Sedimentation switch of diatoms for new understandings in ocean chemistry

硅藻硅藻壳在形成大型聚集体时倾向于保留其化学信息。利用这一性质，对硅藻硅藻壳的化学实体和海水中溶解稀土元素的化学形态进行了鉴定。1.硅藻壳样品间的差异太大，不能清楚地讨论溶解动力学。2.硅藻硅藻壳中陆源元素的含量为陆源物质的1/100-1/10。3.大多数稀土元素以弱酸络合物的形式溶解于海水中，硅藻可以吸收它们并将其整合到硅藻壳中。4.硅藻消化陆源硅酸盐，将其并入硅藻壳。5.硅藻硅藻壳中的大部分有机质在沉降过程中很容易分解，即使在硅藻生产力极高的情况下，也只有不到2%的有机质保留下来。

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.