| 鲁西济南辉长岩的形成时代:锆石LA-ICP-MS U-Pb定年证据 |
| 点此下载全文 |
| 引用本文：杨承海,许文良,杨德彬,刘长春,柳小明,胡兆初.2005.鲁西济南辉长岩的形成时代:锆石LA-ICP-MS U-Pb定年证据[J].地球学报,26(4):321-325. |
| DOI：10.3975/cagsb.2005.04.05 |
| 摘要点击次数: 3085 |
| 全文下载次数: 3324 |
| 作者 | 单位 | E-mail | | 杨承海 | 吉林大学地球科学学院,吉林长春,130061
山东省地质矿产局,山东济南,250013 | xuw126@sina.com | | 许文良 | 吉林大学地球科学学院,吉林长春,130061 | | | 杨德彬 | 吉林大学地球科学学院,吉林长春,130061 | | | 刘长春 | 山东省地质矿产局,山东济南,250013 | | | 柳小明 | 西北大学大陆动力学重点实验室,陕西西安,710069 | | | 胡兆初 | 西北大学大陆动力学重点实验室,陕西西安,710069 | |
|
| 基金项目:国家自然科学基金重点项目（编号：40133020和40472033）;西北大学大陆动力学重点实验室开放实验室基金项目资助 |
|
| 中文摘要:采自济南药山、鹊山、华山和匡山辉长岩中锆石的阴极发光图像显示出自形-半自形的晶形和均匀条带状吸收的特征,锆石的Th/U比值介于0.44～1.46之间,表明它们具有岩浆成因特征.本文对药山、鹊山和华山辉长岩中30粒锆石以及匡山辉长岩中11粒锆石进行了LA-ICP-MSU-Pb年龄测定,结果表明30个测定点的206Pb/238U年龄主要集中在124～142Ma之间,其加权平均值为130.8±1.5Ma,11个测定点的206Pb/238U加权平均值为127±2Ma,表明岩体的侵位结晶年龄为早白垩世.华北克拉通东部早白垩世济南辉长岩和同时代花岗质岩石的存在代表了双峰式岩浆作用的特征,进而反映了强烈伸展环境的地球动力学背景. |
| 中文关键词:辉长岩 锆石 LA-ICP-MS U-Pb定年 中生代 济南 |
| |
| Chronology of the Jinan Gabbro in Western Shandong: Evidence from LA-ICP-MS Zircon U-Pb Dating |
|
|
| Abstract:The zircons from Jinan gabbro show euhedral-subhedral shapes and striped absorption on their cathodoluminescence (CL) images. The Th/U ratios of zircons range from 0.44 to 1.46, indicating that they were formed by normal crystallization of magma. U-Pb dating of 30 zircons from Queshan, Huashan, and Yaoshan gabbros and of 11 zircons from Kuangshan gabbro was made on LA-ICP-MS. The results show that the data of 30 zircons cluster around the concordia of 124～142 Ma, yielding a weighted mean (206Pb)/238U age of 130.8±1.5 Ma, and that the data of 11 zircons yield a weighted mean ()206Pb/238U age of 127±2 Ma, which implies that the crystallization of the Jinan gabbro occurred in Early Cretaceous. It is held that the coexsitence of Early Cretaceous Jinan gabbro and synchronous granitoid characterizes bimodal magmatism in eastern North China craton and also implies the geodynamic background of a strong extension environment. |
| keywords:gabbro zircon LA-ICP-MS U-Pb dating Mesozoic Jinan |
| 查看全文 查看/发表评论 下载PDF阅读器 |
|
|
|
|
|
