XIAHE GROUP COMPLEX IN EAST QINLING AND RELATED PROBLEMS

The Xiahe Group Complex in East Qinling is a Middle Proterozoic stratigraphic unit separated recently from the middle part of the original Qinling Group Complex.It is distributed in a NW direction on the Henan Shaanxi border.In the Jinningian period the protoliths of the Xiahe Group Complex plunged down and were buried at depths,thus forming a metamorphic terrane.In the Caledonian Hercynian,the rocks were uplifted in a ductile state and underwent reworking,on which the granitic thermal dome was superimposed. These processes were accompanied by tectonic emplacement and high pressure metamorphism of eclogite.The determination of this group complex provides new important information for the study of the composition,tectonic framework and evolution of the core complex of the Qinling orogen.