“盆”“山”耦合和脱耦:进展,现状和努力方向

OROGENY AND COUPLED/DECOUPLED BASIN DEVELOPMENT:A REVIEW

“盆”“山”耦合和脱耦是在盆地研究发展到一定阶段后,中国地质学家立足于复合大陆上油气勘探的大量经验和教训而提出的含油气盆地研究新理论。这一研究主要表现为从“山”到“盆”,文章简要回顾了其形成的2个阶段(分别以内硅铝质的和内硅镁质的造山作用为主要研究对象),概要总结了耦合研究的3个重点方向(对盆地成因、沉积作用和盆地发育过程的制约)和脱耦的3种可能后果(盆地闭锁、盆地破坏、盆地遭受改造油气发生晚期次生成臧)及其运动学;也扼要介绍了从“盆”到“山”研究的主要成果。文章提出下一步的努力方向是:理论上充实和完善“中国型盆地”的发育演化模式,实践上是通过3方面的努力(开创盆地研究新阶段,指导生储盖组合和圈闭的研究,结合流体动力学的研究探讨油气运聚规律)使之真正成为中国大陆上油气勘探的理论指导。

In the 1990s the progress of basin study abroad is symbolized by b as in modeling, basin dynamics and coupling of lithosphere and near-surface proces ses. Meanwhile, many Chinese geologists, based upon the works on the Chinese con tinent-a composite continent, and by summing up the experience accumulated duri ng the practice in oil-gas exploration, advanced a new theory for petroliferous basin study, namely, orogeny and coupled/decoupled basin development. Mainly, t he theory has expanded the scope of study about the geologic process from orogen to basin, and rendered some helps in the understanding about basins in light of works on orogen. The paper briefly looks back on the two phases for the geologi cal process from orogen to basin and introduces some of the key achievements mad e in related study. Here the ensialic (intracontinental) and ensimatic orogenies were studied in both of the earlier and later phases. It is revealed in this pa per that the later phase is characterized by at least five points, i.e., the oro geny-coupled basins including both the marginal and the interior (intracratonic ) ones, the regional orogen-basin coupling systems being recognized preliminari ly, a systematic study on the kinematics of orogen-basin coupling, an initial e xploration about geodynamics, and inheritance or decoupling of the coupled relat ion as constructed by the Indosinian orogeny. Three key aspects (the orogeny-re lated basin formation, sedimentation and basin development) and three possible c onsequences of decoupling (basin locking, basin breakage, basin reformation and secondary accumulation of hydrocarbons) were generally pointed out for the oroge n-basin coupling study. It is also demonstrated that efforts for the next step should be focused on two major areas: theoretically, to substantiate and perfect an evolution model of the Chinese-type basin, and practically, to become a gui dance for oil-gas investigation on the continent, and may cover the following t hree aspects: to usher in a new epoch of basin research, to provide guidance on the study about source-reservoir-cap rocks and trap, and to explore the laws g overning oil-gas migration and accumulation by integrating results of fluid dyn amic research.