Was there really an Archean phosphate crisis?
Was there really an Archean phosphate crisis?
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DOI：
10.1126/science.1136328
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发表时间：
2007-03-02
期刊：
影响因子：
56.9
通讯作者：
Holland, Heinrich D.
中科院分区：
文献类型：
--
作者：
Konhauser, Kurt O.;Lalonde, Stefan V.;Holland, Heinrich D.
在太古代，大量的铁以带状铁地层的形式沉积。有人认为，氢氧化铁颗粒的沉积可能会从海洋中剥离溶解的磷酸盐，导致浮游植物生产力下降。然而，该模型没有考虑到当时海水中存在的高浓度溶解二氧化硅。我们的实验表明，二氧化硅有效地竞争与磷酸盐的水铁矿颗粒上的吸附位点。此外，二氧化硅与水铁矿的共沉淀降低了颗粒对磷酸盐的反应性。因此，太古代海洋中含有的磷酸盐可能比之前预测的要多得多。
During the Archean, massive amounts of iron were deposited in the form of banded iron formations. It has been suggested that sedimenting particles of ferric oxyhydroxide may have stripped dissolved phosphate from the oceans, causing a reduction in phytoplankton productivity. However, that model does not take into account the high concentration of dissolved silica that was present in seawater at that time. We show experimentally that silica effectively competes with phosphate for sorption sites on ferrihydrite particles. Furthermore, coprecipitation of silica with ferrihydrite reduces particle reactivity toward phosphate. Hence, Archean oceans probably contained considerably more phosphate than previously predicted.