THE LATE ARCHEAN GEOLOGICAL EVENTS SERIES OF THEHENGSHAN METAMORPHIC TERRAIN AND ITS SIGNIFICANCEFOR CRUSTAL EVOLUTION

Detailed structural-lithologic mapping in typical sectors of the Hengshan metamorphicterrain indicates that there exist basement compleses of the Archean Wutai Group in the ter-rain. During the Late Archean to Early Proterozoic the terrain undrwent the event of formationof supracrustal sequences and emplacement of plutons and polyphase structural deformauon（folding and shearing） and metamorphism. Among other things, large- scale subhorizontalshearing resulted in superimposition of different structural units and anatexis of basement com-plexes. Geological events series recorded accretion, differentiation and finally cratonization ofthe continental crust and subsequent continental rifiting in the Early Precambrian in the Heng-shan area.