The final closing time of the west Lamulun River-Changchun-Yanji plate suture zone Evidence from the Dayushan granitic pluton, Jilin Province
SUN De-you~(1,2), WU Fu-yuan~(2,3), ZHANG Yan-bin~(3),GAO Shan~(1) est University, Xi'an 710069,China;2.College of Earth Sciences,Jilin University,Changchun130061,China;3.Institute of Geology and Geophysics, Chinese Academy of Sciences, Beijing100029, China)
The zircon UPb isotopic dating shows that the Dayushan pluton, which is located in West Lamulun River-Changchun-Yanji plate suture zone, was formed at the end of the late Permian, not the Caledonian orogeny as originally suggested.The petrological study and studies in element and isotopic geochemistry indicate that the pluton belongs to high-potassium calc-alkaline I-type granite, whose magma came from basic basalt in the thicken crust bottom by partial melting, and are of syn-collisional features. The pluton provides a direct petrological evidence of the plate collision and amalgalation. Combined with the research result on the Hulan Group metamorphism in the region, this paper concludes that the West Lamulun River-Changchun-Yanji plate suture zone in the Eastern Xingmeng orogen closed at the end of Permian.