Lacustrine diatom oxygen isotopes as palaeo precipitation proxy of sediment core Co1321, Lake Bolshoye Shchuchye, Polar Urals, Russia@en

The dataset comprises the main geochemical characteristics of purified lake sediment samples from Lake Bolshoye Shchuchye, in the Polar Ural based on EDS and stable isotope data. Moreover, core segment (column A), composite depth (in cm; column B); calibrated age (in cal ka BP; column C) are given. Details on coring and age model are given in Lenz et al. (2021) Energy-Dispersive X-ray Spectroscopy (EDS) was carried out with a scanning electron microscope (SEM) at the German Research Centre for Geosciences (GFZ Potsdam, Germany) to assess contamination of all diatom samples (following Chapligin et al., 2012). Three replicate analyses were carried out with an excited-area size with a radius of ~200 μm at an acceleration voltage of 20.0 kV. All detectable elements were normalized to 100% weight. The results were expressed as weight percentages (in %) and displayed as oxides: SiO2 content (%); Al2O3 content (%); Na2O content (%); MgO content (%); K2O content (%); CaO content (%); MnO content (%); FeO content (%): Total sum (%) of the purified sediment sample (columns D to L). Details are given in Meyer et al. (2022) The diatom oxygen isotope composition (δ18Odiatom) from lacustrine sediments helps tracing the hydrological and climate dynamics in individual lake catchments. The oxygen isotope data has been generated in the ISOLAB Facility Potsdam including all d18Odiatom values (all in ‰ vs. VSMOW). The measured δ18O values (δ18Omeas), the standard deviation (SD) and number of replicates (N) are given (columns M to O), as well as the calculated contamination (ccont; in %) and δ18O values corrected for contamination (δ18Ocorr) (columns P to Q). The details of the contamination correction and isotope analytics are given in Meyer et al. (2022)本数据集涵盖采自极地乌拉尔（Polar Ural）大舒奇耶湖（Lake Bolshoye Shchuchye）的纯化湖泊沉积物样品的主要地球化学特征，数据基于能量色散X射线能谱（Energy-Dispersive X-ray Spectroscopy，简称EDS）与稳定同位素分析结果。此外，数据集还提供了岩芯段（列A）、复合深度（单位：厘米，列B）以及校正年龄（单位：校准千年BP，cal ka BP，列C）。岩芯获取与年龄模型的详细信息参见Lenz等（2021）的研究。为评估所有硅藻样品的污染程度（遵循Chapligin等，2012的方法），研究人员在德国地球科学研究中心（GFZ Potsdam, 德国）的扫描电子显微镜（Scanning Electron Microscope，简称SEM）上开展了能量色散X射线能谱分析。实验设置激发区域半径约200μm，加速电压为20.0 kV，每组样品开展三次重复分析。所有可检测元素均归一化至100%重量占比，结果以重量百分比（%）形式呈现，并以氧化物形式统计：二氧化硅（SiO₂）、三氧化二铝（Al₂O₃）、氧化钠（Na₂O）、氧化镁（MgO）、氧化钾（K₂O）、氧化钙（CaO）、氧化锰（MnO）、氧化亚铁（FeO）的含量（%），以及纯化沉积物样品的氧化物总合占比（%）（对应列D至列L）。详细实验方法参见Meyer等（2022）的研究。湖泊沉积物中的硅藻氧同位素组成（δ¹⁸O_diatom）可用于追溯单个湖泊流域的水文与气候动态。本次氧同位素数据在波茨坦同位素实验室（ISOLAB Facility Potsdam）完成测试，包含所有硅藻氧同位素值（均以相对于维也纳标准平均海洋水（VSMOW）的千分比‰表示）。数据集提供了实测δ¹⁸O值（δ¹⁸O_meas）、标准偏差（SD）与重复分析次数（N）（对应列M至列O），同时还包含计算得到的污染校正系数（c_cont；单位：%）以及经污染校正后的δ¹⁸O值（δ¹⁸O_corr）（对应列P至列Q）。污染校正方法与同位素分析的详细流程参见Meyer等（2022）的研究。