| 哀牢山构造带两侧上志留统-下泥盆统碎屑锆石年代学:物源及其构造意义 |
| |
| 引用本文： | 刘兵兵,彭头平,范蔚茗,高剑峰,方小玉,张靖祎.哀牢山构造带两侧上志留统-下泥盆统碎屑锆石年代学:物源及其构造意义[J].大地构造与成矿学,2017,41(4):734-752. |
| |
| 作者姓名： | 刘兵兵 彭头平 范蔚茗 高剑峰 方小玉 张靖祎 |
| |
| 作者单位： | 1. 中国科学院广州地球化学研究所同位素地球化学国家重点实验室,广东广州 510640;中国科学院大学,北京 100049;2. 中国科学院广州地球化学研究所同位素地球化学国家重点实验室,广东广州 510640;中国科学院青藏高原地球科学卓越创新中心,北京 100101;3. 中国科学院青藏高原地球科学卓越创新中心,北京 100101;中国科学院青藏高原研究所,北京 100101;4. 中国科学院地球化学研究所矿床地球化学国家重点实验室,贵州贵阳,550081 |
| |
| 基金项目： | 国家973 项目，国家基金面上项目，百人计划项目 |
| |
| 摘 要： | 哀牢山古特提斯洋的打开时限及其缝合带的具体位置对理解哀牢山古特提斯洋构造演化具有非常重要的意义。本文采用碎屑锆石年代学方法,分析了哀牢山构造带及其两侧不同时期沉积物源的特征及其变化,解译了其物源差别所指示的哀牢山古特提斯洋盆打开时限以及缝合带的构造位置。碎屑锆石年代学显示,哀牢山构造带两侧上志留统碎屑锆石都记录一个~450 Ma的最年轻的峰值和一个格林威尔期造山事件的年龄群(1100~800 Ma),以及一个2600~2400 Ma的次峰;不同于上志留统,构造带东侧下泥盆统碎屑锆石并未出现年轻的~450 Ma峰值年龄信息,西侧U-Pb年龄分布模式与上志留统一致,记录~450 Ma峰值年龄信息,而且构造带两侧下泥盆统碎屑锆石的2600~2400 Ma的峰值明显要强于上志留统。区域上发表的碎屑锆石年代学资料,也揭示相同的年龄峰值。因此,综合区域上的其他地质资料,我们认为哀牢山古特提斯洋盆的打开时限应该在晚志留世-早泥盆世,哀牢山断裂带代表了哀牢山洋盆闭合的位置。
|
| 关 键 词： | 年代学 碎屑锆石 晚志留世?早泥盆世 哀牢山构造带 古特提斯洋 |
Geochronology of Detrital Zircon from the Upper Silurian-Lower Devonian Sedimentary Rocks at both Sides of the Ailaoshan Tectonic Zone: Provenance and Geological Significance |
| |
| LIU Bingbing,PENG Touping,FAN Weiming,GAO Jianfeng,FANG Xiaoyu,ZHANG Jingyi.Geochronology of Detrital Zircon from the Upper Silurian-Lower Devonian Sedimentary Rocks at both Sides of the Ailaoshan Tectonic Zone: Provenance and Geological Significance[J].Geotectonica et Metallogenia,2017,41(4):734-752. |
| |
| Authors: | LIU Bingbing PENG Touping FAN Weiming GAO Jianfeng FANG Xiaoyu ZHANG Jingyi |
| |
| Abstract: | Constrainingthe precise time of opening and location of the suture of the Ailaoshan Paleotethys is crucial to better understand the tectonic evolution of the whole Paleotethys in Southwest China. In this contribution, we carried out a systematic U-Pb analysis of detrital zircon to provide insights into the provenance of sedimentary materials, temporal variation, and their geological significance. The dating results of detrital zircon grains from the Upper Silurian?LowerDevonian sedimentary sandstones from both sides of the Ailaoshan tectonic zone show that all the Upper Silurian detrital zircon grains are characterized by a similar youngest age peak at ca. 450 Ma and two subordinate age populations including the Greenville orogenic events (1100?800 Ma) and the 2600?2400 Ma age group. Detrital zircon grains in the Lower Devonian rocks gave similar age populations with an exception of those from the east side of the Ailaoshan tectonic zone lack the youngest age peak at ca. 450 Ma. In addition, the detrital zircon grains in the Lower Devonian rocks display age peak at 2600?2400 Ma more significant than the Upper Silurian ones. By comparison with the published dating data of detrital zircon, a common characteristic with same age populations has also been revealed. Integration with the regional geological data, we propose that the opening of the Ailaoshan Paleotethys Ocean took place during the Late Silurian to Early Devonian and the Ailaoshan Fault should represent the location of the Paleotethys suture zone. |
| |
| Keywords: | geochronology detrital zircon the Late Silurian?Early Devonian Ailaoshan tectonic zone Paleotethys |
| 本文献已被 CNKI 万方数据 等数据库收录！ |
|
