长江河口涨落潮槽沉积物特征及其动力响应  

Sedimentary Features of Sediment and Their Responses to Dynamics in the Flood and Ebb Channel of the Changjiang Estuary

作　　者：王永红[1] 沈焕庭[2] 李九发[2] 茅志昌[2] 

机构地区：[1]中国海洋大学海底科学与探测技术教育部重点实验室,山东青岛266100 [2]华东师范大学河口海岸国家重点实验室,上海200062

出　　处：《沉积学报》2009年第3期511-517,共7页Acta Sedimentologica Sinica

基　　金：国家自然科学基金重点项目(批准号:40334038);国家自然科学基金(批准号:40572077);"973"项目(编号:2005CB4022304)的联合资助

摘　　要：涨落潮槽是河口区的重要地貌单元,涨落潮槽的水动力有着明显的差异。通过对涨潮槽新桥水道和南小泓以及落潮槽南支主槽和南港表层沉积物的粒度、粘土矿物、重矿物以及磁性特征分析,发现落潮槽表层沉积物的粒径较粗,为粉砂质砂,涨潮槽沉积物主要是砂质粉砂。在双向水流的作用下,粘土矿物重新发生分配,涨落潮槽粘土矿物的组分变化不大。涨潮槽的重矿物颗粒百分含量中,稳定的不透明矿物比落潮槽有所减少,而比重小的片状矿物有所增加,碳酸盐含量较高。磁性矿物的含量在不同的地方相差很大,落潮槽中的亚铁磁性矿物含量高于涨潮槽。这些沉积特性的不同是对涨落潮槽内水动力差异响应的结果。Flood and ebb channel are the important geomorphologic units and different hydrodynamic properties exist in these channels. Based on the analysis of particle size, clay and heavy mineral and magnetic features of the sediments in the flood and ebb channels of the Changjiang Estuary, it is found that there are different sedimentary features in the flood and ebb channels. Particle sizes of the sediments in the flood channel are coarser than that in the ebb channel. Distribution and concentrations of clay minerals in the flood channel sediment are similar with those in the ebb channel due to the dual-direction currents. Concentration of heavy minerals in the ebb channel is higher than that in the flood channel because there is strong ebb tide current and similarly there are more ferrimagnetic mineral in the ebb channel.

关 键 词：长江口 涨落潮槽 沉积特征 动力响应 

分 类 号：P512.2[天文地球—地质学] P343.5