苏北陆区古潮成沙体沉积动力环境及物源

Hydrodynamic environment and source of the old tidalsand body in the coastal plain of the northern Jiangsu

苏北陆区古潮成沙体和海域辐射沙洲共同构成了统一的苏北南黄海潮成沙洲体系。在众多钻孔资料和地质雷达探测基础上，重点对苏北陆区古潮成沙体进行了沉积磁组构和重矿物分析，证明古潮成沙体属海退层序，是在南、北两侧三角洲发育过程中，以长江、黄河泥沙为主的沉积物质通过沿岸搬运进入早已存在的辐聚辐散潮流场后经潮流沉积和塑造形成的。早期沉积物质主要来自长江，晚期则主要为长江和黄河的联合供沙。认为苏北古潮成沙体是全新世中后期海陆相互作用的产物。

There is a huge tidal sand system which is composed of the old sand body distributing in the coastal plain and the radial sand ridge distributing in south Huanghai Sea. Based on numerous drilling and geo- logical ladar prospecting data , this paper emphatically studied the hydrodynamic environment and source of the old sand body by mains of magnetic fabric and heavy mineral analyses on the representative drilling cores. The results show that the old sand body was produced by tidal current in a hydrodynamic environment similar to the convergent-divergent tidal current field in south Huanghai Sea . The silt , which mainly came from the Changjiang River in the early and from the Huanghai River as well as the Changjiang River in the latter stage , was transported into the tidal current field by longshore current. So , the old sand body is a result of the middle-late Holocene continental-oceanic interaction.