冰后期钱塘江河口湾地区的海陆相互作用  

LAND-OCEAN INTERACTION IN QIANTANGJIANG ESTUARINE AREA SINCE LAST GLACIATION

作　　者：张桂甲[1] 李从先[1] 

机构地区：[1]同济大学海洋地质系,上海200092

出　　处：《海洋通报》1996年第2期43-49,共7页Marine Science Bulletin

摘　　要：钱塘江强潮型河口湾,在其冰后期发育和演化过程中受到陆地和海洋因素的综合作用.末次冰期时,海面下降,河流下切,河流携带的沉积物大多“通过”古河谷,部分粗砂砾形成滞留沉积,沉积物的物源为河流腹地,或原地侵蚀,河流因素影响较大;冰后期早期海侵过程中,海平面上升,导致河流的回水作用和溯源堆积作用;河口湾形成后,则成巨大的沉积物陷井,沉积物主要来自口外,由涨潮流带入,而河流携沙则占较小的一部分,海洋因素影响较大.这同时也产生了钱塘江河口湾沉积物分布由上游至下游呈现从粗到细的特殊沉积物分布格局.The evolution of the Qiantangjiang Estuary in the Post-Glaciation has been controlled by both land and ocean factors which dominate respectively at different stages. During Last Glaciation, strong fall in sea-level lead to rejuvenation of the ancient Qiantangjiang River and sediments loaded by the river mainly bypassed the incised valley except that some coarse sands and gravells formed the lag deposits. The sediments came from its hinderland and erosion in situ and land factors dominated at this stage. Then,the ensuing transgression resulted in rise in sea-level, backwater effect and retrogressive aggradation, with the estuary as a huge sediment 'trap'. The sediments are mainly transported from out mouth by strong flooding tidal currents, while sediments contributed by river loading con-stitue only a small portion. The ocean factors control sedimentation in the estuary at this stage. These changes in sediment suppliers and land-ocean interaction account for the specific sediment distribution in the estuary,i. e. ,coarse to fine,from upperstream to downstream respectively.

关 键 词：河口湾 海陆相互作用 钱塘江 晚更新世 

分 类 号：P634.631[天文地球—地质矿产勘探]