Key Laboratory of Coastal and Wetland Ecosystem, Xiamen University, Xiamen 361102, China.
Key Laboratory of Coastal and Wetland Ecosystem, Xiamen University, Xiamen 361102, China; State Key Laboratory of Marine Environmental Science, Xiamen University, Xiamen 361102, China.
Mar Pollut Bull. 2020 Feb;151:110800. doi: 10.1016/j.marpolbul.2019.110800. Epub 2020 Jan 29.
Few investigations of iron speciation exist in intertidal conditions with little attention given to understanding the geochemical behavior of Fe-Fe 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 Fe and paramagnetic Fe. 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.
很少有研究关注铁的形态在潮间带条件下的地球化学行为及其生物地球化学过程。本研究在中国漳江河口云霄红树林区采集了一个沉积物岩芯，通过磁学方法和穆斯堡尔谱研究了铁的矿物学特征。磁化率、非磁滞剩磁磁化率和饱和等温剩磁磁化率的变化与假单畴软矫顽力分量的变化有关，外加具有最小浓度超顺磁颗粒的存在，通过交流磁化率的无频率依赖性得到证实。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，样品的穆斯堡尔谱很好地拟合了单个磁性 sextet、赤铁矿和两个磁性双峰，顺磁 Fe 和顺磁 Fe。磁学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的形态和相的变化提供有价值的分析工具。
