data for HZK02 (grain size and geochemistry)
Description
Granularity is a useful indicator of the hydrodynamic conditions in the depositional environment, and Median sizes (Mz) are employed to evaluate the overall grain size (Liu et al., 2016; Li et al., 2020). Grain size analyses were conducted on subsamples using a laser particle size analyzer (Anton Paar PSA1190, Austria), with discrepancies between measurements being less than 1% (Jiang et al., 2023b). To remove carbonates and organic matter, samples were pretreated with 30% H2O2 and 10% HCl, followed by an incubation period of at least 24 h. Subsequently, a 5.1% sodium hexametaphosphate solution was employed to enhance sediment dispersion. All grain size measurements were performed in duplicate, with deviations not exceeding 1%. The concentrations of major and trace elements in sediment were examined at the Experimental Testing Center of Qingdao Institute of Marine Geology. The sample was first dried at a constant temperature (<60 °C), then ground to below 250 mesh using an agate mortar for elemental analysis. The primary components, namely SiO2, Al2O3, Fe2O3, CaO, MgO, Na2O, K2O, TiO2, and MnO, were identified through X-ray fluorescence (XRF) spectrometry. Inductively coupled plasma-mass spectrometry (ICP-MS, Thermo Scientific XSERIES 2) was employed for trace element analysis, with pretreatment methods derived from previous studies (Gu et al., 2017; Peng et al., 2021). The relative error of the elements was found to be less than 5% based on repeated measurements of multiple samples and standard sample measurements (Yuan et al., 2023).