Study Of Wulashan Group Graphite Mine In The Northern Region Of Baotou Inner Mongolia

Northern region of Baotou Inner Mongolia located in northern margin of North China platform.The area is affected by multi-phase metamorphism,and mature highgrade metamorphic rocks of the Wulashan group with New Archaean age.This Highgrade region possess geological metallogenetic conditions of graphite formation of regional metamorphism type.In conclusion,research on graphite formation and the ore beds in this region has practical significance.This paper is based on the full collection and analysis of previous research results,and geological mapping of large scale.Unequal graphite mineralization was found in Al rich gneiss and granulite formation of Wulashan group in this region.Graphite formation beds have a character of low resistance high pol what can be proved by(1∶10 000)induced polarization intermediate gradien survey,the IP anomaly and the graphite mineralization above-ground are highly matched.The graphite ore bodies occur in Diopside gneiss group,Garnet biotite gneiss group and Biotite plagioclase gneiss group of Wulashan.The host rocks are garnet biotite gneiss,sillimanite garnet biotite gneiss and diopside plagioclase granulite.The roof and floor rocks include Al rich gneiss,granulite,diopside marble and quartzite which have originality components are sandstone,siltstone and carbonatite.They have the typical metamorphic sedimentary assemblage characteristics.The ore body is stratiform,stratiform-like,lenticular,whith is controled by stratum.The attitude of ore body,the gneissic schistosity of wall stone and the structural lineament are matched.The graphite is filling between the gangue mineral grains.Ores are of lepidoblastic texture and gneissic,massive,banded structure,whith formed from typical regional metamorphism.The graphite ore can be divided into gneiss type and granulite type according to their host rocks.Finally,the origin of graphite formation is summarized: Al and organic rich sedimentary rocks matter formed by regional metamorphism and local carbon enrichment,then the graphite formation is formed.