准噶尔盆地莫西庄地区侏罗系三工河组层序地层学研究

应用Vail经典层序地层学的理论和方法,综合利用测井、岩芯、地震、野外露头等资料,对准噶尔盆地莫西庄地区侏罗系三工河组层序边界、三级层序内的最大湖泛面和初始湖泛面进行识别,划分出2个三级层序(Jsq1和Jsq2),每个三级层序又划分为3个体系域,即低位体系域、湖侵体系域和高位体系域。对准层序、准层序组进行识别,划分19个准层序,分别对应19个小层,对5口单井进行层序划分,在横向上进行连井层序对比。对2个三级层序的地层特征进行研究,在此基础上,研究三工河组层序形成的主要控制因素。研究结果表明:构造活动是层序形成的主要控制因素;沉积物供给条件和气候变化对层序形成有较大的影响,湖平面的变化是构造沉降、气候变化、沉积物供给等因素的综合反映。

Sequence stratigraphy of Jurassic Sangonghe Formation in Moxizhuang Area, Junggar Basin

Using the theories and methods of Vail classic sequence stratigraphy,logging,drilling core,seismic,outcropping data of Jurassic Sangonghe Formation in Moxizhuang Area of Junggar Basin were analyzed to identify sequence boundary,maximum flooding surface and first flooding surface of third-order sequence.The formation was divided into two third-order sequence(Jsq1,Jsq2),and each sequence was divided into three system tracts,i.e.low system tract,transgressive systems tract and high system tract.Parasequenc and parasequence set were identified,the formation was subdivided into 19 parasequences,which were corresponded to 19 sublayers;5 wells sequence was divided,and sequence stratigraphic framework was established.The character of each sequence was analyzed,and the main controlling factors of the sequence formation was studied.The results show that tectonic activity is controlling the factor of the sequence formation main,sediment supply conditions and climate change have great impact on the formation of the sequence,and lake level change is a comprehensive reflection of tectonic subsidence,climate change,sediment supply and other factors.