摘要
通过层序界面的识别和划分,乌南凹陷下白垩统可划分为5个二级层序,7个三级层序。以断裂坡折带为界,乌南凹陷可划分为西缘陡坡带、东缘斜坡带、乌南次洼带、乌中低凸起、巴彦塔拉断裂带等次级构造单元,各次级构造单元对沉积体系的发育分布具有重要的控制作用。根据沉降史的分析,下白垩统可划分为裂陷初期、裂陷早期、裂陷中期、断-拗转换期和拗陷期5个构造演化阶段,分别发育火山岩-冲积扇盆地层序、冲积扇-浅湖盆地层序、深湖-半深湖盆地层序、半深湖盆地层序和浅湖盆地层序,各二级层序的发育演化和沉积相构成受构造演化的控制。东缘斜坡带和巴彦塔拉断裂带附近是有利储集相带。
According to the recognition and division of the sequence boundaries,the Lower Cretaceous of Wunan depression can be divided into five two-order sequences and seven third-order sequences.Wunan depression is composed of western steep slope zone,eastern gentle slope zone,Wunan sag,Wuzhong uplift and Bayantala fault zone.Each sub-structural unit constrains the development and distribution of sedimentary systems.The tectonic subsidence analysis suggests that the evolution of the Wunan depression can be divided into five stages: early rifting stage,initial rifting stage,intense rifting stage,rifting-subsiding stage and subsiding stage.Alluvial-volcanic basin sequence,alluvial-shallow lacustrine basin sequence,semi-deep lacustrine-deep lacustrine basin sequence,semi-deep lacustrine basin sequence and shallow lacustrine basin sequence are developed respectively.The evolution and sedimentary facies of each two-order sequence was controlled by the different stages.The slope region in the east and the Bayantala fault zone are the favorable reservoir belts.
出处
《现代地质》
CAS
CSCD
北大核心
2010年第4期669-677,共9页
Geoscience
基金
国家自然科学基金项目(40972081)
关键词
层序地层
沉积体系
构造沉降
乌南凹陷
sequence stratigraphy
sedimentary system
tectonic subsidence
Wunan depression