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东北北部二叠系比较发育,分布广泛,蕴藏有铁、锰、磷、石灰石等矿产。研究二叠系各组特征,特别是其中以火山岩为主的组,对于本区二叠系的划分、对比和逐步认识东北北部二叠纪岩相古地理及古火山活动,进而指导寻找有关矿产,均有其理论和实际意义。大河深组是吉林省中部早二叠世早期大规模火山活动的产物,广泛分布于桦
The Permian in northeastern North China is relatively developed and widely distributed, possessing such minerals as iron, manganese, phosphorus and limestone. To study the characteristics of each group in the Permian, especially the volcanic-dominated ones. For the division, comparison and understanding of the Permian lithofacies palaeogeography and ancient volcanic activity in the northern part of the North China, , Both have their theoretical and practical significance. The Dahe Formation is a product of large-scale early volcanic volcanic activity in the central part of Jilin Province during the Early Permian period and is widely distributed in Betula