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.