中文摘要：

文章对烂沙洋海区的3个钻孔进行的沉积学、古生物学和年代学的分析,就烂沙洋的稳定性进行了研究.在千年尺度上,研究区一直处在相对稳定的环境,钻孔所揭示的沉积速率为2.16～4.67mm/a,水深变化幅度不大;在C孔所在的深槽区,有12m的以包卷层理、扰动层理为特征的淤积层,颗石的特点显示其来源于水深较浅处,通过1992年、1994年和2003年共3个时段的海图对比,该淤积层形成于近年,结合其沉积结构分析,该淤积层应为与事件相伴的事件沉积,工作区的整体冲淤基本平衡.

英文摘要：

The purpose of the research is to analyze the stability of the Lanshayang Channel. As a tidal channel, the Lanshayang Channel is located in the south part of the radial sand ridge field of the Yellow Sea. It was proposed to be the candidate location for a harbor. Previous research has shown that the radial sand ridge field has been stable for thousands years. However, few researches have been carried out directly on the stability of the Lanshayang Channel itself, which is, by all means of, the fundamental pre-condition for the harbor construction. To understand the local evolution history during the past thousand years we studied the sedimentology, paleontology, and chronology of three cores （A, B, C） collected across the Lanshayang Channel. Results from Core A and B show that during the past thousand years, the area of these cores has been stable, with very little siltation rate （Core A 4.00 ～ 4.67mm/a and Core B 2.16mm/a）. Coccolith abundance also shows that the ancient water depthes are around 10m or less at both sites of core A and B, which coincides with the current water depth. Results of Core C are however more complicated. Core C is located at the bottom of this channel, with current water depth around 18m. As this place was designed to be the harbor pool site, the stability of this area is extremely important for the construction of the harbor. The upper part of Core C, about 12m in thickness is unexpectedly characterized by some convolute bedding and disturbed bedding, which might possibly be caused by earthquakes or storm surges. The coccolith abundance shows that the ancient water depth of this upper part is around 10m, but of the lower part over 20m. In order to resolve this problem, charts of this area drawn in different years （1992, 1994 and 2003 ） were analyzed by GIS. The analysis reveals that in the past decade, water depth of this area has been changed from 30m to 18m, which supports the following assumptions： The upper part of Core C was formed in the past decade. Its wate