Chemical composition of ferromanganese concretions and host bottom sediments from the Black Sea@en

Ferromanganese concretions spread out on the bottom of the shallow northwest part of the Black Sea are mainly represented by Fe and Mn nodules on shells and substituted worm tubes. Element composition of these formations was measured by methods of chemical, atomic absorbtion, neutron activation, and ICP-MS analyses. It was established that Fe and Mn contents and Mn/Fe ratio in the concretions varied considerably and which controlled occurrence of several associated metals and minor elements; some of them have not been studied in Black Sea concretions before.分布于黑海西北部浅海海底的铁锰结核，主体为附着于贝壳及被置换的蠕虫管之上的铁（Fe）、锰（Mn）结核。通过化学分析法、原子吸收光谱法、中子活化分析法及电感耦合等离子体质谱法（ICP-MS）测定了该类结核的元素组成。研究发现，结核中铁、锰含量及锰铁比（Mn/Fe）存在显著差异，且该差异控制了多种伴生金属与微量元素的赋存状态；其中部分元素此前尚未在黑海铁锰结核中被研究过。