DOI: 10.1016/j.epsl.2020.116345
论文题名: The seismically fastest chemical heterogeneity in the Earth's deep upper mantle—implications from the single-crystal thermoelastic properties of jadeite
作者: Hao M. ; Zhang J.S. ; Pierotti C.E. ; Zhou W.-Y. ; Zhang D. ; Dera P.
刊名: Earth and Planetary Science Letters
ISSN: 0012821X
出版年: 2020
卷: 543 语种: 英语
中文关键词: continent-derived sediments/crust
; enriched geochemical reservoirs
; jadeite
; seismic velocity
; single-crystal elasticity
英文关键词: Elasticity
; Equations of state of solids
; Geochemistry
; Sediments
; Seismic waves
; Seismology
; Silicate minerals
; Single crystals
; Thermoelasticity
; Birch-Murnaghan equation of state
; Chemical heterogeneities
; Finite strain equations
; Geochemical heterogeneity
; High-pressure condition
; Single crystal x-ray diffraction
; Temperature conditions
; Thermoelastic properties
; Crystal symmetry
; heterogeneity
; high pressure
; jadeite
; seismic velocity
; subduction
; temperate environment
; thermoelasticity
; upper mantle
英文摘要: Jadeite is a major mineral phase (up to 50 vol%) in the subducted sediments/crust with continental origin, which are one of the major heterogeneities and important enriched geochemical reservoirs (such as EM-1 and EM-2) for incompatible elements in the Earth's interior. Identifying and locating the enriched geochemical heterogeneities requires knowledge of the elastic properties of relevant mineral phases at high pressure-temperature conditions. Unfortunately, the single-crystal elastic properties of jadeite have never been measured at high-pressure conditions, partially due to its low crystal symmetry. In this study, we have experimentally determined the single-crystal elastic moduli of jadeite at high pressures for the first time up to 18 GPa at the ambient temperature condition using Brillouin spectroscopy. Fitting the third-order finite strain equation of state to the velocity-pressure data yields KS0 ′=3.9(1), G0 ′=1.09(4) with ρ0=3.302(5) g/cm3, KS0=138(3) GPa, and G0=84(2) GPa. In addition, we have also conducted synchrotron single-crystal X-ray diffraction experiments up to 25 GPa and 700 K. The fitting of a Holland-Powell type thermal-pressure Birch-Murnaghan equation of state yields KT0 ′=3.8(2) and α0=3.4(5) ×10−5 K−1. Based on the obtained thermoelastic parameters of jadeite, the density and seismic velocities of continent-derived sediments/crust are modeled at the depth range from 200 to 500 km. The seismic velocities of the subducted continental sediments/crust become extremely fast at depths greater than ∼300 km, up to 11.8% and 14.7% faster than the Vp and Vs of the ambient mantle, and 5.6% and 7.3% faster than the Vp and Vs of the subducted oceanic crust. The existence of even a small amount of the subducted continental sediments/crust can result in strong seismic anomalies in the Earth's interior. © 2020 Elsevier B.V. Citation statistics:
资源类型: 期刊论文
标识符: http://119.78.100.158/handle/2HF3EXSE/165009
Appears in Collections: 气候变化与战略
There are no files associated with this item.
作者单位: Department of Earth and Planetary Sciences, University of New Mexico, Albuquerque, NM 87131, United States; Institute of Meteoritics, University of New Mexico, Albuquerque, NM 87131, United States; Albuquerque High School, Albuquerque, NM 87102, United States; Hawaii Institute of Geophysics and Planetology, University of Hawaii at ManoaHI 96822, United States; GeoSoiEnviroCARS, University of Chicago, Argonne National Laboratory, Argonne, IL 60439, United States
Recommended Citation:
Hao M.,Zhang J.S.,Pierotti C.E.,et al. The seismically fastest chemical heterogeneity in the Earth's deep upper mantle—implications from the single-crystal thermoelastic properties of jadeite[J]. Earth and Planetary Science Letters,2020-01-01,543