Abstract:Geochemical data indicate that Yajiangqiao trondhjemite, Huatan trondhjemite and Mopanshan granite, considered as component parts of Kangding complex formed in Late Archean or Palaeoproterozoic, are similar to TTG in such aspects as low Mg#, Na2O＞K2O, strong fractionationed REE, no or slightly negative Eu anomaly, low YbN, Cr, Ni, V, Nb, Ta, Ti, high Ba, and changeable Sr. SHRIMP zircon dating suggests that Yajiangqiao trondhjemite was emplaced in 778±11 Ma. The results of the study show that Kangding complex is composed of Neoproterozoic granites bearing characteristics of TTG. The formation environments of TTG together with the results of previous studies imply that Neoproterozoic granites were formed by melted basaltic ocean crust under the condition of plate subduction along the western margin of Yangtze block.
