Mineralogical composition of tidal flat sediments in Japan
Mineralogical composition of tidal flat sediments in Japan
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DOI：
10.1080/00380768.2020.1787082
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发表时间：
2020-07
影响因子：
2
通讯作者：
Shota Asakawa;Tetsuhiro Watanabe;H. Lyu;Shinya Funakawa;H. Toyohara
中科院分区：
文献类型：
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作者：
Shota Asakawa;Tetsuhiro Watanabe;H. Lyu;Shinya Funakawa;H. Toyohara
摘要日本对潮滩的矿物学研究十分有限，尽管潮滩的矿物组成会影响其水质净化和有机质保存功能。本研究调查了日本主要潮滩的矿物学，并阐明了影响矿物学的因素。在日本各地21个潮滩的46个地点收集了沉积物样本。分别使用配备有能量色散光谱仪和X射线衍射仪的扫描电子显微镜鉴定细砂部分中的原生矿物和粘土部分中的次生矿物。用草酸铵萃取法测定了反映火山物质影响的活性铝和铁含量。北海道和千叶沉积物中细砂组分中火山玻璃含量较高（平均值± SD：40 ± 15%）。北海道和千叶沉积物中活性铝和铁含量与粘粒含量的比值较高。来自海湾内部区域的沉积物（例如，来自爱知和佐贺的那些）在粘土部分中具有在海洋中形成的蒙皂石和在相当平静的条件下沉积的蒙皂石。冲绳南部的沉积物中含有蒙皂石，而千叶和德岛的沉积物中含有可能来自流域土壤的蛭石。潮滩沉积物的矿物学受火山活动、沉积位置和流域土壤的影响。
ABSTRACT There are limited studies on the mineralogy of tidal flats in Japan even though the composition would affect the functions of water purification and organic matter preservation. This study investigated the mineralogy of major Japanese tidal flats and clarified factors affecting the mineralogy. Sediment samples were collected at 46 sites from 21 tidal flats throughout Japan. Primary minerals in the fine sand fraction and secondary minerals in the clay fraction were identified using a scanning electron microscope equipped with an energy dispersive spectroscope and an X-ray diffractometer, respectively. Active Al and Fe content that reflect the influence of volcanic materials were measured by acid ammonium oxalate extraction. The sediments from Hokkaido and Chiba had higher content of volcanic glasses (mean ± SD: 40 ± 15%) in the fine sand fraction. The sediments from Hokkaido and Chiba had higher ratios of active Al and Fe content to clay content. The sediments from inner regions of the bays (e.g., those from Aichi and Saga) had smectite that forms in the sea and sediment under a rather calm condition in the clay fraction. The sediments from southern Okinawa contained smectite and those from Chiba and Tokushima contained vermiculite that would have come from the soils in the watersheds. Mineralogy of the sediments in the tidal flats was affected by 1) volcanic activity, 2) location of sedimentation, and 3) soils in the watersheds.