Permian volcanism in the Mongolian orogenic zone, northeast China: geochemistry, magma sources and petrogenesis
文献类型：期刊论文
| 作者 | Zhu, YF; Sun, SH; Gu, LB; Ogasawara, Y; Jiang, N; Honma, H |
| 刊名 | GEOLOGICAL MAGAZINE
 |
| 出版日期 | 2001-03-01 |
| 卷号 | 138期号:2页码:101-115 |
| ISSN号 | 0016-7568 |
| 文献子类 | Article |
| 英文摘要 | Lower Permian volcanism was the first magmatic activity to occur after the collision events in the Mongolian orogenic zone, east China. The Permian volcanic rocks are therefore a key to understanding the dynamics of the unified continental lithosphere. The volcanic rocks consist of basic and intermediate rocks. The intermediate rocks with high initial (87)Sr/(86)Sr ratios (0.7051 to 0.7052) and low epsilon (Nd) values (-0.73 to -3.57) generally overlie the basic rocks in the field. The basic rocks have relatively low initial (87)Sr/(86)Sr ratios (0.7034 to 0.7051) and high epsilon (Nd) values (2.72 to -0.10). Two parallel Rb-Sr isochrons give almost the same age, about 270 Ma. One consists of the basic rocks giving an initial isochron (87)Sr/(86)Sr ratio of 0.7035. The other consists of the intermediate rocks and one sample of basalt, which give an initial isochron (87)Sr/(86)Sr value of 0.7051. The strong correlations between SiO(2) and other major elements suggest that fractional crystallization Flayed an important role in the magmatic processes. However, fractional crystallization cannot explain the geochemistry of most incompatible trace elements and Sr-Nd isotope characteristics. The positive correlation between Th/Nb and (La/Sm)(N) ratios demonstrates the direct relation between the enrichment of the light rare earth elements and the contamination of continental sediments. The high contents of large ion lithosphere elements (LILE) in the Permian volcanic rocks may suggest an additional 'crust + fluid' component, especially in the intermediate rocks, which are highly enriched in Ba (> 400 ppm) relative to the basic rocks (< 200 ppm). We propose that the subduction slab dropped into depleted mantle and released fluid, which induced the mantle metasomatism and LILE enrichment. The metasomatized mantle partially melted and formed the 'primary' magma. This primary magma assimilated with the Proterozoic biotite-quartz schist during its rise, and finally formed the Permian volcanic rocks. Magma assimilated with the Proterozoic biotite-quartz schist in small amounts could have produced the basic rocks, while assimilation of larger amounts of magma (because of longer assimilation time) would generate intermediate rocks. |
| WOS关键词 | TRACE-ELEMENT ; CRYSTAL FRACTIONATION ; CONTINENTAL-CRUST ; INNER-MONGOLIA ; OCEANIC-CRUST ; TIME SCALES ; MANTLE ; CONSTRAINTS ; EVOLUTION ; LITHOSPHERE |
| WOS研究方向 | Geology |
| 语种 | 英语 |
| WOS记录号 | WOS:000168367200001 |
| 出版者 | CAMBRIDGE UNIV PRESS |
| 源URL | [http://ir.iggcas.ac.cn/handle/132A11/77067]  |
| 专题 | 中国科学院地质与地球物理研究所 |
| 通讯作者 | Zhu, YF |
| 作者单位 | 1.Peking Univ, Dept Geol, Beijing 100871, Peoples R China 2.Chinese Acad Sci, Inst Geol & Geophys, Beijing 100029, Peoples R China 3.Waseda Univ, Dept Earth Sci, Tokyo 16950, Japan |
| 推荐引用方式 GB/T 7714 | Zhu, YF,Sun, SH,Gu, LB,et al. Permian volcanism in the Mongolian orogenic zone, northeast China: geochemistry, magma sources and petrogenesis[J]. GEOLOGICAL MAGAZINE,2001,138(2):101-115. |
| APA | Zhu, YF,Sun, SH,Gu, LB,Ogasawara, Y,Jiang, N,&Honma, H.(2001).Permian volcanism in the Mongolian orogenic zone, northeast China: geochemistry, magma sources and petrogenesis.GEOLOGICAL MAGAZINE,138(2),101-115. |
| MLA | Zhu, YF,et al."Permian volcanism in the Mongolian orogenic zone, northeast China: geochemistry, magma sources and petrogenesis".GEOLOGICAL MAGAZINE 138.2(2001):101-115. |
入库方式： OAI收割
来源：地质与地球物理研究所
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