内蒙古乌兰浩特沙巴尔吐地区上二叠统林西组重新划分

本文作者在内蒙古乌兰浩特北沙巴尔吐一带开展1∶5万区调时,根据岩石组合、古生物特征、沉积环境等对出露于该地区扎格斯台一带的一套黑色砂板岩进行了重新厘定。重新厘定后的林西组为一套黑色板岩、粉砂岩夹细砂岩地层组合,具陆相沉积特征。该套地层在原1∶20万区调工作中被划归索伦组(P_(1~s)),原1∶25万区调又将其划归哲斯组(P_(2~(zs))),本次将上部陆相碎屑岩部分重新厘定为上二叠统林西组。该地层的重新厘定对本区寻找烃源岩有重要的指导意义。

Redivision of the Upper Permian Linxi Formation in the Shabaertu region, Ulanhot, Inner Mongolia

A succession of black sandstones and slates cropped out in the Shabaertu region, Ulanhot, Inner Mongolia was redivided and assigned to the Linxi Formation during the 1:50 000 regional geological survey in 2016-2018 according to lithology, palaeontology and sedimentary environments. The newly established Linxi Formation consists of black slates and siltstones intercalated with fine-grained sandstones characteristic of continental deposits. These strata were previously involved into the Lower Permian Suolun Formation (P₁s) in the 1:200 000 regional geological survey in 1965, and into the Middle Permian Zhesi Formation (P₂zs) in the 1:250 000 regional geological survey in 2008-2011. In this study, the upper continental fine-grained clastic rocks of the Zhesi Formation are redivided into the Upper Permian Linxi Formation. The redivision of these strata may be significant to the hydrocarbon exploration in the study area.