漠河盆地中生代地层层序及时代

依据近几年地层研究成果和野外地质调查获得的新资料 ,对漠河盆地中生代地层进行了厘定 ,将阿杭提河组划归绣峰组 ,木瑞组划归上库力组下部 ,上库力组和依列克得组之间的含煤地层划归上库力组上部。这样纵向上塔木兰沟组—上库力组—依列克得组为火山岩—碎屑岩夹火山岩、煤层—火山岩旋回 ,与邻区具有很好的对比关系。依据新的同位素资料 ,将塔木兰沟组的时代厘定为早白垩世 ;依据双壳类、腹足类、介形类、植物、孢粉等化石资料 ,对漠河盆地额木尔河群的时代进行了讨论 ,认为额木尔河群的时代为晚侏罗世。

SEQUENCE AND AGE OF THE MESOZOIC STRATA IN THE MOHE BASIN

The Mesozoic strata in the Mohe Basin have been collated on the basis of the recent stratigraphic research and field geologic survey. Therefore the Ahangtihe Formation is incorporated into the Xiufeng Formation, Murui Formation into the lower part of the Shangkuli Formation, and the coal bearing beds between the Shangkuli and the Yiliekede Formation into the upper part of the Shangkuli Formation. The sequence of the Tamulangou, Shangkuli, and Yeliekede Formations displays vertically the cycles of volcanics—clastics intercalated with volcanics and coal beds—volcanics and may be well correlated with strata of the neighboring regions. According to new isotopic data, the age of the Tamulangou Formation is Early Cretaceous. Also, the age of the Emuerhe Group in the basin is discussed and then considered as Late Jurassic based on fossil bivalves, gastropods, ostracodes, plants and sporo pollen collected in this sequence.