Iron Isotope Compositions of Natural River and Lake Samples in the Karst Area, Guizhou Province, Southwest China
Iron Isotope Compositions of Natural River and Lake Samples in the Karst Area, Guizhou Province, Southwest China
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贵州省喀斯特地区天然河流和湖泊样品的铁同位素组成
DOI：
10.1111/j.1755-6724.2011.00464.x
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发表时间：
2011-06
期刊：
影响因子：
--
通讯作者：
Liang Lili
中科院分区：
文献类型：
--
作者：
Song Liuting;Liu Congqiang;Wang Zhongliang;Zhu Xiangkun;Teng Yanguo;Wang Jinsheng;Tang Suohan;Li Jin;Liang Lili
为了更好地了解喀斯特地区天然样品的铁同位素特征，对西南喀斯特地区阿哈湖（矿化水系）和红峰湖（中营养型水系）流域的河流悬浮颗粒、湖泊悬浮颗粒、湖泊沉积物、孔隙水、浮游植物和气溶胶的铁同位素组成进行了研究。样品δ56Fe的变化范围为-2.03‰~ 0.36‰。气溶胶和浮游植物的铁同位素组成与火成岩的平均值相似或稍重。河流悬浮颗粒物（SPM）铁同位素组成主要受支流类型的影响。受煤矿污水严重污染的支流中，除AR2同时受煤矿污水和污水污染外，夏季各支流中悬浮颗粒物δ56Fe值均为负（-0.89‰~ -0.31‰），冬季δ56Fe值均显著升高。湖泊特征对悬浮物、湖泊沉积物和孔隙水的铁同位素组成有重要影响。洪峰湖表层沉积物铁的δ56Fe值为-0.04‰~ 0.13‰，而阿哈湖表层沉积物铁的δ56Fe值为-0.42‰~ -0.09‰。洪峰湖后武（HW）站沉积物δ56Fe平均值为0.09‰，孔隙水δ56Fe同位素组成较轻，在-0.57‰~ -0.31‰之间；没有观察到明显的变化。阿哈湖两江口（LJK）站的活性铁含量和硫酸盐浓度均较高。在沉积物表面附近取样的孔隙水中，由于Fe的反应性再循环，包括同化铁还原、吸附和铁硫化物的形成，其δ56Fe值低至-2.03‰，最高可达0.12‰，埋藏深度为10 cm。而LJK沉积物则呈现相反的变化趋势。1 cm深度沉积物的δ56Fe值为-0.59‰，随埋深的增加δ56Fe值降低至-1.75‰。研究表明，地表环境中存在显著的铁同位素分馏。颗粒铁的同位素组成受到铁源的严重影响，铁生物地球化学循环对湖泊沉积物中铁同位素分异有重要影响，特别是当存在大量的活性铁和硫酸盐时。
To better understand the Fe isotope characteristics of natural samples in the Karst area, the Fe isotope compositions of riverine suspended particulates, lake suspended particulates, lake sediments, porewaters, phytoplanktons, and aerosols in the watersheds of Lake Aha (a mineralized water system) and Lake Hongfeng (a mesotrophic water system), which are located in the Karst area, southwest China, were investigated. The studied samples displayed a variable range between δ56Fe=–2.03‰ and 0.36‰. Aerosols and phytoplanktons have similar or slightly heavier Fe isotope compositions relative to the average of igneous rocks. Fe isotope compositions of riverine Suspended Particulate Matter (SPM) were mainly affected by the types of tributaries. Suspended particulates collected from tributaries seriously contaminated with coal mine drainages displayed negative δ56Fe values (–0.89‰ to –0.31‰) during summer, and there were significant increases of δ56Fe values in winter, except AR2, which was polluted with both coal mine drainage and sewage effluent. Characteristics of lakes have important influences on Fe isotope compositions of suspended particulates, lake sediments, and porewaters. The epilimnetic particulate Fe of Lake Hongfeng had δ56Fe=–0.04‰ to 0.13‰, while lighter Fe isotope compositions were measured for particulate Fe from Lake Aha, ranging from –0.42‰ to –0.09‰. Sediments collected from Hou Wu (HW) station of Lake Hongfeng have an average δ56Fe value of 0.09‰ and their corresponding porewaters have lighter Fe isotope compositions, ranging from –0.57‰ to –0.31‰; no significant variations have been observed. For the Liang Jiang Kou (LJK) station of Lake Aha, the content of reactive Fe and the concentration of sulfate were all high. Due to the reactive Fe recycling, including dissimilatory Fe reduction, adsorption, and Fe–sulfide formation, porewaters sampled near the sediment surface have been found to have a δ56Fe value as low as –2.03‰ and an increase up to 0.12‰, with a burial depth of 10 cm. In contrast, an opposite variation trend was found for LJK sediments. Sediments sampled at 1‐cm depth had a value of δ56Fe=–0.59‰ and decrease as low as –1.75‰ with burial depth. This investigation demonstrated that significant Fe isotope fractionations occur in surface environments. Fe isotope compositions of particulate Fe were seriously affected by Fe sources, and Fe biogeochemical recycling has an important influence on Fe isotope fractionations in lake sediments, especially when there are significant amounts of reactive Fe and sulfate.
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DOI：
10.1111/j.1755-6724.2006.tb00278.x
发表时间：
2006-08
期刊：
Acta Geologica Sinica ‐ English Edition
影响因子：
--
作者：
G. Dević;P. Pfendt;B. Jovančićević;Z. Popović
通讯作者：
G. Dević;P. Pfendt;B. Jovančićević;Z. Popović
影响因子：
5
作者：
Balci, N;Bullen, TD;Mandernack, KW
通讯作者：
Mandernack, KW
影响因子：
5.8
作者：
A. Draut;P. Clift
通讯作者：
A. Draut;P. Clift
影响因子：
5
作者：
S. Welch;B. Beard;C. Johnson;P. S. Braterman
通讯作者：
S. Welch;B. Beard;C. Johnson;P. S. Braterman
影响因子：
4.5
作者：
Evans, JC;Prepas, EE
通讯作者：
Prepas, EE