孤北洼陷孔店组与沙河街组四段的多重地层划分

对孤北洼陷孔店组、沙四段生物、岩石、电性及地震地层等多重地层划分进行详细的研究,研究结果表明孔三段属灰紫色冲积产物,孔二段发育典型的暗色泥岩,沙四下亚段为红色砂、泥岩,沙四上亚段主要是灰色泥岩,夹有砂岩;电测结果表明:进入沙四下亚段时电阻率曲线相应抬起,沙四上亚段整体是一个低阻段,沙四段顶界划在下斜坡电阻的底部。孤北洼陷地层划分时要注重多重地层划分的方法,单一资料用于划分地层难于反映真实面貌。

MULTIPLESTRATIGRAPHIC DIVISION OF THE KONGDIAN FORMATION AND THE MEMBER 4 OF SHAHEJIE FORMATION IN THE GUBEI DEPRESSION

Based on the study of the paleontologic, lithological, electrical, seismic stratigraphic features of the Kongdian Formation and the Member 4 of the Shahejie Formation (Sha4), a detailed study of the multiple stratigraphic division was made. And the research results are applied to the practice of logging field, showing that the Member 3 of Kongdian Formation(Kong3) is composed of purple alluvium, the Member 2 of Kongdian Formation(Kong2) consists of typical dark-colored mudstone, the Lower Submember of Sha4 is formed chiefly of grey mudstone intercalated with sandstone. The results of electric logging indicate that when entering the Lower Submember of Sha4, electric resistivity carves rise correspondingly and the Upper Submember of Sha4 is, as a whole, a low resistivity member. The top boundary of Sha4 is placed at the basal part of the lower slope electric resistivity. It is pointed out at the same time in this paper that during the stratigraphic division of the Gubei Depression, much attention must be paid to the methods for the multiple stratigraphic division and it is difficult to reflect true aspect if only using a single method to divide strata.