论文部分内容阅读
民和盆地侏罗系所产生物化石可划分为4个生物化石组合，2个亚组合。它们分别分布于下侏罗统大西沟组、中侏罗统窑街组、上侏罗统上部享堂组和大通河组下部。2个亚组分布于中侏罗统窑街组一段和窑街组二段。据上述古生物化石的4个分布组合，划分侏罗系下界位于大西沟组与元古界灰绿色千枚岩或白云岩化大理岩之间；下、中侏罗统的界线在大西沟组与窑街组之间；中、上侏罗统的界线在窑街组与享堂组之间；侏罗系上界暂定在大通河组下部与中部之间。
Fossils from the Jurassic in the Minhe Basin can be divided into four fossil assemblages and two sub-assemblages. They are distributed in the Lower Jurassic Daxigou Formation, Middle Jurassic Yaojie Formation, Upper Upper Jurassic Upper Dangtang Formation and Datonghe Formation. Two subgroups are located in the first section of the Middle Jurassic Yaojie Group and the second section of the Yaojie Group. According to the above four assemblages of paleontology fossils, the lower Jurassic interval is divided between the Daxigou Formation and the Proterozoic gray-green phyllite or dolomitization marble. The boundary between the Lower and Middle Jurassic in the Daxigou Formation and Yaojie group; middle and upper Jurassic boundaries in the Yajie group and enjoy the group between the upper boundary of the Jurassic tentatively in the lower part of the Datonghe Formation and the middle.