The Sunjiahe Formation of the Xixiang Group, southern Qinling Ranges: SHRIMP zircon U-Pb age and its tectonic implications

The dacitic lavas from the Sunjiahe Formation in the Xixiang Group, southern Qinling Ranges are examined on the basis of lithochemical, REE and Trace element data, and give a SHRIMP zircon U-Pb age of 814.8±5.2 Ma which represents the late Qingbaikouan. This age provides a new evidence for the approaches to the ages of the transitional besement of the Yangtze block in southern Qinling Ranges, and the convergence timing of the supercontinent Rodinia in the Yangtze block and tectonic evolution of the Qinling orogenic zone.