Iron mineralogy and speciation of sediment iron-bearing minerals in mangrove forest: Case study of Zhangjiang estuary, China
Iron mineralogy and speciation of sediment iron-bearing minerals in mangrove forest: Case study of Zhangjiang estuary, China
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红树林沉积物含铁矿物的铁矿物学和形态：以中国张江口为例
DOI：
10.1016/j.marpolbul.2019.110800
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发表时间：
2020
影响因子：
5.8
通讯作者：
Lu Haoliang
中科院分区：
文献类型：
--
作者：
Yang Dan;Liu Jingchun;Zhao Weiwei;Huang Qi;Xue Liyang;Yan Chongling;Lu Haoliang
对潮间带条件下铁形态的研究很少，很少关注了解 Fe3+–Fe2+ 的地球化学行为及其生物地球化学过程。这里，在中国张江口云霄红树林中收集了一个沉积岩芯，并通过磁力法和穆斯堡尔光谱法测定了铁矿物学。磁化率、非磁滞剩磁磁化率和饱和等温剩磁的变化与具有较小反铁磁分数的赝单畴软矫顽成分的变化有关，并且通过不依赖频率的交流磁化证实了超顺磁性颗粒的最小浓度的存在。 L比与硬等温剩磁之间的正相关关系与高矫顽力反铁磁矿物的分布一致。在 295 K 时，样本的穆斯堡尔谱与单个磁性六重态（赤铁矿）和两个磁性双峰（顺磁性 Fe2+ 和顺磁性 Fe3+）非常吻合。磁数据和穆斯堡尔光谱的有用性可以为跟踪潮间带条件下铁形态和相的变化提供有价值的分析工具。
Few investigations of iron speciation exist in intertidal conditions with little attention given to understanding the geochemical behavior of Fe3+–Fe2+and its biogeochemical processes. Here, one sediment core was collected in Yunxiao mangrove forests, Zhangjiang estuary, China and iron mineralogy was determined by magnetic methods and Mössbauer spectroscopy. Changes in magnetic susceptibility, susceptibility of anhysteretic remanent magnetization, and saturation isothermal remanent magnetization were linked to changes of pseudo-single domain soft coercive components with minor antiferromagnetic fractions and the presence of minimal concentrations of superparamagnetic particles was confirmed by the no frequency dependent of AC magnetization. A positive correlation between L-ratio and hard isothermal remanent magnetization is congruent with the distribution of high-coercivity antiferromagnetic minerals. At 295 K, the Mössbauer spectrum of specimens was well fitted with a single magnetic sextet, hematite and two magnetic doublets, paramagnetic Fe2+and paramagnetic Fe3+. The usefulness of magnetic data and Mössbauer spectroscopy could offer valuable analytical tools for tracking changes of iron speciation and phase in the intertidal conditions.