松辽盆地北部变换构造及其石油地质意义

TRANSFORM STRUCTURES IN NORTHERN PART OF SONGLIAO BASIN AND ITS SIGNIFICANCE IN PETROLEUM GEOLOGY

松辽盆地北部变换构造包括交换断层和变换带。变换断层与正断层系直交或斜交。变换带包括同向超接、伺向平行、同向趋近、共轭发散超接、共轭会聚超接及共轭平行六种。变换断层由基底先存断层活化或薄弱带活化所造成。它们对断陷盆地轴向构造变化起控制作用，对沉积物和油气分布有重要影响。

Transform structures in the northern part of Songliao Basin include transform faultsand transform zones. The transform faults are orthogonal to or obligue to normal faults.Their geometric forms were largely determined by the geometric forms and displacementso f the normal faults that controlled thd depression. The faults, resulted from the activationo f the pre-existing faults or weak belts on the basement, were the fundamental factor thatdivided fault-depressed basins into blocks from south to north, and discontinuous in axis.Transform zones are structural systems which adjusted extensional deformation during theevolution of rift-basin. The transform zones could be divided into synthetic collateral,synthetic overlap, synthetic approach, conjugate divergent, conjugate convergent and conjugate collateral types. All of the above mentioned faults, zones and normal faults formedin rifting stage.