PETROLOGY AND GEOCHRONOLOGY OF THE PALEO-JILIN-HEILONGJIANG OROGENIC BELT IN THE ADJECENT AREAS OF CHINA,RUSSIA AND KOREA

According to the recent petrologic and geochronologic records,the basement of the paleo-Jilin-Heilongjiang orogenic belt in the adjecent areas of China,Russia and Korea is composed of the Rodinia supercontinent that was formed by the joint pcocesses of tectonics,magmatism,metamorphism and mineralization at ca.1000 Ma.The Assyntian-Xingkai orogeny,as an important developing period of the paleo-Asian Ocean,represents the active response of the region to the splitting of Rodinia supercontinent (from ca.900 Ma)until the matching of Gondwana-Laurentia supercontinent (during 545to 525 Ma).The tectonic cycles of Caledonia(440-445 Ma),Late Varascan(ca.350 Ma)and Early Indosinia(250-230 Ma)completed the transformation from paleo-Asian Ocean to paleo-Tethys,and formed the paleo-Eurasian continent,which responded to the convergence of the Pangea.Especially in Early Indosinia cycle,a completive petrologic and chronolo gicrecord on the continuous process of "continent-continent convergence-intracontinental underthrust-orogenic belt collapse" was formed.