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硅藻贡献了海洋40%的初级生产力,在海洋生物地球化学循环中发挥重要作用,是全球碳固定的主要贡献者之一.大洋硅藻席沉积是硅藻大规模“勃发”的产物,通过对东菲律宾海136°～140°E,15°～21°N区域内藻席的分析鉴定发现,出现于这一低纬西太平洋的硅藻席的成席藻类为Ethmodiscus rex(Wallich)Hendey;同时,大量的AMS14C测年数据显示这些富含硅藻席的沉积物形成于16000～28600aBP(14C年龄)期间,即硅藻“勃发”发生于末次冰期,而其他层位并未发现藻席沉积.初步分析表明,末次冰期由于南极中层水(AAIW)北扩,将富含硅酸盐的海水带入了研究区,即南大洋的“硅溢漏”作用,使该区域硅藻得以勃发;同时,末次冰期铁输入的增加,也可能促进了该区硅藻的勃发.
Diatom contributes 40% of the primary productivity of the oceans and plays an important role in the marine biogeochemical cycle and is one of the major contributors to global carbon fixation. Through the analysis and identification of the algae in the East Philippine Sea from 136 ° to 140 ° E and from 15 ° to 21 ° N, it is found that the algal blooms present in the low-latitude Western Pacific are Ethmodiscus rex (Wallich) Hendey; meanwhile, a large number of AMS14C dating data indicate that these diatomite-rich sediments formed between 16,000 and 28,600 a BP (14C), ie diatoms and “thunderstorm” occurred in the last glacial period, while other layers did not The deposition of algae was found, and preliminary analysis showed that silicate-rich seawater was brought into the study area during the last glacial period due to the northward expansion of Antarctic intermediate water (AAIW), that is, the role of “silicon spillage” in the southern ocean Regional diatoms can flourish; at the same time, the increase of iron input in the last glacial period may also promote the blooming of diatoms in this area.