Vertically, coal distributes in Permo-Carboniferous and Jurassic; oil and uranium distributes mainly in Jurassic while gas distributes in Ordovician and Permian.
在纵向上，煤聚积于石炭—二叠系和侏罗系，石油和铀矿主要分布在侏罗系，天然气则储集在奥陶系和二叠系。
2
The rock samples of the Permo-Carboniferous system in Hebi Area were collected and an ICP-MS method was used to analyze the rare earth elements of the samples systematically.
采集了鹤壁地区石炭-二叠系岩石样品，采用电感耦合等离子质谱技术对样品进行了系统的稀土元素测试分析。
3
The Xingtai mining area is a typical North China Permo-Carboniferous karstic type coalfield, its lower coal group is generally under threat from the thick Ordovician limestone strong karstic aquifer.