陆缘和陆内前陆盆地主要特征及含油气性研究

Geological characteristics and hydrocarbon potential between epicontinental and intracontinental foreland basins

依据前陆盆地的发展演化、剖面结构、层序关系和生储盖组合特点 ,将前陆盆地划分为陆缘前陆盆地和陆内前陆盆地两大类 ,其中陆缘前陆盆地包括周缘前陆盆地和弧后前陆盆地。它们之间的主要区别表现在 :( 1)从盆地构造演化上看 ,陆缘前陆盆地经历了裂谷被动边缘或弧后裂谷阶段 ,陆内前陆盆地则缺乏这一阶段 ;( 2 )从盆地层序结构上看 ,陆缘前陆盆地下伏海相被动大陆边缘层序或弧后裂谷层序 ,陆内前陆盆地一般缺失海相层序 ;( 3 )从成因机制上看 ,陆缘前陆盆地与碰撞造山或弧后造山作用有关 ,陆内前陆盆地则主要与造山期后碰撞带再旋回活动有关 ;( 4 )从烃源岩发育特征上看 ,陆缘前陆盆地发育海相和陆相烃源岩 ,陆内前陆盆地主要形成陆相烃源岩。由此可见 ,这两类盆地的地质特征和含油气性有明显区别。

According to the tectonic evolution,structure of section,sequence relationship and source-reservoir-cap composition of foreland basins,the foreland basins can be divided into two types including epicontinental foreland basin and intracontinental foreland basin.The former includes peripheral foreland basin and retro?-arc foreland basin.There are some differences between the two types of foreland basins:(1) The epicontinental foreland basin went through passive continental margin or retro?-arc rift stage during tectonic evolution stage,but the intracontinental foreland basin lacked this period.(2) For the texture of sequences,the tectonic-sequence of the epicontinental foreland basin lain on the marine passive continental margin sequence or retro?-arc rift sequence,and the intracontinental foreland basin lacked of marine sequence in generally.(3) On the genetic mechanism,the forming of the epicontinental foreland basin was related to the collided orogenic belt or retro?-arc orogeny,and the intracontinental foreland basin was related to the rejuvenated orogenic belt.(4) On the characters of hydrocarbon development,the epicontinental foreland basin developed marine and non-marine source rocks,and the intracontinental foreland basin mainly developed non-marine source rocks.The differences of geological characteristics and hydrocarbon potentials between the epicontinental foreland basin and intracontinental foreland basin are obvious.