论老地层石英颗粒表面特征分析古沉积环境的可能性

经国内外很多学者十几年的大量工作和努力,运用扫描电子显微镜研究石英颗粒表面特征,分析搬运机理和沉积环境的工作,在现代沉积中已取得了成功,并且已成为分析现代沉积的一个重要手段和方法。然而在分析古代沉积和重建老地层砂岩的沉积环境时,由于在长期的地质时期中,石英颗粒受成岩后生作用的影响,沉积时的原始表面遭到破坏,其搬运和沉积时留在表面的特征被掩盖,使古环境的重建发生困难,研究工作进展缓慢。并且使很多学者对用扫描电子显微镜研究石英颗粒表面特征重建古环境的可能性产生了不同的意见。

THE POSSIBILITY OF RECONSTRUCTING THE ANCIENT SEDIMENTARY ENVIRONMENT BY THE SURFACE CHARACTER OF GUARTZ GRAIN IN OLD STRATA

In this paper quartz grains of sandstone are taken as examples for the discussion of the possibility of reconstructing the ancient sedimentary environment by studying the taxtures of quartz grains with scanning electron microscope.The sandstone collected at the depth of 2719m from well Ma 41 in the Liaohe Oil Field belongs to the second unit of the Shahejie Formation of Lower Tertiary. Others consider that the key to the possibility lies in the condition of quartz grain surface reformed by diagenesis. The quartz grains in ancient sediments can be used for analyzing the ancient sedimentary environment provided over 75 per cent of quartz grain surface has not been fully reformed, and half of over 50 per cent of quartz grain surface has been reformed.