柴达木北缘西段侏罗纪盆地构造特征及其演化

柴达木北缘西段侏罗系的展布受北西向和近东西向两组构造的控制,近东西向构造对侏罗系具有南北分带作用,北西向构造对侏罗系具有东西分块的作用,两组构造使得侏罗系存在多个厚度中心。早、中侏罗世,该区为伸展断陷盆地,沉积了重要的烃源岩系;晚侏罗世—白垩纪为挤压盆地。从早侏罗世到白垩纪,盆地沉积具有由南向北、由西向东迁移的特征。叠合其上的新生代盆地沉积对侏罗系具有重要的保存作用,促进了烃源岩有机质向油气的转化。新生代的构造变形及其组合特征为该区油气成藏提供了条件。 

STRUCTURAL CHARACTERISTICS OF THE JURASSIC BASIN IN THE WEST PART OF THE NORTHERN MARGIN OF THE QAIDAM PLATE AND THEIR EVOLUTION

The Jurassic distribution was controlled by NW-trending and near EW-trending structures in (the west part of the northern margin of the Qaidam Plate. Near EW-trending structures zoned the Jurassic- from north to south, and NW-trending structures divided the Jurassic into some blocks from west to east. Several thickness centers formed because of the controlling of NW-trending and near EW-trending structures. The Early-Middle Jurassic basin was an extensional faulted basin, in which major hydrocarbon source rocks were deposited. And the Late Jurassic-Cretaceous basin was a compressional basin. From the Early Jurassic to the Cretaceous, strata deposition migrated from south to north and from west to east. The deposition of the Cenozoic basin superposed on the Jurassic basin played an important role in the pre-servation of the Jurassic, and promoted oil and gas generation. Structure deformation and combination of the Cenozoic provided favorable conditions for the oil and gas pool formation of the study area.