旋回性沉积序列的形成机理分析

旋回性特征是沉积岩层最为重要的属性之一，尤其在对于区域地质背景波动做出敏感响应的陆相盆地沉积序列当中更是如此。沉积岩层的韵律性或旋回性特征由岩层的岩石学性质在纵向上的（随时间的）有规律变化所决定，这些变化主要由以下方面所体现，包括:组分变化、粒度变化、颜色变化、沉积补偿强度变化、氧化还原强度变化，以及化石群性质变化等。研究表明，沉积岩层的韵律性或旋回性特征在一定程度上受海（湖）平面变化影响，但从更加广泛的意义上来看，应是沉积过程对于区域地质背景波动的响应，其主控因素是构造波动。

Analysis on the Formational Mechanism of Depositional Cycles

Cyclicity character is one of the most important attributes of depositional strata,and it looks more important in the terrestrial sediments.Rhythmicility or periodicity of the depositional strata is materialized by the transformations of lithological characters in strata ordinally,and it is incarnated by the transformations of ingredient,granularity,color,intensity of the depositional compensation,intensity of oxidation-deoxidation,and the character of biome.Rhythmicility or periodicity of the depositional strata is influenced by the fluctuation of sea-level to a certain extent,but it must be the response of depositional course to the structural activity in extensive significance.