摘要
对现代海岸带沉积的研究,它既有助于弄清海岸带的塑造过程和演变规律,也可为研究分析古海岸沉积提供依据。近年来我们对舟山普陀岛现代海岸沉积进行了调查研究,本文着重探讨该岛海岸沉积物类型和海滩不同地貌单元沉积相的标志。
Four sub-facies of modern coastel sediments of Putuo Island have been distinguished:sub-facies of the sand dune,supratidal,intertidal and subtidal belts.Each sub-facies is characterized by distinctive surface features,biotic association and sediments with differing composition,texture and structure.It is worth noting that,The water body encircling Putuo Island is strongly influenced by the southward longshore current issuing from the Yangtze River mouth.Tremendous amount of suspended matters,i.e.,silt and mud,being carried by the longshore current,become the chief source of modern subtidal sediments around Putuo Island and superficial sediments of the nearby continental shelf.Along the western and southern coasts of the island,where wave energy is low,mud flats have been developed in the main portion of intertidal belt.However,along the eastern and northern coasts of high wave energy,the supertidal,intertidal and even upper part of subtidal flats are mainly composed of gravels,coarse-to fine-grained sands which are caused by erosion of indigenous granitic rocks and basic dykes.As a whole,the grain size of tidal flat of Putuo Island decreases seaward,thus,it differs markedly from that of tidal flats of the North Sea described in the literature.
作者
严钦尚
项立嵩
张国栋
王慧中
吴邦毓
董荣鑫
Yan Qinshang;Xiang Lisong;Zhang Guodong;Wang Huizhong;Wu Bangyu;Dong Rongxin(Tong-Ji University)
出处
《地质学报》
1981年第3期205-215,共11页
Acta Geologica Sinica
