| 大兴安岭北部新林石英二长岩-花岗岩的地球化学特征及其成因 |
| |
| 引用本文： | 孙如江,孙德有,苟军,王广婷,杨东光,李旭.大兴安岭北部新林石英二长岩-花岗岩的地球化学特征及其成因[J].世界地质,2016,35(2):309-323. |
| |
| 作者姓名： | 孙如江 孙德有 苟军 王广婷 杨东光 李旭 |
| |
| 作者单位： | 吉林大学 地球科学学院，长春 130061 |
| |
| 摘 要： | 对额尔古纳地块东南部新林镇附近的侵入岩进行了锆石U-Pb年龄测定、Lu-Hf同位素和岩石地球化学研究。结果表明,岩体形成于141.1~123.8 Ma,是早白垩世岩浆活动的产物。新林石英二长岩-花岗岩高硅较富铝贫镁,属于准铝质、高钾钙碱性系列;具有中等-弱负Eu异常(δEu=0.53~0.72),轻重稀土分异比较明显(La/Yb)_N=12.42~25.38];相对富集大离子亲石元素Rb、Th、U和LREE,高场强元素Ti、Nb、Ta、P和HREE表现出亏损。新林石英二长岩-花岗岩具有高Sr、低Yb及低Y的特征,且相对富K,属于C型埃达克岩,形成于加厚下地壳的部分熔融。Lu-Hf同位素研究显示其ε_(Hf)(t)为2.1~6.2,二阶段模式年龄(T_(DM2))为1025~786 Ma,认为其岩浆源区为新元古代增生的地壳物质。
|
| 关 键 词： | 新林 埃达克 锆石年龄 地球化学 岩石成因 大兴安岭北部 |
Geochemical characteristics and petrogenesis of adamellite- granite in Xinlin Town，northern Da Hinggan Mountains |
| |
| SUN Ru-Jiang,SUN De-You,GOU Jun,WANG Guang-Ting,YANG Dong-Guang,LI Xu.Geochemical characteristics and petrogenesis of adamellite- granite in Xinlin Town，northern Da Hinggan Mountains[J].World Geology,2016,35(2):309-323. |
| |
| Authors: | SUN Ru-Jiang SUN De-You GOU Jun WANG Guang-Ting YANG Dong-Guang LI Xu |
| |
| Institution: | College of Earth Sciences，Jilin University，Changchun 130061，China |
| |
| Abstract: | The authors studied the zircon U-Pb dating and geochemical characteristics of Lu- Hf isotope，ma- jor，trace and ＲEE elements of intrusive adamellite- granite near Xinlin Town，southeastern Erguna terrane block． The results show the adamellite- granite were formed in Early Cretaceous，ranged from 141. 1 Ma to 123. 8 Ma in age． The study suggests that adamellite- granite is rich in silicon，alkalis，poor in magnesium，which all belong to quasi- aluminous and high- kalium calc- alkaline series，and display moderate- weak negative europium anomalies (δEu =0. 53 ～0. 72)，showing significant fractionation of HＲEE and LＲEE ［(La/Yb) N =12. 42 ～25. 38］ ; The adamellite- granite is also characterized by enrichment in Ｒb，Th，U and LＲEE and depletion in Ti，Nb，Ta，P and HＲEE． The adamellite- granite in Xinlin is characterized by enrichment in Sr and K，depletion in Yb and Y， belonging to C- type adakite， origrinated from partial melting of thicken lower crusts． The research on Lu- - Hf isotope shows ε Hf (t) ranging from 2. 1 to 6. 2，T DM2 ranging from 1 025 Ma to 786 Ma，which is considered the adamellite- granite magma origrinated from juvenile crusts during the Neoproterozoic． |
| |
| Keywords: | Xinlin adakite zircon U-Pb dating geochemistry petrogenesis northern Da Hinggan Mountains |
| 本文献已被 CNKI 等数据库收录！ |
| 点击此处可从《世界地质》浏览原始摘要信息 |
| 点击此处可从《世界地质》下载免费的PDF全文 |
|
