内蒙古大梁道班地区本巴图组地层时代的确定及其地质意义

内蒙古大梁道班地区本巴图组出露面积较广,被岩浆活动和构造运动改造破坏,地层变形强烈,普遍发育轻微变质,导致岩石组合类型复杂多变,地层层序不清,构造样式混乱,与区域上本巴图组有显著差异。通过对该套地层岩石组合的梳理、同位素年龄测定和生物化石的分析利用确定本区地层的时代为晚二叠世,并根据其构造变形特征结合研究区大地构造背景研究可以侧面证明西伯利亚和华北二大版块在二叠纪晚期-三叠系初完成拼合。

AGE DETERMINATION OF BENBATU FORMATION AND THE GEOLOGICAL SIGNIFICANCE OF DALIANGDAOBAN,INNER MONGIOLIA

The Benbatu Formation take large area of Daliangdaoban in Inner Mongolia. They deform intensively and metamorphose lightly caused by magma movement and tectogenesis, therefore, there are complex rock combination types and blurry stratum sequence with jumbled structure which are different with the regional Bumbat Formation. We found the stratum were developed in late permian system according to the reseach on the rock combination and isotopic age testing as well as the analysis of fossil organism. They also found that the Siberia plate joint North China plate at late Permian period and early Triassic System.