四川盆地加里东古隆起的构造机制和成藏模式

乐山-龙女寺古隆起为四川盆地加里东期古隆起的主体部分,根据对震旦系顶面、寒武系顶面,中奥陶统顶面和阳新统底面构造的分析,古隆起分为两部分:西部为简单背斜,东部为复式构造带,构造应力均为挤压型.以地质力学原理为基础,认为古隆起的构造特征是在地球自转速度降低的情况下,受纬向和经向惯性力作用的结果,由此而形成的分段不对称褶皱就是古隆起的构造成藏模式,并根据此模式指出了寻找大中型油气藏的有利区块.

TECTONIC MECHANISM AND POOLING MODEL OF THE CALEDONIAN PALEOSWELL IN THE SICHUAN BASIN

Leshan-Longnusi Paleoswell is the main body of the Caledonian Paleoswell in the Sichuan basin.According to analyses on the structure of the Sinian,the Cambrian and the Middle Ordovician superfaces and the Lower Permian subface,the paleoswell is divided into two parts with compressional structural stress,the simple anticline in the western part and complex structural belt in the eastern part.Based on the principle of geomechanics,it is considered that the tectonic characteristics of the paleoswell are the effect of latitudinal and meridional inertial force subjected when the Earth,s rotational speed decelerated.And sectional asymmetric fold formed is just the tectonic pooling model of the paleoswell.In accordance with the model,the advantageous districts for large and middletyped oil/gas accumulation are indicated.