Discussion on zircon LA-ICP-MS ages of Lianshanguan-Gaojiagou granites and its significance

Through method of LA-ICP-MS to single zircon,the authors obtained an accurate 2198±31.5 Ma and 2162±31 Ma ages of Lianshanguan-Gaojiagou granite which located in the eastern of Liaoning province, China. These two isotopic ages suggest a comprehensive crustal melting-tectonic event occurred in Eastern Liaoning and Southern Jilin area, which can be proved by other single zircon U-Pb ages and regional geology evidence. Furthermore, these ages indicate the precise and reliable time of such re-melt event which benefit to uranium pre-enrichment and strengthened by local evidence from petrology geochemistry and contact relation of field outcrop rocks. Lianshanguan-Gaojiagou complex is a re-melt and multi-intrusion granite occurred under crust extension in paleo-proterozoic era. (authors)