Zircon U——Pb ages and Hf isotopic composition of volcanic rocks from Well Linshen 3 in Songliao Basin

The formation time and the source rocks of volcanic rocks from Well Linshen 3 in the northern Songliao Basin have been discussed through the petrography,major and trace elements,zircon U——Pb isotopic data and zircon Hf isotopic data of three samples.Zircon U——Pb dating by LA——ICP MS technique indicated that the volcanic rocks from Well Linshen 3 were erupted at ca.120 Ma,the middle——late Early Cretaceous,belonging to of the Yingcheng Formation.Zircon Hf analysis conducted by LA——MC——ICPMS showed that all of the volcanic rocks had high eHf(t)positive values with Hf modal ages of 789~1 494 Ma,indicating the crust in the Songliao Basin extracted from mantle during Meso-and Neoproterozoic,which provides the important evidence of crustal growth during Meso-and Neoproterozoic in eastern Xing——Meng orogenic belt.