DOI: 10.1016/j.epsl.2018.05.031
Scopus记录号: 2-s2.0-85047734218
论文题名: The combined effects of post-spinel and post-garnet phase transitions on mantle plume dynamics
作者: Liu H. ; Wang W. ; Jia X. ; Leng W. ; Wu Z. ; Sun D.
刊名: Earth and Planetary Science Letters
ISSN: 0012821X
出版年: 2018
卷: 496 起始页码: 80
结束页码: 88
语种: 英语
英文关键词: dynamics
; geodynamic modeling
; mantle plume
; phase transitions
Scopus关键词: Geodynamics
; Perovskite
; Phase boundaries
; Phase transitions
; Seismic waves
; Seismology
; Temperature
; Thermal plumes
; Wave propagation
; Geodynamic modeling
; Geodynamical modeling
; Mantle plume
; Mantle temperatures
; Mantle transition zone
; Seismic observation
; Seismic wave velocity
; Truncated cone shape
; Dynamics
; garnet
; geodynamics
; mantle plume
; modeling
; phase transition
; seismic velocity
; spinel
英文摘要: Mineralogical studies indicate that two major phase transitions occur near the depth of 660 km in the Earth's pyrolitic mantle: the ringwoodite (Rw) to perovskite (Pv) + magnesiowüstite (Mw) and the majorite (Mj) to perovskite (Pv) phase transitions. Seismological results also show a complicated phase boundary structure at this depth in plume regions. However, previous geodynamical modeling has mainly focused on the effects of the Rw–Pv+Mw phase transition on plume dynamics and has largely neglected the effects of the Mj–Pv phase transition. Here, we develop a 3-D regional spherical geodynamic model to study the combined influence of these two phase transitions on plume dynamics. Our results show the following: (1) A double phase boundary occurs in the high-temperature center of the plume, corresponding to the double reflections in seismic observations. Other plume regions feature a single, flat uplifted phase boundary, causing a gap of high seismic velocity anomalies. (2) Large amounts of relatively low-temperature plume materials can be trapped in the transition zone due to the combined effects of phase transitions, forming a complex truncated cone shape. (3) The Mj–Pv phase transition greatly enhances the plume penetration capability through 660-km phase boundary, which has a significant influence on the plume dynamics. Our results provide new insights which can be used to better constrain the 660-km discontinuity variations, seismic wave velocity structure and plume dynamics in the mantle transition zone. The model can also help to estimate the mantle temperature and Clapeyron slopes at the 660 km phase boundary. © 2018 Elsevier B.V. Citation statistics:
资源类型: 期刊论文
标识符: http://119.78.100.158/handle/2HF3EXSE/109811
Appears in Collections: 影响、适应和脆弱性 气候变化事实与影响
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作者单位: Laboratory of Seismology and Physics of Earth's Interior, School of Earth and Space Sciences, University of Science and Technology of China, Hefei, 230026, China; National Geophysical Observatory at Mengcheng, University of Science and Technology of China, Anhui, China
Recommended Citation:
Liu H.,Wang W.,Jia X.,et al. The combined effects of post-spinel and post-garnet phase transitions on mantle plume dynamics[J]. Earth and Planetary Science Letters,2018-01-01,496