“盆”“山”耦合和脱耦在含油气盆地分析中的应用

OROGENY AND COUPLED/DECOUPLED BASIN DEVELOPING：APPLICATION IN PETROLIFEROUS BASIN ANALYSES

吴根耀 马力

WU Gen-yao MA Li

中国科学院, 地质与地球物理研究所, 北京, 100029 2. 中国石化集团公司, 江苏油田, 江苏, 扬州, 225009

Institute of Geology and Geophysics, Chinese Academy of Sciences, Beijing 100029, China 2. Jiangsu Oilfield, SINOPEC, Yangzhou, Jiangsu 225009, China

本文旨在汲取前人关于盆地研究的思想成果的基础上,从"盆""山"耦合和脱耦的角度理解这些盆地的成因和特征,进而完善和深化对含油气盆地的认识.所谓继承型叠合盆地,是原"盆""山"耦合关系至今仍未解脱;延变型叠合盆地则是原"盆""山"关系脱耦时发生闭锁.造山作用与盆地发育间有着统一的运动学过程和动力学机制,叠合盆地的本质是"盆""山"系统的更迭.造山过程的各个阶段都有复合盆地发育,某些原视为复合盆地的构造盆地实际上是由若干个原本不相连的盆地内的沉积经多期构造作用移位后拼凑出来的沉积物拼盘,必须对之进行构造复位.中国油气资源二次创业的成功取决于对残留盆地认识的飞跃,因而"盆""山"耦合和脱耦是今后中国大陆及邻近海区盆地研究的新思路,是指导油气勘探的探索之路.

Chinese geologists had a correct understanding of some specific characteristics on petroliferous basins in China continent,and named them superimposed basin,composite one,reformed one,residual one,relict one,etc.The paper aimed to deepen our comprehensions on the basins' mechanics and features in the light of orogeny and coupled/decoupled basin developing.The creation of inheritance-type of superimposed basin,with the Junggar Basin being an example,was caused by a "basin"-"orogen"relation constituted in the Hercynian orogeny keeping on during Meso-Cenozoic,not decoupled so far.If a "basin"-"orogen"relation setting up in the Indosinian orogeny decoupled and a part of cratonic area locked in the Yanshanian or Himalayan movement,the part could be classified into alteration-type of superimposed basin.Taking the Sichuan,Ordos and Tarim Basins as an instance,the locked conditions were analysed thoroughly.The essence of basin superimposition should be a replacement of "basin"-"orogen"system.Some possibly complicated cases of replacement of "basin"-"orogen"system were discussed in the paper.Composite basin might occur in every stage of an orogenic process.Some so called "composite basin",for example,the Chuxiong Basin in Yunnan,might be a sediments' collage,which resulted from migration and collage of sediments originally in varied basins by multiple orogenies.Residual basin was different from relict basin which was a prototype one.To study a residual basin,the key problem might be mode or style of basin reformation,and then the conditions for secondary hydrocarbon generation in later period.A new leap of oil-gas exploration in China would depend on new progresses of understanding on the residual marine basins in age of Paleozoic and Early-Middle Triassic;and the leap of oil-gas exploration would carry on within a new theoretical frame.The orogeny and coupled/decoupled basin developing,dealing with a uniform kinematic process and geodynamic mechanics between "basin" and "orogen",would play an important role in the new leap.

https://doi.org/10.11781/sysydz200306648