欧亚大陆中部盆地群大剖面的编制及其构造意义

Characteristics of the Basins from the E-W Inter-continent Profile in Central Eurasia

盆地结构记录了盆地演化特征,盆地群结构和构造特征由其所处的构造背景和板块边界决定。随着油气勘探的不断深入,积累了大量地震剖面,为盆地群剖面特征对比,提供了大量的基础资料。本文从大地构造背景着手,通过筛选地震与地质剖面,大致沿北纬39°绘制了欧亚大陆东西向剖面(在东部北黄海盆地有向南的偏转):西起黑海盆地,东至琉球海沟,剖面长约12000km,横穿18个盆地,涵盖克拉通盆地(塔里木原型盆地等)、裂谷盆地(太原盆地、渤海湾盆地等)、前陆盆地(黑海盆地、南里海盆地等)和弧后盆地(东海盆地)等多种盆地类型。其中,陆壳上的盆地发育在前寒武基底上,演化历史悠久;褶皱基底、洋壳基底和洋陆过渡壳基底上发育的盆地主要发育在中新生代。通过详细对比剖面各段结构和构造演化特征,发现中新生代构造活动决定了欧亚大陆中部盆地群最终格架,盆地多具有多期叠合改造的特征。剖面西段盆地群普遍具有中生代伸展断陷,叠加后期挤压坳陷的特征;剖面东段盆地群具有中生代断陷,叠加后期坳陷的特征。现今构造格架由西到东表现为前陆坳陷到弧后坳陷,鄂尔多斯盆地和沁水盆地是本剖面线结构特征分段的枢纽。

Basin＇s structure records its evolution,and can be decided by the tectonic backgrounds and plate boundaries.As the increasing exploration in oil and gas,lots of seismic sections have been accumulated.This provides a large number of basic data for the comparison of the characteristics of the basins.Beginning from the tectonic backgrounds and selecting seismic profiles,this article draws E-W intercontinent profile in central Eurasian,mainly along N39°（turning southward in the East）.The profile begins from the Black Sea basin in the west and ends to the Ryukyu trench in the east.The profile is about12000 km long,crossing 18 major basins,covering the cratonic basin,rift basin,foreland basin and forearc basin.Among the basins,history of the evolution of the basins on the cratonic basement is longest.Otherwise,the Corridor basins and Central Eurasia basins were developed on the late Paleozoic folding basement.The Meso-Cenozoic tectonic events decided the final tectonic frame of the basin groups.Basins have superimposed features：basins in west of the profile experienced Mesozoic rift and superimposed late foreland depression.Basins in east of the section experienced Mesozoic rift and superimposed later foreland depression.The current tectonic frame from west to East is foreland depression to back-arc depression,with Ordos Basin and Qinshui basin in hinge of the section.