U-Pb Zircon Geochronology of the Zijinshan Alkaline Intrusive Complex, Shanxi Province, and Its Geological Significance by Using LA-ICP-MS
摘要
The Zijinshan alkaline intrusive complex,located in the eastern margin of the Ordos Basin, mainly consists of salite monzonite, diopside syenite, and nepheline-diopside syenite.This paper presented the zircon LA-ICP-MS data of U-Pb in salite monzonite and salite syenite from the Zijinshan alkaline complex. Zircon rims from salite monzonite sample are magmatic genesis with oscillatory and sector zoning,and have Th/U ratios of 0.781 to 2.559, with 206Pb/238U age of (136.7±6.5) Ma. In addition,the other two zircon grains from monzonite yield 206Pb/238U apparent ages of (222±4) Ma and (323±3) Ma, respectively, probably representing the timing of the magma underplating.