目前地学界普遍认为低角度断陷盆地是由低角度正断层拆离形成的,具有上拆离裂离和上拆离斜坡两种成因模式.介绍、评论了5种低角度正断层成因模型.以珠江口盆地恩平低角度断陷为例,通过三维地震解释以及平衡剖面恢复,提出了一种新的模式——先存低角度逆断层负反转成因模式.认为不同成因的盆地具有不同的结构特征,低角度上拆离断陷盆地湖盆浅且无裂后沉积,低角度负反转断陷盆地湖盆深并且裂后沉积厚度大,前者往往不具备勘探价值,而后者的勘探潜力巨大.

Up to now, in the geological community, it is generally believed that the low-angle rift basin was formed by low-angle normal detachment fault, and it can be divided into two genetic models: supradetachment breakaway model and supradetachment ramp model. In this paper five kinds of genetic models of low-angle normal fault are introduced and reviewed. Taking Enping low-angle fault depression of Pearl River Mouth Basin as an example, based on the 3D seismic profile interpretation and balanced cross-section restoration, this paper proposed a new model: negative reversion took place after the pre-existing low-angle reverse fault. It is shown that the different genetic basins have different structural characteristics. Low-angle supradetachment basin with shallow lake experienced minor post-rift subsidence, while low-angle negative reversion fault basin with deep lake underwent prominent post-rift subsidence, and the former tend to have no exploration potential, but the latter has a huge exploration potential.