新的连续 GOS18 沉积物记录的详细变量年表进行了微相分析。该记录提供了六个岩石带，它们标志着全新世和晚冰期期间最显着的沉积和地球化学变化。在岩相显微镜下区分了变质边界和五种主要的变质微相类型。分析提供了对晚冰期以来沉积过程及其变化的详细见解。微相成分被用来解释导致斑纹形成的过程。通过对岩相薄切片进行三重变流计数，并辅以 137Cs 测量和陆地植物遗骸的 14C AMS 测年，获得了一个新的独立年表。年龄深度模型由三部分组成：（1）主要基于斑纹计数的上部（0-520 cm），（2）通过年龄深度建模获得的中部（520-758 cm）和（ 3）下部（758-1897 cm）由斑纹计数开发。复合剖面的底部与晚 Allerod 在 12,834 +134/-233 varve yr BP 的湖泊沉积开始相吻合。地球化学的最大变化，用 log(Ca/Ti) 和 log(Si/Ti) 比表示，表明方解石沉淀和初级生产力在 7940 +112/-168 varve yr BP 快速增加。