利用砂岩中波痕的物理参数分析沉积环境
Applications of physical parameters for the ripple marks in sandstones to the analysis of sedimentary environments
-
摘要: 欧洲学者在20世纪80年代研究阿尔卑斯地区海相沉积和英国设得兰地区陆相沉积的波痕构造时建立了一系列的数学表达式。本文利用了他们的研究成果,在大王北洼陷沙河街二段砂岩中进行了应用研究。结果表明,处于特殊沉积环境下的砂岩的波痕物理参数呈有规律的变化,反映不同的水动力条件和水体深度;结合粒度分析认为,砂质颗粒在水体中主要作跳跃运动,其次是跳跃运动与悬浮运动的转换运动,部分质点作悬浮运动,反映了水体浅、能量较高。计算结果与实际观察较吻合。Abstract: With the aid of the previous results of research,the present paper focuses on the sandstones from the Da-55 well in the second member of the Shahejie Formation in the Dawangbei depression.The physical parameters display regular variations in the ripple marks from the studied sandstones in particular sedimentary environments,suggesting different water depths and energy.The grain-size analyses demonstrate that the saltation populations of the sandy grains predominate with subordinate suspension of the sandy grains in the sandstones,indicating shallower water depths and higher energy in the study area.