THE RECOGNITION OF ORIGINAL ROCKS OF FELSIC METAMORPHIC ROCKS IN GUANGCHANGLING ARCHEAN BANDED IRON FORMATION AND STRATIGRAPHIC IMPLICATION
弓长岭太古代条带状硅铁建造中长英质变质岩的原岩恢复及地层学意义

This study recognized that original rocks of the felsic metamorphic rocks from a key horizon (termed K and K_S) in Guangchangling Archean Banded Iron Formation are tuffaceous intermediate acidic volcanic lava for biotite-quartz-albite gneiss (K) and tuffaceous sedimentary rock for garnet-mica-quartz schist (K_S) respectively.Therefore, K and K_S can not be the same horizon. According to this and some new stratigraphic sections, the stratigraphic section for Guangchangling Archean Banded Iron Formation was renewed. It suggests that this banded iron formation was developed in a shallow sea environment on a continental shelf and the iron ore beds are in mid-upper part of the transgressive series. The characteristics of sedimentary rock association of Guangchangling Banded Iron Formation are different from that of greenstone belt and similar to that of typical supracrustal rocks in high-grade terranes.