SHRIMP U-Pb dating for zircons from pyroxene andesite of Shuiquangou Formation in western Liaoning province and its tectonic significance.
The Shuiquangou Formation, located in the Lingyuan area of western Liaoning, lays unconformably over the first thrust system formed during the Early Mesozoic and is covered by a early Yanshanian thrust. The SHRIMP age of zircons from pyroxene andesite of Shuiquangou Formation is 230.4 Ma±3.1 Ma. The result shows that the age of Shuiquangou Formation is the Late Triassic; the lithosphere in western Liaoning is in a stretching setting during the Late Triassic and the thrusting of the early Early Mesozoic in Yanshan mountains was occurred in the Early and Middle Triassic. It suggests that the early stage of Indochina movement is thrusting and the late is extension.