| Citation: | Xiong Xiong, Houtze Hsu, Jiwen Teng. Cold Thermal Anomalous Structure within Lower Mantle and Its Geodynamic Implications. Journal of Earth Science, 2001, 12(2): 160-164.
|
The lateral temperature a nomalous structure of the lower mantle is reconstructed from the seismic tomographical model and high temperature and high pressure laboratory results. A significant correlation between the distribution of the cold anomaly and the location of past subduction belts shows that the shallower anomaly corresponds to the younger subduction sites, while the deeper anomaly to the older ones.This correlation also suggests that the cold anomaly may have come from the subduction slabs and the scale of mantle convection may have been completed.The coldest and largest anomaly is concentrated near the core-mantle boundary (CMB). Few cold anomalies float in the shallower and middle parts of the lower mantle, suggesting that the downward migration of the subduction slabs, discontinuous and step-like, may be divided into the following three stages: subduction, stagnation at the 670 km discontinuity due to the phase transition, and disintegration when the size exceeds the critical point.
| Chopelas R, Boeh ler R, 1989. Thermal Expansion Measurements at Very High Pressure, S ystematics and a Case for a C hemically Homogeneous Mantle. Geophys Res Lett, 16: 1347-1350 doi: 10.1029/GL016i011p01347 |
| Chopelas R, Boehler R, 1992. Thermal Expansivity of the Lower Mantle. Geophys Res Lett, 19: 1983-1986 doi: 10.1029/92GL02144 |
| Feng R, 1994. Global S eismic Tomography. In: Wang J, ed. Symposium of Seminar on Present Geodynamic Problems. Beijing : Seismological Press. 19-25 (in Chinese) |
| Fu R S, Huang J H, Liu W Z, 1993. Study on Lateral Heterogeneity of Density Distribution within the Earth' s In terior. Acta Geophysia Sinica, 36: 740-752 |
| Honda S, Balachandar S, Yuen D A, et al, 1993. Th ree-Dimensional Man tle Dynamics w ith an Endothermic Phase Transition. Geophys Res Lett, 20: 221-224 |
| Li X L, 1995. Study on Mechanism of Geoid and Lateral Heterogeneity w ithin the Earth' s Interior: [Dissertation]. Wuhan: Institute of Geodesy and Geophysics, Chinese Academy of Sciences |
| Maruyama S, 1994. Plume T ectonics. J Geol S oc Japan, 100: 24-49 doi: 10.5575/geosoc.100.24 |
| Richards M A, Engeb reston D C, 1992. Large-Scale Mantle Convection and the History of Subduction. Nature, 355: 437-440 doi: 10.1038/355437a0 |
| Su W J, Woodw ard R L, Dziewonski A M, 1994. Degree -12 Model of Shear Velocity Heterogeneity in the Mantle. J G R, 99: 11231 - 11250 |
| Tong J, 1994. Thermal Anomalies and the S tructure of M antle Convection: [ Dissertation]. Hefei: China University of Science and Technology |
| Yuen D A, Cadek O, Chopelas A, et al, 1993. Geophysical Inferences of Thermal-Chemical S tructures in the Low er Mantle. Geophys Res Lett, 20(10) : 899-902 doi: 10.1029/93GL00867 |
| Zhang Y S, 1994. Velocity S tructure of the Upper Mantle beneath Tibetan Plateau and Its Adjacent Area and Geodynamic S tudy. In: Chen Y, ed. Progress of S olid Earth Geophysics in China. Beijing : Seismological Press. 150-161 (in Chinese with English Abstract) |
| Zhang Y S, Tanimoto T, 1992. Ridges, Hotspots and Their Interaction as Observed in S eismic Velocity Maps. Nature, 355: 45-49 doi: 10.1038/355045a0 |
| Zhang Y S, T animoto T, 1993. High Resolu tion Global Upper M antle Structu re : Plate Tectonics. J G R, 98: 9793-9823 |
Figures(3)
Copyright © 2013-2020 Journal of Earth Science 鄂ICP备15021562号-2
Tel: +86-27-67885075 Fax: +86-27-67885075 E-mail: xbb@cug.edu.cn
Address: Editorial Office of Journal, China University of Geosciences, Yujiashan, Wuhan, Hubei 430074, P. R. China
Supported by:
Beijing Renhe Information Technology Co. Ltd
E-mail:
info@rhhz.net
DownLoad:
