The effect of mantle thermal conductivity on dynamic numerical modeling: a case study of lithospheric extension
文献类型：期刊论文
| 作者 | Shen YongQiang2,3,5; Shi XiaoBin2,3; Liao Jie4; Xu HeHua2,3; Ren ZiQiang2,3,5 |
| 刊名 | CHINESE JOURNAL OF GEOPHYSICS-CHINESE EDITION
 |
| 出版日期 | 2020 |
| 卷号 | 63期号:5页码:1998 |
| 关键词 | Mantle thermal conductivity Lithospheric extension Thermo-mechanical modeling Lithospheric strength Crust and mantle melting |
| DOI | 10.6038/cjg2020N0372 |
| 英文摘要 | So far multiple models of mantle thermal conductivity with different values and featured distribution with depth have been proposed, and some of them has already been applied in thermo-mechanic modeling. The effect of thermal conductivity on numerical modeling, however, still remains unclear. In this study, using two-dimensional thermo-mechanical model, we investigate the lithospheric extension process with different mantle thermal conductivity models, and discuss the impacts of different thermal conductivity models on heat transfer, lithospheric deformation and melting process. The results show that, with different models of mantle thermal conductivity, the characteristics of lithospheric deformation and melting of various numerical models are obviously distinct from each other. Models with a higher thermal conductivity are often featured by later breakup of lithosphere, wider continental margin and intense lower crust melting whereas weak melting of mantle; while models with a lower thermal conductivity often behave as earlier breakup of lithosphere, narrower continental margin and intense mantle melting whereas weak melting of lower crust. These distinct differences are mainly caused by the change of thermal state and mechanical properties of lithosphere or mantle under the control of different mantle thermal conductivity models. With higher mantle thermal conductivity, the Moho temperature elevated by thermal conduction is larger, which lowers the strength of the entire lithosphere and decouples crust and mantle strongly. As a consequence, the strain distributes more evenly and lithospheric thinning rate decreases, which leads a longer stretching stage and wider continental margin. On the contrary, with lower thermal conductivity, the temperature elevated by thermal conduction is smaller, which makes lithosphere stronger than models of higher thermal conductivity except for the region of high strain rates where mantle advection is more intense and the temperature elevated is higher. As a consequence, the strain distributes more centered and lithospheric thinning rate increases, which lead a shorter stretching stage and narrower continental margin. With respect to melting, high conductive heat of higher thermal conductivity model makes it possible for lower crust to be molten and even increases the melt with time, but the high heat loss and lower-rate decompression process in mantle suppress the melting of asthenosphere and even terminate it. But as for lower thermal conductivity model, the melting behavior of crust and mantle is totally opposite to higher thermal conductivity models, with more melt in mantle whereas less or even no melt in lower crust. Based on the results, we argue that mantle thermal conductivity may have greater effect on numerical modeling than we thought before, and compared with the effect of thermal conductivity varying with temperature and pressure, the value of thermal conductivity will bring more influence, especially on modeling of melting process. |
| 源URL | [http://ir.scsio.ac.cn/handle/344004/18550]  |
| 专题 | 南海海洋研究所_中科院边缘海地质重点实验室 |
| 作者单位 | 1.Univ Chinese Acad Sci, Beijing 100049, Peoples R China 2.Chinese Acad Sci, South China Sea Inst Oceanol, Key Lab Ocean & Marginal Sea Geol, Guangzhou 510301, Peoples R China 3.Chinese Acad Sci, Innovat Acad South China Sea Ecol & Environm Engn, Guangzhou 510301, Peoples R China 4.Southern Marine Sci & Engn Guangdong Lab Guangzho, Guangzhou 510301, Peoples R China 5.Sun Yat Sen Univ, Sch Earth Sci & Engn, Guangzhou 510275, Peoples R China |
| 推荐引用方式 GB/T 7714 | Shen YongQiang,Shi XiaoBin,Liao Jie,et al. The effect of mantle thermal conductivity on dynamic numerical modeling: a case study of lithospheric extension[J]. CHINESE JOURNAL OF GEOPHYSICS-CHINESE EDITION,2020,63(5):1998, 2012. |
| APA | Shen YongQiang,Shi XiaoBin,Liao Jie,Xu HeHua,&Ren ZiQiang.(2020).The effect of mantle thermal conductivity on dynamic numerical modeling: a case study of lithospheric extension.CHINESE JOURNAL OF GEOPHYSICS-CHINESE EDITION,63(5),1998. |
| MLA | Shen YongQiang,et al."The effect of mantle thermal conductivity on dynamic numerical modeling: a case study of lithospheric extension".CHINESE JOURNAL OF GEOPHYSICS-CHINESE EDITION 63.5(2020):1998. |
入库方式： OAI收割
来源：南海海洋研究所
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