闽江口外潮流沙脊群特征与成因  

CHARACTERISTICS AND ORIGIN OF THE TIDAL SAND RIDGES OFF THE MINJIANG RIVER ESTUARY,SOUTHEASTERN CHINA

作　　者：卢惠泉[1,2] 吴承强[2] 许艳[2] 

机构地区：[1]中国海洋大学海洋地球科学学院,青岛266100 [2]国家海洋局第三海洋研究所,厦门361005

出　　处：《海洋地质与第四纪地质》2014年第2期27-36,共10页Marine Geology & Quaternary Geology

基　　金：国家自然科学基金项目(41276058);东沙群岛北部海域地形特征命名示范应用研究(201205004-4)

摘　　要：中国沿海很多陆架受潮流水动力的控制,发育了沙脊、沙席和沙波(沙丘)等潮流沉积地貌。闽江河口外首次发现有潮流沙脊群,沙脊群由数条大小不一呈SW—NE向的线状沙脊体组成,局部沙脊连片成为浅滩,相邻沙脊间为侵蚀沟槽,形成脊槽相间排列的地貌形态,沙脊东南翼较西北翼陡,表明沙脊有向东南方向迁移的趋势。通过对沙脊群和闽江口水下三角洲地形地貌、沉积物以及潮流场环境特征的综合分析,认为闽江口外潮流沙脊群是以古闽江口三角洲物质为基础,在全新世海侵过程中,沙脊群区处于近岸河口湾环境下发育,并在现代水动力的作用下形成与潮流方向相吻合的地貌体。Tidal currents dominate great part of China＇s continental shelves. And the tidal depositional mor- phology, such as sand ridges, sand sheets and sand waves （sand dunes） are widely distributed. However, tidal sand ridges have not been discovered off the Minjiang River Estuary before. This time we found a group of linear sand bodies in different sizes distributed off the Estuary in SW-NE direction. Some of them may join together becoming shallow banks, but there are erosional channels between most of the sand rid- ges. The southeast flank of the sand ridge is steeper than the northwest, indicating that sand ridges are migrating southeastward. According to the analysis of the topography and geomorphology, sediments and tidal current field of the area, it is concluded that the materials come from the ancient Minjiang River del- ta, that was formed in the inshore estuaries bay during the Holocene transgression. The current tidal sys- tem is the main factor to form the tidal ridge group.

关 键 词：潮流沙脊 地形地貌 潮流 闽江口外 

分 类 号：P736.2[天文地球—海洋地质]