Petrogenesis of Volcanic Rocks from Xixiang Group in Middle Part of South Qinling Mountains

The volcanic orcks form Xixiang Group(nicluding Sunjaihe Formation,Dashigou Formation,and Baimianxia Formation)situated in the middle part of South Qinlnig Mountains were formed during the mid-Neoproteorzoic(730-827Ma)and in an intracontniental rift setting.They are most likely related to the proposed mantle plume that led to the rifting-breakup of the Rodinia supercontinent.