Chemical composition of Black Sea bottom sediments

Concentrations of major-, trace- and rare earth elements in recent and Old Black Sea bottom sediments are reported in the paper. Data presented suggest that accumulation of black shale deposits was not constrained to a certain time span but proceeds in certain modern basins and generates sediments with metal contents close to those in their ancients analogues in hydrogen sulfide contaminated environments. If REE are involved in the process, their composition can vary depending on such factors as variations in redox conditions and occurrence of phosphate and barite nodules, which can induce development of either positive or negative Eu anomalies.本文报道了近代与古黑海海底沉积物中常量元素（Major Elements）、微量元素（Trace Elements）以及稀土元素（Rare Earth Elements）的含量数据。所呈现的数据表明，黑色页岩沉积的形成并非局限于特定地质时段，而是在部分现代盆地中持续进行，并生成了金属含量与硫化氢污染环境中的古代同类沉积物相近的海底沉积物。若该过程涉及稀土元素，其组成会随氧化还原条件变化、磷酸盐与重晶石结核的产出等因素发生改变，此类因素可诱发正铕异常或负铕异常（Eu Anomaly）。