Study of seismic tomography in Panxi paleorift area of southwestern China - Structural features of crust and mantle and their evolution
文献类型：期刊论文
| 作者 | Liu, JH; Liu, FT; He, JK; Chen, H; You, QY |
| 刊名 | SCIENCE IN CHINA SERIES D-EARTH SCIENCES
 |
| 出版日期 | 2001-03-01 |
| 卷号 | 44期号:3页码:277-+ |
| 关键词 | Panxi paleorift seismic tomography underplating of mantle material high-velocity anomaly body in mantle lithosphere |
| ISSN号 | 1006-9313 |
| 文献子类 | Article |
| 英文摘要 | Structural features of the typical continental paleorift in Panxi area are revealed by seismic tomography (1) In the profile along the minor axis of Panxi paleorift, we found alternating high and low-velocity strips existing at different depths in the crust, presenting itself as a "sandwich" structure. The existence of these high and low-velocity anomaly strips is related to the basal lithology in the rift area. (2) An addition layer with velocity values of 7.1-7.5 km/s and 7.8 km/s exists from the base of lower crust to uppermost mantle and its thickness is about 20 km. Some study results indicate that the addition layer results from the invasion of mantle material. (3) A lens-shaped high-velocity body surrounded by relatively low-velocity material is observed at depths of 110-160 km between Huaping and Huidong in the axis of the paleorift. This is the first time to discover it in the upper mantle of the paleorift. Based on the results of geology, petrology and geochemistry, we infer that the formation of the addition layer and the lens-shaped high-velocity body in the upper mantle are related to the deep geodynamic process of generation, development and termination of the rift. On the one hand, the upwelling of asthenosphere mantle caused partial melting, and then the basaltic magma from the partial melted material further resulted in underplating and formed the crustal addition layer. On the other hand, the high-density content of mineral facies was increased in the residual melted mass of intensely depleted upper mantle, formed by basalt withdrawing. The solid-melt medium in the depleted upper mantle was mainly an accumulation of garnet and peridotite because the heating effect of lithosphere was relatively weakened in the later riftogenesis, so that a lens-shaped high-density and high-velocity zone was produced in the upper mantle. The results indicate that the energy and material exchange between asthenosphere and lithosphere and remarkable underplating would have an important effect on the material state and propagation of seismic wave in the lower crust, crust-mantle interface, asthenosphere and lithosphere. This process possibly is an important mechanism on the growth of continental crust and the evolution of deep mantle. |
| WOS关键词 | MECHANISM |
| WOS研究方向 | Geology |
| 语种 | 英语 |
| WOS记录号 | WOS:000168219600010 |
| 出版者 | SCIENCE PRESS |
| 源URL | [http://ir.iggcas.ac.cn/handle/132A11/76673]  |
| 专题 | 中国科学院地质与地球物理研究所 |
| 通讯作者 | Liu, JH |
| 作者单位 | Chinese Acad Sci, Inst Geol & Geophys, Beijing 100101, Peoples R China |
| 推荐引用方式 GB/T 7714 | Liu, JH,Liu, FT,He, JK,et al. Study of seismic tomography in Panxi paleorift area of southwestern China - Structural features of crust and mantle and their evolution[J]. SCIENCE IN CHINA SERIES D-EARTH SCIENCES,2001,44(3):277-+. |
| APA | Liu, JH,Liu, FT,He, JK,Chen, H,&You, QY.(2001).Study of seismic tomography in Panxi paleorift area of southwestern China - Structural features of crust and mantle and their evolution.SCIENCE IN CHINA SERIES D-EARTH SCIENCES,44(3),277-+. |
| MLA | Liu, JH,et al."Study of seismic tomography in Panxi paleorift area of southwestern China - Structural features of crust and mantle and their evolution".SCIENCE IN CHINA SERIES D-EARTH SCIENCES 44.3(2001):277-+. |
入库方式： OAI收割
来源：地质与地球物理研究所
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