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为了示踪渤海湾盆地石臼坨凸起西南陡坡带扇三角洲源汇体系,对其东三段层序(Ed3)的6个砂岩样品进行碎屑锆石U-Pb定年分析.西部扇体(C6-4-4井)富含白垩纪(K)锆石并具有110 Ma峰值,母岩以白垩系义县组火成岩为主;中部(C6-4-3、C6-4-6D井)、东部扇体(C6-4-5D)富含侏罗纪(J)锆石并具有152Ma或168Ma峰值,母岩以侏罗系蓝旗组火成岩为主,古生代(Pz)锆石则来自中生界碎屑岩.所有样品都含有太古代(Ar)、元古代(Pt)锆石,母岩为花岗岩基底.研究表明,除古生界碳酸盐岩外,源区的母岩地层均可通过碎屑锆石U-Pb年龄示踪,各扇体物源的差异性是由母岩地层倾向控制的,由于中生界向西北倾斜,白垩系主控西部扇体沉积,侏罗系则是中部、东部扇体的主要物源区.
In order to trace the fan delta source-sink system in the southwestern steep slope of the Shijiu Tuo Tu uplift in the Bohai Bay Basin, detrital zircon U-Pb dating of six sandstone samples from the Ed 3 of the East Third Member of the basin was analyzed. -4-4 wells) are rich in Cretaceous (K) zircons and have a peak value of 110 Ma. The parent rocks are mainly igneous rocks in the Cretaceous Yixian Formation. In the middle (C6-4-3, C6-4-6D wells), eastern The fan body (C6-4-5D) is rich in Jurassic (J) zircon and has a peak value of 152Ma or 168Ma. The parent rocks are dominated by Jurassic Lanqi igneous rocks and Paleozoic (Pz) zircons are derived from Mesozoic All samples contain Ar, Proterozoic (Pt) zircon and the parent rock is granite basement.The study shows that except the Paleozoic carbonate rocks, the parent rock strata in the source area can pass Detrital zircon U-Pb age tracing, the source of each fan body is controlled by the pro-forma stratum. Because the Mesozoic is inclined to the northwest, the Cretaceous hosts the western fan body and the Jurassic is Central, Eastern fan of the main source area.