| 大兴安岭南端红山子盆地流纹岩的成因:元素和Sr-Nd-Pb同位素制约 |
| |
| 引用本文： | 巫建华,解开瑞,祝洪涛,吴仁贵,刘帅.大兴安岭南端红山子盆地流纹岩的成因:元素和Sr-Nd-Pb同位素制约[J].吉林大学学报(地球科学版),2016(6):1724-1739. |
| |
| 作者姓名： | 巫建华 解开瑞 祝洪涛 吴仁贵 刘帅 |
| |
| 作者单位： | 1. 核资源与环境国家重点实验室培育基地 东华理工大学,南昌,330013;2. 东华理工大学地球科学学院,南昌,330013;3. 核工业 243 地质大队,内蒙古 赤峰,024006 |
| |
| 基金项目： | 国家自然科学基金项目(41372071)，中国核工业集团公司项目(中核地计200874)Supported by Project of National Natural Science Foundation of China(41372071)，Project of CNNC(200874) |
| |
| 摘 要： | 红山子晚侏罗世早期火山盆地位于西拉木伦河—长春缝合带以南、康宝—围场—赤峰—开原断裂带以北的辽源地块,其中赋存铀钼矿床的流纹岩为肉红色流纹岩和灰白色流纹岩。为了查明流纹岩的物质来源和形成的构造背景,本文分析了流纹岩的主量元素、微量元素、稀土元素和Sr-Nd-Pb同位素组成。分析结果显示:流纹岩具有高SiO_2、K_2O和Fe_2O_3/FeO值,低Al_2O_3、CaO和MgO的特征,肉红色流纹岩比灰白色流纹岩的SiO_2含量略低、(K_2O+Na_2O)含量高和Fe_2O_3/FeO值略高;肉红色流纹岩和灰白色流纹岩均有较高的稀土含量,明显富集轻稀土,显著亏损铕;高场强元素Nb、Ta、Zr、Hf、Ce、Y、Ga和大离子亲石元素Rb、Th、U的含量较高,但大离子亲石元素Ba、Sr的含量低且变化较大,具有A1型流纹岩、低Sr-Ba流纹岩和板内拉张构造流纹岩的微量元素特征;具有较小的(87Sr/86Sr)i、较高的εNd(t)、较年轻的TDM 2和较低的(206Pb/204Pb)i、(~(207)Pb/~(204)Pb)i、(~(208)Pb/~(204)Pb)i,指示流纹岩是源于EMⅠ富集地幔的中元古代年轻下地壳部分熔融的产物,并在岩浆过程中经历了结晶分异。肉红色流纹岩和灰白色流纹岩的差异可能与年轻下地壳物质的成分差异有关。
|
| 关 键 词： | 流纹岩 Sr-Nd-Pb同位素 晚侏罗世早期 红山子盆地 大兴安岭南端 |
Petrogenesis of Rhyolite from Hongshanzi Basin in Southern Greater Xing’an Range:Elements and Sr Nd Pb Isotope Constraints |
| |
| Wu Jianhua,Xie Kairui,Zhu Hongtao,Wu Rengui,Liu Shuai.Petrogenesis of Rhyolite from Hongshanzi Basin in Southern Greater Xing’an Range:Elements and Sr Nd Pb Isotope Constraints[J].Journal of Jilin Unviersity:Earth Science Edition,2016(6):1724-1739. |
| |
| Authors: | Wu Jianhua Xie Kairui Zhu Hongtao Wu Rengui Liu Shuai |
| |
| Abstract: | The Hongshanzi early Late Jurassic volcanic basin is located in Keshenketeng Banner,Inner Mongolia,the southern tip of the Greater Xing’an Range.Its tectonic position is within the Liaoyuan block between the Xilamulun-Changchun suture zone and the Kangbao-Weichang-Chifeng- Kaiyuan fault belt.The fresh red and grey rhyolites,in Hongshanzi basin,are the wall rocks of hydrothermal-type U Mo deposits.Both have the features of rich in SiO2 ,K2 O and high ratio of Fe2 O3/FeO,with lack of Al2 O3 ,CaO and MgO contents,the fresh red rhyolite is higher in(K2 O+ Na2 O)contents and Fe2 O3/FeO ratio,while lower in SiO2 .Both fresh red and grey rhyolites,are relatively high the total amount of REE,showing rich LREE obviously and right REE patterns,with negative Eu anomalies.The high contents of HSFE(Nb,Ta,Zr,Hf,Ce,Y,Ga)and LIRE(Rb,Th, U),low contents of the LIRE Ba and Sr,show the trace elements feature of A1 type rhyolite,low Ba Sr type rhyolite and the extensional tectonic setting.The rhyolites have smaller (87 Sr/86 Sr)i ,higher εNd (t ),younger T DM 2 ,lower (206 Pb/204 Pb)i ,(207 Pb/204 Pb)i ,(208 Pb/204 Pb)i .Obviously,both fresh red and grey rhyolites were formed by the partial melting of Mid-Mesoproterozoic young lower crust materials originated from the EMⅠenriched mantle under the extensional tectonic setting within the plates,and had been accompanied by the fractional crystallization during the magmatic process.Their differences may be related to the different composition of young lower crustal materials. |
| |
| Keywords: | rhyolite Sr Nd Pb isotopes early Late Jurassic Hongshanzi basin the southern tip of Greater Xing’an Range |
| 本文献已被 CNKI 万方数据 等数据库收录！ |
|
