论文部分内容阅读
长江口海区按沉积环境、沉积物成分可分为五个沉积区,即现代长江三角洲前缘沉积区、现代长江前三角洲沉积区、过渡沉积区、晚更新世古滨海沉积区和苏北浅滩沉积区。在陆架上,陆源碎屑矿物主要为石英及硅铝酸盐矿物,陆源沉积物特征元素为Si和Al。探讨沉积物Si、Al平面上(沉积区)的分布、各类沉积物及粒度组分中Si、Al的含量变化,将有助于认识长江水下三角洲沉积地球化学的特点。统计表明,古滨海沉积区SiO_2(最高
Sediment composition can be divided into five sedimentary areas according to sedimentary environment in the Changjiang Estuary. The sediments are formed in the front of the modern Yangtze River delta front, the depositional area of the modern Yangtze River delta front, the transition sedimentary area, the late Pleistocene palebuthai sedimentary area and the shallow sediment area of the north Jiangsu . On the shelf, the terrigenous detrital minerals are mainly quartz and aluminosilicate minerals, and the terrigenous sediments are characterized by Si and Al. Studying the distribution of Si and Al in the sediments and the changes of Si and Al contents in various sediments and grain-size fractions will help to understand the sedimentary geochemistry of the Yangtze River subaqueous delta. Statistics show that the ancient coastal sediment area SiO_2 (highest