运用层序不对称性分析海平面变化特征

目前研究海平面变化的方法尚不能精确确定海平面变化，对记录海平面变化的沉积体或层序物质组成及结构特点的研究尚显薄弱。在分析层序不对称性与海平面变化的关系基础，提出层序不对称系数S0，认为海平面的升降变化对浅水沉积区影响显著，其结果必然造成层序S0的增加；海平面的升降变化对沉水沉积区影响不大，层序S0较为恒定。对进行详细研究中扬子区S0分布特点，运用S0曲线计算了中扬子区海平面变化特点，并与其他方法进行对比，认为可以用S0判断水体相对深浅，分析海平面变化。

THE CHARACTER OF SEA-LEVEL CHANGES ANALYZED BY SEQUENCE ASYMMETRY

The present research method of sea level changes has been summarized.It is considered that the present method is inaccuracy in determining the component and texture styles of the sequence formed during sea level changes. The relationship between sequence asymmetry and sea level changes has been analysed and the sequence asymmetric coefficient S 0 has been proposed. As a result,the contribution of sea level changes to sequence asymmetry in shallow water is more significant than that in deep water and the sequence asymmetric coefficient S 0 in shallow water is bigger than that in deep water. The distribution character of S 0 which reflects the character of the sea level changes was studied in the central Yangtze area.It was considered that S 0 could be used to determine the relative depth of water and to analyze the sea level change.