Seasonal geochemical heterogeneity of sediments from a subtropical mountainous river in SE China
Seasonal geochemical heterogeneity of sediments from a subtropical mountainous river in SE China
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中国东南部亚热带山区河流沉积物的季节地球化学异质性
DOI：
10.1016/j.margeo.2020.106120
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发表时间：
2020-04
期刊：
影响因子：
2.9
通讯作者：
Zhang Wei
中科院分区：
文献类型：
--
作者：
Jian Xing;Yang Shouye;Hong Dongming;Liang Hanghai;Zhang Shuo;Fu Hanjing;Zhang Wei
浙闽山区河流具有构造稳定、流域小、中尺度、岩石相对均一、植被覆盖度高、降雨量大等特点。这些河流向海洋输送大量的沉积物和营养物质，而且在短期时间尺度上，沉积物通量的变化总是相当大。然而，这些山区河流的短期沉积物成分变化和运输机制仍然知之甚少。本文以闽江为研究对象，利用2016年10月至2017年10月一年水文周期内的悬浮颗粒物（SPM）、河床沉积物（<0. 063 mm颗粒）和闽江干流及主要支流的SPM的矿物学和微量元素地球化学数据，研究其物源和运移过程。结果表明，不同季节的悬浮颗粒物具有较强的季节性地球化学异质性，La（CN）/Yb（CN）、Th/Sc等微量元素比值与径流量呈高度正相关。成对采集的河床沉积物和SPM具有不同的地球化学组成。河床沉积物中La（CN）/Yb（CN）比值较低（约为0.0001）。10-15）和Th/Sc（ca. 2-5)的La（CN）/Yb（CN）和Th/Sc比范围，而SPM具有约1.5的La（CN）/Yb（CN）和Th/Sc比范围。14-17和CA。4-7，分别。这些结果表明，水文控制的优势岷江泥沙输移和地球化学组成的季节时间尺度。我们的结论是，暴露的河床沉积物可能是有选择地回收在旱季的泥沙运输，而汛期的SPM与河床沉积物混合较少，并可能直接从这些支流和上游主流的颗粒为主。我们认为浙闽山区河流具有响应水文气候变化的快速输沙特征，并与东亚亚热带构造活动区（如台湾）的小型山区河流具有相似的输沙行为。该案例研究还强调了多时空尺度、异质河流向海洋输入化学元素的重要性。
The Zhe-Min mountainous rivers in SE China are characterized by stable tectonics, small–mesoscale drainage basins, relatively homogenous bedrocks, dense vegetation cover and high rainfall conditions. These rivers deliver loads of sediments and nutrients to the oceans and always indicate considerably high variability of sediment flux on short-term timescales. However, short-term sediment compositional variations and transport mechanism by these mountainous rivers remain poorly understood. Here we target the Minjiang River, use mineralogical and trace element geochemical data of suspended particulate matters (SPMs) within a one-year hydrological cycle (from October 2016 to October 2017), riverbed sediments (<0.063 mm fractions) and SPMs from the mainstream and major tributaries, to investigate their provenance and transport process. The results indicate that the SPMs in different seasons have strong seasonal geochemical heterogeneity, with highly positive correlations between several trace element ratios (e.g. La(CN)/Yb(CN)and Th/Sc) and runoff of the river. Riverbed sediments and SPMs collected in pairs have distinct geochemical compositions. The riverbed sediments have relatively low La(CN)/Yb(CN)(ca. 10–15) and Th/Sc (ca. 2–5) ratios, whereas the SPMs have La(CN)/Yb(CN)and Th/Sc ratio ranges of ca. 14–17 and ca. 4–7, respectively. These findings suggest a predominant hydrologic control on the Minjiang River sediment transport and geochemical compositions on a seasonal timescale. We conclude that exposed riverbed sediments are probably selectively recycled in dry-season sediment transport, whereas the flood-season SPMs are less mixed with riverbed sediments and are likely dominated by particulates directly from those tributaries and the upper mainstream. We favor that the Zhe-Min mountainous rivers are featured by rapid sediment delivery in response to hydroclimatic changes and have similar sediment transport behaviors with those small mountainous rivers in tectonically active regions of the subtropical East Asia (e.g. Taiwan). This case study also highlights the importance of multi-spatio-temporal scale, heterogeneous river input of chemical elements to the oceans.
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影响因子：
5.3
作者：
Garzanti, Eduardo;Ando, Sergio;Lupker, Maarten
通讯作者：
Lupker, Maarten
影响因子：
3.9
作者：
H. Vital;K. Stattegger
通讯作者：
H. Vital;K. Stattegger
影响因子：
4
作者：
S. Xiong;Z. Ding;Yuanjian Zhu;Rufang Zhou;Haijian Lu
通讯作者：
S. Xiong;Z. Ding;Yuanjian Zhu;Rufang Zhou;Haijian Lu
台湾小型动态山地河流在多空间尺度上表现出巨大的沉积地球化学和物源异质性
影响因子：
5.3
作者：
Deng Kai;Yang Shouye;Bi Lei;Chang Yuan-Pin;Su Ni;Frings Patrick;Xie Xiaolei
通讯作者：
Xie Xiaolei
影响因子：
5
作者：
Canfield, DE
通讯作者：
Canfield, DE