连山关-高家沟花岗岩体LA—ICP—MS锆石U—Pb年龄及其地质意义

笔者采用颗粒锆石LA—ICP—MS法获得了连山关-高家沟花岗岩体U—Pb不一致线上交点年龄为2198±31．5Ma和2162±31Ma。通过与辽东地区U—Pb法、Sm—Nd法和颗粒锆石年龄比对，揭示了辽东地区广泛发育的一期古元古代花岗岩浆事件的精确年代。根据岩石地球化学特征和岩体与地层接触关系，笔者认为该期花岗岩是在拉伸状态下早期基底岩石重熔的产物。年代学资料表明，连山关-高家沟岩体为壳源岩浆多次重熔侵位的花岗杂岩体。

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.