Sedimentation switch of diatoms for new understandings in ocean chemistry

硅藻结缔组织在形成大型聚集体时，往往会保留它们的化学信息。利用这一性质鉴定了硅藻的化学实体和海水中溶解稀土元素的化学种类。单个断口试样的差异太大，无法对溶解动力学进行明确的讨论。硅藻体中陆源元素含量为陆源物质的1/100-1/10。多数稀土元素在海水中以硅酸配合物的形式溶解，硅藻可以吸收它们并将其结合到藻体中。硅藻消化陆源硅酸盐，并将其融入到藻体中。硅藻体中的大部分有机物在沉降过程中容易分解，即使硅藻生产力极高，也只有不到2%的有机物残留。

Diatom frustules tend to retain their chemical information when they form mega-aggregates. Using this property the chemical entity of diatom frustulea and chemical species of dissolved rare earth elements (REEs) in seawater are identified.1.Difference in individual frustule specimens was too great to allow clear discussion on dissolution kinetics./2.Diatom frustules contain terrigenous elements at concentrations of 1/100-1/10 that of terrigenous matter./3.A majority of REEs dissolve as silicic acid complexes in seawater and diatoms can absorb them to incorporate into frustules./4.Diatoms digest terrigenous silicates to incorporate into frustules./5.Most of organic matter in diatom frustules is readily decomposed during settlement and only less than 2% of it remains even when diatomaceous productivity is extremely high.