二连盆地白音查干凹陷构造特征与油气勘探方向

STRUCTURAL FEATURES AND DIRECTION IN PETROLEUM EXPLORATION OF THE BAIYINCHAGAN HOLLOW OF THE ERLIAN BASIN

二连盆地白音查干凹陷的伸展量在5.4—9.2km之间。构造沉降量变化很大,在65—1082m之间。其主要活动期是在阿尔善组(K_1)及腾格尔组(K_1)沉积时期。以114Ma(T_3)为界,凹陷具有两个性质截然不同的发育期,在剖面上,它是由上部坳陷与下部断陷组成。在平面上,分东部洼陷与西部洼陷,其构造活动东西有明显差异,主要表现在西早东迟、西强东弱。主要油气远景在西部洼陷的北部陆坡带。

The amount of extension ranges from 5.4 to 9.2 kilometers and the amount of structural subsidence from 65 to 1082 meters in the Baiyinchagan (BYCG) hollow of the Erlian basin.The main stage of structural activity occurred during the stage of deposition of the Alxa Formation (K_1) and Tengger Formation (K_1).The dividing line of 114 Ma (T_3) separates the development of the hollow into two different development stages.In section,it is actually composed of a depression in the upper part and a faulted depression in the lower part.In plan,it may be divided into the east and west depressions.The structural activity shows marked difference in the two depressions,which is mainly mainly manifested by the fact that the structural activity occurred earlier and strongly in the west and later and weakly in the east.The main petroleum prospects exist in the northern steep slope zone in the western depression.