Iron isotopes in the Amazon River system: Weathering and transport signatures
Iron isotopes in the Amazon River system: Weathering and transport signatures
复制标题
DOI：
10.1016/j.epsl.2006.05.004
复制
发表时间：
2006-08-15
影响因子：
5.3
通讯作者：
Boyle, E. A.
中科院分区：
文献类型：
--
作者：
Bergquist, B. A.;Boyle, E. A.
对亚马逊河水系的痕量金属清洁浮游生物拖网、河流样本、气溶胶渗滤液和孔隙水样本进行了铁同位素组成的测量。观测到的总体同位素范围为千分之1.5，不同类型的支流之间存在铁同位素的变异性。两个主要航道点位的溶解态Fe和悬浮态Fe的同位素组成相似(约为-0.1~-0.3‰)。相反，富含有机物质的支流内格罗河的溶解铁和悬浮物Fe在同位素上是不同的，溶解的铁的同位素稍重(+0.3‰)，悬移质的Fe的同位素较轻(-0.9‰)。来自亚马逊地区的同位素最轻的样本是陆架孔隙水(-1.3‰)。在河水-海水混合实验中，利用同位素重铁的絮凝作用，对河水中溶解铁的铁同位素信号进行了修正。自然样品包括生物样品和水样的铁同位素组成的变异性表明，环境中的铁生物地球化学与显著的分馏有关。(C)2006爱思唯尔B.V.保留所有权利。
Trace metal clean plankton tows, river samples, aerosol leachates, and porewater samples from the Amazon River system were measured for their iron isotopic composition. The overall isotopic range observed was 1.5 parts per thousand with Fe isotopic variability observed between different types of tributaries. Dissolved Fe and suspended load Fe from two main channel sites were isotopically similar (approximate to -0.1 to -0.3 parts per thousand). In contrast, the dissolved Fe and suspended load Fe from an organic rich tributary, the Negro River, were isotopically distinct with the dissolved slightly isotopically heavy (+0.3 parts per thousand) and the suspended load isotopically light (-0.9 parts per thousand). The isotopically lightest sample from the Amazon region was shelf porewater (-1.3 parts per thousand). In river water-seawater mixing experiments, the Fe isotopic signal of dissolved Fe of river water was modified by flocculation of isotopically heavy Fe. The variability of the Fe isotopic composition of natural samples including biological and aqueous samples demonstrates that significant fractionation is associated with Fe biogeochemistry in the environment. (c) 2006 Elsevier B.V. All rights reserved.