邢超锋, 何青, 邓智瑞, 王宪业, 郭磊城. 长江口航道柱样沉积物特征及泥沙来源[J]. 海洋地质与第四纪地质, 2015, 35(5): 9-17. DOI: 10.16562/j.cnki.0256-1492.2015.05.002
引用本文: 邢超锋, 何青, 邓智瑞, 王宪业, 郭磊城. 长江口航道柱样沉积物特征及泥沙来源[J]. 海洋地质与第四纪地质, 2015, 35(5): 9-17. DOI: 10.16562/j.cnki.0256-1492.2015.05.002
XING Chaofeng, HE Qing, DENG Zhirui, WANG Xianye, GUO Leicheng. STUDY OF SEDIMENT GRAIN SIZES AND SOURCES FOR THE SHORT CORES COLLECTED FROM THE NORTH PASSAGE OF YANGTZE ESTUARY[J]. Marine Geology & Quaternary Geology, 2015, 35(5): 9-17. DOI: 10.16562/j.cnki.0256-1492.2015.05.002
Citation: XING Chaofeng, HE Qing, DENG Zhirui, WANG Xianye, GUO Leicheng. STUDY OF SEDIMENT GRAIN SIZES AND SOURCES FOR THE SHORT CORES COLLECTED FROM THE NORTH PASSAGE OF YANGTZE ESTUARY[J]. Marine Geology & Quaternary Geology, 2015, 35(5): 9-17. DOI: 10.16562/j.cnki.0256-1492.2015.05.002

长江口航道柱样沉积物特征及泥沙来源

STUDY OF SEDIMENT GRAIN SIZES AND SOURCES FOR THE SHORT CORES COLLECTED FROM THE NORTH PASSAGE OF YANGTZE ESTUARY

  • 摘要: 根据2014年1月北槽航道坝田区采集的13组浅钻柱状样(柱长为19~107 cm),着重分析了浅钻柱状样沉积物的粒度特性。研究结果表明:北槽上段和中段呈南粗北细的沉积物分布格局,南北侧沉积物中值粒径分别为29~40和14~18 μm;北槽下段南北两侧沉积物粗细差异趋同,中值粒径范围为23~27 μm。沿北槽纵向,南侧沉积物中值粒径和砂的含量自口内向口外呈减小趋势,而北侧正好与此相反,表明北槽内涨落潮流路分歧影响泥沙的沉积和分选。北槽柱状沉积物大多存在三组关键组分,即细组分7.8~26.3 μm、粗组分37.4~126.0 μm及更粗组分>193.5 μm,分别代表流域及海域来沙中的悬沙沉积、周围浅滩越堤供沙及风暴作用所致的泥沙沉积。其中粗组分37.4~126.0 μm为北槽坝田区沉积物的环境敏感组分。相关成果,从沉积的角度可以为深化研究长江口北槽深水航道的泥沙来源和淤积原因提供依据。

     

    Abstract: This work studies the properties of sediments from 13 short cores collected in the North Passage (NP) of the Yangtze Estuary in order to study the sediment sources. The results show that the sediment grain sizes exhibit strong spatial variations vertically and laterally. In the upper part of the NP, the median diameters (D50) of the sediments are 29~40 μm and 14~18 μm on the south and north sides, respectively. However, D50 is 23~27 μm on both sides of the lower part of the NP. Along the NP, both D50 and sand content decrease seaward on the south side, but increase seaward on the north side. The bifurcated ebbing and flooding currents in the NP is responsible for the spatial variations in sediment deposition and sorting. Moreover, there are three groups of sediments of grain sizes of 7.8~26.3 μm, 37.4~126.0 μm and>193.5 μm. They are representatives of varying sediment sources. Specifically, the fine sediment is the suspended load from the river and the sea, the coarse sediment is a kind of laterally transported sediment from the adjacent shoals to the NP, and the coarsest sediment is the lag deposits after storm surges. The coarse sediment is the most sensitive portion in the NP.

     

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