2026-10-10T19:10:49Z https://www.scidb.cn/oai

10.57760/sciencedb.j00265.0002r 2026-09-17T11:22:33Z

2026-09-17 XRD, major and trace geochemical data of sedimentary rocks from borehole cores in the Middle Pleistocene - Upper Pleistocene strata of Yaohu Lake area in the Qaidam Basin doi:10.57760/sciencedb.j00265.0002r en This dataset was obtained from drill core ZK53606 in the Yahu Lake area of the Qaidam Basin, covering Middle Pleistocene to Holocene strata. In this study, powder X‑ray diffraction (XRD) semi‑quantitative mineral analysis and whole‑rock major and trace element geochemical analyses were carried out, and all experimental measurements were completed at the Salt Lake Chemical Analysis and Testing Center of the Qinghai Institute of Salt Lakes, Chinese Academy of Sciences. For XRD mineralogical analysis, 103 powdered core samples from a depth interval of 1–252 m were measured using a PANalytical X’pert Pro powder X‑ray diffractometer. The operating conditions were set at 40 kV voltage and 30 mA current with Cu Kα radiation (λ = 1.5406 Å), a scanning 2θ range of 5°–80°, and a scanning speed of 5°/min. Mineral phase identification and semi‑quantitative content calculation were performed with X’Pert High Score Plus software. The relative error of measured mineral contents is ±2%, the repeat scanning deviation of 2θ ≤ 0.01°, and the confidence level of phase identification is ≥95%. Combined with Rietveld whole‑pattern refinement, the mass fraction of each mineral phase can be accurately acquired to systematically characterize the assemblages of evaporite minerals, detrital minerals and clay minerals, and effectively reconstruct sediment provenance and the precipitation evolution of saline minerals in the lake basin. For geochemical analyses, 44 sediment samples were collected from 1–239 m depth of the same drill core. Major elements (SiO₂, Na₂O, K₂O, MgO, TiO₂, Al₂O₃, CaO, Fe₂O₃) and selected trace elements including Sc, Cr, Co and Zr were determined using a Thermo Fisher ARL Perform'x X‑ray fluorescence spectrometer (XRF). Samples were prepared by pressed powder pellets prior to measurement, and the analytical procedures strictly followed Chinese national standards GB/T 14506.28‑2010 and GB/T 14506.34‑2019. For other trace elements, a mixed‑acid digestion method was adopted: powder samples were completely digested with nitric, hydrochloric, hydrofluoric and perchloric acids, followed by heating to remove acids. After cooling, the solution was diluted to 100 mL in a volumetric flask with ultrapure water and homogenized for test. U, Th, Rb, Cs and the full suite of rare earth elements (La, Ce, Pr, Nd, etc.) were measured by a PerkinElmer NexIon 2000 inductively coupled plasma mass spectrometer (ICP‑MS), while Li concentrations were determined using an Agilent 5900 inductively coupled plasma optical emission spectrometer (ICP‑OES). This integrated dataset contains detailed mineral assemblages and comprehensive major‑trace geochemical proxies, which can systematically reveal the nature of source rocks, catchment chemical weathering intensity and elemental migration and enrichment patterns. It precisely constrains the weathering‑transport‑sedimentation evolution of the Yahu Lake catchment and paleoenvironmental changes of the salt lake, and provides robust mineralogical and geochemical data support for understanding salt formation evolution, material transport mechanisms and regional paleoclimatic changes in the Yahu Lake area of the Qaidam Basin since the Middle Pleistocene. Qaidam Basin; Yahu lake area; XRD; XRF; ICP-MS; ICP-OES Zhang Shaodong Gao Pin Cheng Kangnan Fu Deliang Cui Liao Liao Yuan Xiaolong Shen Zhiyuan Pan Tong Guo Tingfeng Jia Jiantuan Zhang Xiaodong Yin Guoshan PUBLIC https://creativecommons.org/licenses/by-nc-nd/4.0/ dataset Science Data Bank