Division of Lithological Units and Geological Evolution of Early Precambrian Basement in Dahuanggou Banshigou Region, South Jilin Province
吉林省大荒沟—板石沟早前寒武纪基底的岩石单元划分及其地质演化

The Early Precambrian basement in Dahuanggou banshigou region of South Jilin Province comprises main four lithological units,i.e. metasupracrustal rocks,coarse biotite felsic gneisses, potassium granites and metabasic rocks. An attempt has been made to elucidate the petrography, geochemistry, metamorphism, geochronology and the relation of these rocks in the paper.Based on the results obtained from the research,we present an outline of the evolution of South Jilin Archean terrain.In the Middle Archean supracrustal rocks were formed. Then amphibolite facies metamorphism happened at 2 6Ga,accompainied by ductile shear deformation.Later plutonic TTG intruded.In Late Archean this region underwent epidote amphibolite metamorphism around 2 53Ga,and later there occurred an event of NE directed ductile shear deformation.In Early Proterozoic, potassium granite intruded and then underwent greenschist facies metamorphism at about 2 3Ga. Two events of NW and NE shear deformation also occurred at the later stage of the final regional metamorphism.