Abstract
Hydrous magnesium silicate phase D plays a key role in the transport of water from the upper to the lower mantle via subducted slabs. Here we report pressure dependence hyperfine and lattice parameters of FeAl-bearing phase D up to megabar pressures using synchrotron nuclear forward scattering and X-ray diffraction in a diamond anvil cell at room temperature. FeAl-bearing phase D undergoes a two-stage high-spin to low-spin transition of iron for Fe2+ at 37–41 GPa and for Fe3+ at 64–68 GPa. These transitions are accompanied by an increase in density and a significant softening in the bulk modulus and bulk velocity at their respective pressure range. The occurrence of the dense low-spin FeAl-bearing phase D with relatively high velocity anisotropies in deep-subducted slabs can potentially contribute to small-scale seismic heterogeneities in the middle-lower mantle beneath the circum-Pacific area.
| Original language | English |
|---|---|
| Pages (from-to) | 6411-6420 |
| Number of pages | 10 |
| Journal | Journal of Geophysical Research: Solid Earth |
| Volume | 121 |
| Issue number | 9 |
| DOIs | |
| Publication status | Published - Sep 1 2016 |
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Keywords
- lower mantle
- phase D
- spin transition of iron
ASJC Scopus subject areas
- Geophysics
- Oceanography
- Forestry
- Ecology
- Aquatic Science
- Water Science and Technology
- Soil Science
- Geochemistry and Petrology
- Earth-Surface Processes
- Atmospheric Science
- Earth and Planetary Sciences (miscellaneous)
- Space and Planetary Science
- Palaeontology
Cite this
Two-stage spin transition of iron in FeAl-bearing phase D at lower mantle. / Wu, Xiang; Wu, Ye; Lin, Jung Fu; Liu, Jin; Mao, Zhu; Guo, Xinzhuan; Yoshino, Takashi; McCammon, Catherine; Prakapenka, Vitali B.; Xiao, Yuming.
In: Journal of Geophysical Research: Solid Earth, Vol. 121, No. 9, 01.09.2016, p. 6411-6420.Research output: Contribution to journal › Article
}
TY - JOUR
T1 - Two-stage spin transition of iron in FeAl-bearing phase D at lower mantle
AU - Wu, Xiang
AU - Wu, Ye
AU - Lin, Jung Fu
AU - Liu, Jin
AU - Mao, Zhu
AU - Guo, Xinzhuan
AU - Yoshino, Takashi
AU - McCammon, Catherine
AU - Prakapenka, Vitali B.
AU - Xiao, Yuming
PY - 2016/9/1
Y1 - 2016/9/1
N2 - Hydrous magnesium silicate phase D plays a key role in the transport of water from the upper to the lower mantle via subducted slabs. Here we report pressure dependence hyperfine and lattice parameters of FeAl-bearing phase D up to megabar pressures using synchrotron nuclear forward scattering and X-ray diffraction in a diamond anvil cell at room temperature. FeAl-bearing phase D undergoes a two-stage high-spin to low-spin transition of iron for Fe2+ at 37–41 GPa and for Fe3+ at 64–68 GPa. These transitions are accompanied by an increase in density and a significant softening in the bulk modulus and bulk velocity at their respective pressure range. The occurrence of the dense low-spin FeAl-bearing phase D with relatively high velocity anisotropies in deep-subducted slabs can potentially contribute to small-scale seismic heterogeneities in the middle-lower mantle beneath the circum-Pacific area.
AB - Hydrous magnesium silicate phase D plays a key role in the transport of water from the upper to the lower mantle via subducted slabs. Here we report pressure dependence hyperfine and lattice parameters of FeAl-bearing phase D up to megabar pressures using synchrotron nuclear forward scattering and X-ray diffraction in a diamond anvil cell at room temperature. FeAl-bearing phase D undergoes a two-stage high-spin to low-spin transition of iron for Fe2+ at 37–41 GPa and for Fe3+ at 64–68 GPa. These transitions are accompanied by an increase in density and a significant softening in the bulk modulus and bulk velocity at their respective pressure range. The occurrence of the dense low-spin FeAl-bearing phase D with relatively high velocity anisotropies in deep-subducted slabs can potentially contribute to small-scale seismic heterogeneities in the middle-lower mantle beneath the circum-Pacific area.
KW - lower mantle
KW - phase D
KW - spin transition of iron
UR - http://www.scopus.com/inward/record.url?scp=84987950392&partnerID=8YFLogxK
UR - http://www.scopus.com/inward/citedby.url?scp=84987950392&partnerID=8YFLogxK
U2 - 10.1002/2016JB013209
DO - 10.1002/2016JB013209
M3 - Article
AN - SCOPUS:84987950392
VL - 121
SP - 6411
EP - 6420
JO - Journal of Geophysical Research
JF - Journal of Geophysical Research
SN - 0148-0227
IS - 9
ER -