THE Sm-Nd AGE OF AMPHIBOLITES IN THE XIAHE GROUP COMPLEX IN NORTH QINLING

Amphibolite（whose protolith is basic volcanics ）from the Xiahe Group Complex in the Pailougou area on the Henan-Shanxi border in the eastern sector of the North Qinling orogenic belt has been determined to have a whole-rock Sm-Nd isochron age of 1605±76Ma with εNd（T）= + 5. 3. This indicates that the metamorphic series of the Xiahe Group Complex was formed in the Middle Proterozoic and that the amphibolite was derived from the depleted mantle.The aforesaid data provide evidence for discussing the Middle Proterozoic tectonic evolution in the North Qinling orogenic belt.