河北平原东半部钻孔岩心中粘土矿物的电子显微镜研究

Six clay mineral phases are recognized by means of electron microscope examination in a drilling profile in the eastern part of the Hobei Plain. Based on the relationship between these clay mineral phases, strata in this profile are divided into two groups, i.e., the upper and the lower groups. Five subgroups can be further distinguished within the lower group. The evolution of clay mineral phases provides indication of %he palaeoclimatic variation during this geological period.