| Chlorites are widely distributed in altered rocks of many deposits,and are important symbols of genesis of gold deposits and porphyry Cu Mo deposits,which are always valued.However,chlorites of BIF type high-grade iron ore deposits which are closely related to mine have not been studied enough.So,this paper was based on the regional geological background and geological features of the rich iron ore deposit,the characteristics of rock,mineralogy,geochemistry of chlorite rocks and mineralogy and typomorphic characteristics of chlorite were studied,acquiring the following conclusions:1.Stratum of BIF rich iron ore deposits of Gongchangling belongs to Archean Anshan group Cigou group,located in the northern wing of the Gongchangling anticline.Iron rich ore generally in shape of stratoid,lumpy,veined,exists in banded magnetite quartzite.The phenomenon of the rich ore body controlled in fault structures of the rich iron ore deposits is obvious.Rich iron ores are mainly made up of magnet ore and hematite ore.2.The altered rocks are widely distributed in the rich iron ore deposit,distributed at one side or both sides of the rich iron ore body,the wall rocks alteration has obvious zoning,and the two were positively related to the scale.Alteration types are mainly chloritization,Cummingtonite mineralization and Iron and aluminium garnet mineralization.According to the relationship between the output space position of chlorite rocks and orebody,chlorite rocks are divided into chlorite rocks of rich iron ore body roof,chlorite rocks near orebody rock and chlorite rocks existing in magnetite quartzite and a little far orebody surrounding rock.The symbiotic mineral of chlorite is garnet mafic amphibole,biotite,quartz,magnetite etc.3.Geochemical test results show that chlorite rocks contains more iron,magnesium,aluminum and silicon;The content of iron containing silicon and the amount of silicon show a significant negative correlation.Trace and REE characteristics show that chlorite rocks were formed in reducing environment,not the result of marine chemical deposition,Material sources were closely related to the volcanic action.Through the recovery of the raw rock of the chlorite rocks,the original rock of the chlorite rocks is thick mudstone.4.Chlorite in rich iron ore deposit is mainly ripidolite,followed by pycnochlorite.According to X ray analysis,it can be known that the types of symbiotic mineral of chlorite are the same with the observation results of the rock specimen and the mirror.According to the lattice parameters of chlorite and iron containing coefficient,the relationship of a0?b0 and the coefficient of iron containing iron is positively related,c0 contrary.According to the results of differential thermal analysis,to the chlorite containing more Fe,with the increase of Fe/Mg+Fe,the lower the temperature of the endothermic peak,the temperature of the exothermic peak also decreased,but the heat release peak is not more and more obvious.By studying the causes of chlorite of rich iron ore deposit in Gongchangling,the chlorite is the cause of the formation of sedimentary regional metamorphism. |
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