松辽盆地北部裂后反转期层序地层格架及其形成机制

应用高精度层序地层学分析的原理和方法, 通过对研究区新处理的区域性地震反射剖面、测井和岩心等资料的综合分析, 建立了松辽盆地北部裂后反转期层序地层格架.通过盆地的充填记录、湖平面变化和区域演化等信息, 论证了松辽盆地裂后反转期各级界面的地质属性, 分析了其形成机制, 建立了盆地的沉积演化过程模型.研究表明, 盆地裂后反转期发育的一级界面SB02和二级界面SB03、SB11均是区域构造挤压事件的响应界面; 而湖平面的变化和物源供给导致了三级层序体系域构成样式的多样化; 嫩江组二、三段识别出的7个四级层序则是在三级湖平面旋回的高位稳定期盆地物源充足、沉降速率较低的条件下形成的.本研究为松辽盆地中浅层隐蔽油气勘探提供了重要的等时地层对比格架. 

Sequence Stratigraphic Framework and Its Formation Mechanism of Post-Rift Inversion Successions in North of Songliao Basin,China

The principle and method of high resolution sequence stratigraphy are employed to deal with seismic reflection profiles, well logs and core data. The sequence stratigraphic framework of post-rift inversion successions has been reconstructed in north of Songliao basin. According to the information of basin fillings, lacustrine level changes and regional tectonic evolution, the geological property and formation mechanism of sequence boundaries are analyzed. The sedimentary filling evolution model is built in post-rift inversion successions. The study indicates that both the 1st-order unconformity SB02 and the 2nd-order ones SB03/SB11 in post-rift inversion successions are responding surfaces to regional compression tectonic events. The styles of systems tracts in the 3rd-order sequences are controlled by lacustrine level changes and provenance supply. The 7 4th-order sequences identified in the second and third members of Nenjiang Formation formed under the conditions of enough provenance and low tectonic subsidence rate during the highstand systems tract of 3rd-order lacustrine level cycle. An important isochronous stratigraphic architecture has been provided for exploration of subtle reservoir in the middle-shallow layers in north of Songliao basin.