云南马厂箐钾质碱性花岗岩特征和锆石U-Pb年龄

Geochemical Characteristics and Zircon SHRIMP U-Pb Age of the Machangqing Kaligranite in Yunnan Province

马厂箐钾质碱性花岗岩岩石化学成分中具富碱高钾和富钙特征,微量元素富集Sr、Ba等大离子亲石元素,亏损Nb、Ta等高场强元素。在稀土元素组成上,富集轻稀土(LREE/HREE=22.2～25.0),基本无铕异常(δEu=0.80～1.10)。锆石SHRIMPU-Pb年龄为(34±0.5)Ma,相当于晚始新世,属喜马拉雅期。

The petrochemistry of the Machangqing kaligranite is characterized by rich alkali,high potassium and calcium.The kaligranite is enriched in large lithophile elements such as Sr and Ba and depleted in high strength field elements like Nb and Ta.The rocks are relatively enriched in LREE（LREE/HREEE）=22.2～25.0,showing on obvious Eu anomalies（δEu=0.80～1.10）.The granite was formed in Late Eocene with zircon SHRIMP U-Pb age of（34±0.5）Ma.