冀辽裂陷谷中上元古界构造特征及演化

THE TECTONIC EVOLUTION OF MIDDLE AND DPPER PROTEROZOIC ERATHEM IN JILIAO AULACOGEN

在区域地质构造研究的基础上,本文以地球动力学的观点系统地分析了中上元古界构造特征和演化。中上元古界构造经历了中晚元古代裂陷谷-坳陷构造发展阶段、古生代和三叠纪升降运动构造发展阶段、侏罗白垩纪强烈活化构造阶段和新生代晚期活化阶段。晚印支运动造成全区挤压构造的基本格局,燕山运动多次拉张和挤压脉动交替使之受到强烈的改造和复杂化。早第三纪同生正断层的张裂活动又使中上元古界大幅度掀斜,甚至使一些构造变成单斜挠曲。东营期末,本区构造最后定型。晚第三纪,本区张裂活动基本停止,南部地区整体下沉。大地构造的演化,特别是中新生代的块断作用及其活化历史对于本区油气藏的形成和保存具有重要的影响,并且是一个控制性的因素。

On the basis of the study on regional tectonic, the tectonic evolution of middle and upper Proterozoic tectonost ratigraphic unit has been systematically analyzed. The structures of middle and upper Proterozoic strata experienced four major stages; the stage of aulacogen-depre ssion in middle and late Proterozoic, the stage characterized by up and down movement of platform in Paleozoic and Triassic, the stage marked by intensive reactivation in Jurassic and Cretaceous and the stage of late reactivation in Cenozoic.The late Indosinian movement led to I lie formation of fundamental framework of eornpressional folding structures, These structures were intensively reformed and complicated by Yanshaman movement, cspecialy the second episode. The contemporcaneous normal faults with listric fault surface of paleogene caused the vigorous tilting of fault blocks with certain structures even deformed as monoclinal flexures. The movement, at the end of Dongying period finally shaped the structres in this area. Since then, the faulting has basically ceased, the southern part of this area subsided as a whole. The tectonic evolution especially the tectonic reactivation during the Mesozoic and Cenozoic is of important influence and is one of the controlling factors for the formation and preservation of oil and gas pools.