The chemical and carbon isotopic compositions of volatiles in Cenozoic high-potassic basalts in western Qinling, China and their mantle geodynamic implications
文献类型：期刊论文
| 作者 | Tang QingYan1; Zhang MingJie1; Li XiaoYa1; Li LiWu2; He PeiPei1; Lin Yao1 |
| 刊名 | ACTA PETROLOGICA SINICA
 |
| 出版日期 | 2012-04-01 |
| 卷号 | 28期号:4页码:1251-1260 |
| 关键词 | Mantle dynamics Carbon isotope Chemical composition Volatile High-potassic basalts Western Qinling |
| ISSN号 | 1000-0569 |
| 文献子类 | Article |
| 英文摘要 | India-Asia continental plate subduction and collision lead to widespread Cenozoic potassic-ultrapotassic magmatism in the Tibet which provides a valuable indicator of the composition and nature of the deep mantle beneath the Tibet. The Cenozoic mantle xenolith bearing high-potassic basalts (7.1 similar to 23Ma) distributed in western Qinling, western China are a window to probe the mantle composition and geodynamics beneath north-eastern margin of Tibet Plateau. The chemical and carbon isotopic compositions of volatiles in olivine(Olv) and plagioclase (P1) phenocrysts and matrix (Mtx) of Cenozoic high-potassic basalts in western Qinling have been determined by stepwise heating mass spectrometer to reveal volatile sources and geodynamic implications under the system of continental plate subduction and collision. The results showed that the volatiles in high-potassic basalts were released by stage at temperature intervals of 200 similar to 400 degrees C, 400 similar to 800 degrees C and 800 similar to 1200 degrees C, and are characterized by dominant H2O with minor CO2 and SO2 as well as detectable He. The olivine phenocrysts show higher release temperature interval (900 similar to 1200 degrees C) of main volatiles than those in mantle xenoliths in eastern China and ultramafic intrusion (400-800T) in other regions,anti are mainly composed of SO2 (68. 72mm(3)/g) and CO2 (59. 46 mm(3)/g) etc. oxidized volatiles. The contents of H2O and CO2 increased gradually from olivine phenocrysts to plagioclase phenocryst and matrix. Olivine phenocrysts display relatively lighter delta C-13(CO2) (26. 21%0 similar to -20. 85 parts per thousand, av. -23.32 parts per thousand) and delta C-13(CH4) (-42. 35 parts per thousand similar to-38. 17 parts per thousand, av. -40. 03 parts per thousand) than matrix(-16. 43 parts per thousand similar to -11. 67 parts per thousand, av. -13. 22 parts per thousand for CO2, -44. 22 parts per thousand similar to -34. 03 parts per thousand, av. -39. 70 parts per thousand for CH4), which show the delta C-13 features of crust with thermal cracking component of organic matters. The volatiles in primary magma are mainly composed of SO2, N-2 and CO2, and could be derived from a deep mixes mantle reservoir and developed in high f(circle 2) environment. They could be mixed by coexisting carbonatite magma or assimilated by the local Carboniferous carbonate which magma penetrated, and had been added by a large quantity of H2O and CO2 during magma ascent and evolution. The chemical and carbon isotopic compositions of volatiles suggested that a recycled crustal component derived from the devolatilization of subducted oceanic plate or sedimentary rocks, which could be related to paleo-Tethyan oceanic plate or Northern China plate with Yangtze plate subduction and collision under the system of India-Asia collision. |
| WOS关键词 | BENEATH SOUTHERN TIBET ; GANSU PROVINCE ; EASTERN CHINA ; ULTRAPOTASSIC MAGMATISM ; KAMAFUGITE ; XENOLITHS ; ROCKS ; METASOMATISM ; GEOCHEMISTRY ; PETROGENESIS |
| WOS研究方向 | Geology |
| 语种 | 英语 |
| WOS记录号 | WOS:000303970100021 |
| 出版者 | SCIENCE PRESS |
| 源URL | [http://ir.iggcas.ac.cn/handle/132A11/84628]  |
| 专题 | 中国科学院地质与地球物理研究所 |
| 通讯作者 | Tang QingYan |
| 作者单位 | 1.Lanzhou Univ, Sch Earth Sci, MOE, Key Lab Western Chinas Environm Syst, Lanzhou 730000, Peoples R China 2.CAS, Inst Geol & Geophys, Key Lab Petr Resource Res, Lanzhou 730000, Peoples R China |
| 推荐引用方式 GB/T 7714 | Tang QingYan,Zhang MingJie,Li XiaoYa,et al. The chemical and carbon isotopic compositions of volatiles in Cenozoic high-potassic basalts in western Qinling, China and their mantle geodynamic implications[J]. ACTA PETROLOGICA SINICA,2012,28(4):1251-1260. |
| APA | Tang QingYan,Zhang MingJie,Li XiaoYa,Li LiWu,He PeiPei,&Lin Yao.(2012).The chemical and carbon isotopic compositions of volatiles in Cenozoic high-potassic basalts in western Qinling, China and their mantle geodynamic implications.ACTA PETROLOGICA SINICA,28(4),1251-1260. |
| MLA | Tang QingYan,et al."The chemical and carbon isotopic compositions of volatiles in Cenozoic high-potassic basalts in western Qinling, China and their mantle geodynamic implications".ACTA PETROLOGICA SINICA 28.4(2012):1251-1260. |
入库方式： OAI收割
来源：地质与地球物理研究所
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