鲁西峄山岩体的形成时代——锆石SHRIMP UPb定年的证据

Forming Age of Yishan Rock in Luxi Area——Evidences of SHRIMP Zircon Dating

摘要:

峄山岩体主要岩性为片麻状花岗闪长岩及斑状片麻状花岗闪长岩，根据新测的锆石SHRIMP UPb年龄结果，片麻状花岗闪长岩为（2526±10）Ma，斑状片麻状花岗闪长岩为（2514±18）Ma，其形成时代确定为新太古代晚期。该岩套出露于鲁西新太古代早期泰山岩群和英云闪长质片麻岩、条带状英云闪长质片麻岩组成的古陆核的西南部，是地幔岩浆侵入混入地壳物质形成的。

Abstract:

Major properties of Yishan rock are gneissic granodiorite and porphyritic gneissic granodioritemonzonite. According to new measurements of zircon SHRIMP UPb dating result, the age of gneissic granodiorite monzonite is 2525Ma, porphyritic gneissic granodiorite is 2522± Ma and (2514±18) Ma. Its formation age is determined to be late Archean. This rock series exposed in the southwest of ancient continental nucleus composed by early period of Taishan group in Neoarchean in Luxi area, tonalite gneiss and banded tonalitic gneiss. It is formed by mantle magma intrusion mixed with crustal materials.