| 中国中部蓝片岩的形成时代 |
| |
| 引用本文： | 李曙光,王松山.中国中部蓝片岩的形成时代[J].地质科学,1993,28(1):21-27. |
| |
| 作者姓名： | 李曙光 王松山 |
| |
| 作者单位： | 1. 中国科学技术大学地球与空间科学系 合肥 230026;2. 中国科学院地质所 北京 100029 |
| |
| 摘 要： | 报道了皖中张八岭群中蓝片岩的40Ar/39Ar年龄为245.1±0.5Ma。该年龄与扬子陆块北缘的其它高压变质岩及高压变质矿物的年龄一致,说明中国中部蓝片岩带与榴辉岩带一样形成于三叠纪。动力学分析表明,Sr同位素在干的高压变质过程中均一化尺度很小(<1m),因此该带含蓝片岩地层的元古代Rb-Sr全岩等时线年龄指示的是它经历的第1次区域变质时代,不是后来发生的高压变质时代。此外,还对榴辉岩K-Ar年龄与Sm-Nd年龄的矛盾问题进行了讨论。
|
| 关 键 词： | 蓝片岩 同位素年代学 高压变质作用 秦岭—大别山造带 |
| 收稿时间： | 1992-05-01 |
| 修稿时间： | 1992-05-01; |
TIME OF THE BLUESCHIS BELT FORMATION IN CENTRAL CHINA |
| |
| Li Shuguang Liu Deliang Chen Yizhi.TIME OF THE BLUESCHIS BELT FORMATION IN CENTRAL CHINA[J].Chinese Journal of Geology,1993,28(1):21-27. |
| |
| Authors: | Li Shuguang Liu Deliang Chen Yizhi |
| |
| Institution: | 1. Department of Earth and Space Sciences, University of Science and Technology of China, Hefei 230026;2. Institute of geology, Academia Sinica, Beijing 100029 |
| |
| Abstract: | A 40Ar/39Ar age of 245.1 ?0.5 Ma for the blueschist developed in Zhangbaling Group of Anhui Province is reported in this paper. This age is consistant with the ages of other high pressure metamorphic rocks and minerals. All of these ages document that the blueschist belt in central China was formed in Triassic. Kinetic analysis shows that the scale length of Sr isotopic homogenization in the period of high pressure metanorphism is less than 1 m. Therefore, the Proterozoic age given by Rb-Sr whole rock isochron for a meta-volcanic formation in which blueschist occurs has reflected the time of the occurcence of the first regional meta-morphism, in this formation rather than the time of the later high pressure metamorphism. In addition, the contradiction between K-Ar ages and Sm-Nd ages for eclogites in this belt is also discussed. |
| |
| Keywords: | Greenschist Isotopic chronology High-pressure metamorphism Qinling-Dabie orogenic belt |
| 本文献已被 CNKI 维普 等数据库收录！ |
| 点击此处可从《地质科学》浏览原始摘要信息 |
| 点击此处可从《地质科学》下载免费的PDF全文 |
