Grain size and chemical compositions of bottom sediments from the Amur Bay

Composition of clay minerals in the <0.001 mm size fraction from the uppermost layer of bottom sediments in the northern Amur Bay was determined by X-ray powder diffraction analysis, and enrichment of 33 elements in the <0.001 mm and <0.01 mm size fractions of surface sediments from a number of sites at the marginal filter of the Razdol'naya River were studied by ICP-MS. Fe, U, and chalcophile elements occur in the highest concentrations in sediments from all sampling sites within the filter. The bottom sediments are not enriched in trace, alkali, and alkaline earth elements. Maximum concentrations of chemical elements were found in deposits from the brackish part of the marginal filter, perhaps, because of formation of Fe and Mn (Al) hydroxides. Bottom sediments at the boundary between the brackish and marine parts of the filter contain the lowest concentrations of the examined elements.

采用X射线粉末衍射分析法，测定了阿穆尔湾北部海底沉积物最上层中<0.001毫米粒级组分的黏土矿物组成；借助电感耦合等离子体质谱法（ICP-MS），研究了拉兹多利纳亚河边缘过滤带多个站位表层沉积物中<0.001毫米与<0.01毫米粒级组分的33种元素富集特征。该过滤带所有采样站位的沉积物中，铁（Fe）、铀（U）和亲铜元素均呈现最高浓度；海底沉积物未出现微量元素、碱金属及碱土金属的富集现象。研究发现，化学元素的最高浓度出现在边缘过滤带的半咸水区域，这可能与铁（Fe）、锰（Mn）及铝（Al）氢氧化物的形成有关；而位于过滤带半咸水与海水交界区域的海底沉积物中，所检测元素的浓度最低。