| 滇西昌宁-孟连带三叠纪花岗岩地球化学、年代学及其意义 |
| |
| 引用本文： | 聂飞,董国臣,莫宣学,朱弟成,董美玲,王霞.滇西昌宁-孟连带三叠纪花岗岩地球化学、年代学及其意义[J].岩石学报,2012,28(5):1465-1476. |
| |
| 作者姓名： | 聂飞 董国臣 莫宣学 朱弟成 董美玲 王霞 |
| |
| 作者单位： | 1. 中国地质大学,北京,100083
2. 中国地质大学,北京100083;中国地质大学地质过程与矿产资源国家重点实验室,北京100083 |
| |
| 基金项目： | 本文受国家重点基础研究发展规划项目(2009CB421002、2011CB403102)、111计划项目(B07011)、长江学者和创新团队发展计划(IRT1083)、深部探测技术与实验研究专项课题(Sinoprobe-04-02)、国土资源部公益性行业科研专项(201011054)和中国地质调查局研究项目(1212011220920)联合资助. |
| |
| 摘 要： | 癞痢头山、云岭和耿马岩体位于昌宁-孟连带的中北段,主要岩性为二长花岗岩,锆石LA-ICP-MS U-Pb定年结果表明,这三个岩体几乎同期侵位于约231Ma。这三个岩体的SiO2含量为65.65%～67.68%,富钾(K2O/Na2O=2.71%～1.42%)和较低钙CaO(1.35%～2.98%),铝饱和指数(A/CNK)为1.10～1.22,富集Rb、Ba、Th、U、K、La和LREE等元素,相对亏损Nb、Ta、Ti、Zr及Hf等高场强元素。这些特征表明3个岩体属于强过铝质高钾钙碱性S型花岗岩。这三个岩体负且变化范围大的锆石εHf(t)值(-26.8～-8.2)和古老的Hf同位素地壳模式年龄(1.2～2.7Ga),表明它们主要来源于古老地壳物质(如含长石和黑云母且贫粘土的杂砂屑岩)的重熔,并有不同程度的幔源物质加入。它们可能侵位于后碰撞背景,可能指示缅泰马微陆块与思茅地块的主体碰撞在232Ma之前(即晚三叠世之前)已经发生。
|
| 关 键 词： | 昌宁-孟连带 锆石U-Pb年龄和Hf同位素 地球化学 岩石成因 构造意义 |
| 收稿时间： | 2/1/2012 12:00:00 AM |
| 修稿时间： | 2012/4/15 0:00:00 |
Geochemistry, zircon U-Pb chronology of the Triassic granites in the Changning-Menglian suture zone and their implications |
| |
| NIE Fei,DONG GuoChen,MO XuanXue,ZHU DiCheng,DONG MeiLing and WANG Xia.Geochemistry, zircon U-Pb chronology of the Triassic granites in the Changning-Menglian suture zone and their implications[J].Acta Petrologica Sinica,2012,28(5):1465-1476. |
| |
| Authors: | NIE Fei DONG GuoChen MO XuanXue ZHU DiCheng DONG MeiLing and WANG Xia |
| |
| Institution: | China University of Geosciences, Beijing 100083, China;China University of Geosciences, Beijing 100083, China;China University of Geosciences, Beijing 100083, China;State Key Laboratory of Geological Processes and Mineral Resources, China University of Geosciences, Beijing 100083, China;China University of Geosciences, Beijing 100083, China;State Key Laboratory of Geological Processes and Mineral Resources, China University of Geosciences, Beijing 100083, China;China University of Geosciences, Beijing 100083, China;China University of Geosciences, Beijing 100083, China |
| |
| Abstract: | Located in the middle and north sections of Changning-Menglian suture zone,Lailitoushan,Yunling and Gengma plutons are mainly composed of monzogranites.The zircon LA-ICP-MS U-Pb dating indicates that the three granitoid plutons intruded simultaneously at about 231Ma.The three plutons have 65.65% ～ 67.68% SiO2,with high K2O(K2O/Na2O = 2.71% ～ 1.42%) and low CaO(1.35% ～ 2.98%).These granitoids are high in A/CNK(1.10 ～ 1.22),and are enriched in Rb,Ba,Th,U,K,La and LREE,but depleted in Nb,Ta,Ti,Zr and Hf.These geochemical signatures indicate that the three plutons are high-K calcalkaline peraluminous S-type granites.The wide and negative zircon εHf(t) values(-26.8 ～-8.2) and ancient Hf-isotope crust model ages(1.2 ～ 2.7Ga) indicate that these three plutons originated mainly from anatexis of ancient crust materials(such as feldspar-and biotite-bearing lithic greywacke) with varying contributions of mantle-derived materials.These plutons probably formed in a post-collisional setting,which may imply that the Burma-Thai-Malaysia microcontinent collided with the Simao block before 232Ma(prior to Late Triassic). |
| |
| Keywords: | Changning-Menglian suture zone Zircon U-Pb ages and Hf isotopes Geochemistry Petrogenesis Tectonic significance |
| 本文献已被 CNKI 万方数据 等数据库收录！ |
| 点击此处可从《岩石学报》浏览原始摘要信息 |
| 点击此处可从《岩石学报》下载免费的PDF全文 |
|
