| Item type |
デフォルトアイテムタイプ_（フル）(1) |
| 公開日 |
2023-03-18 |
| タイトル |
|
|
タイトル |
Precise determination of phase relations in pyrolite across the 660 km seismic discontinuity by in situ X-ray diffraction and quench experiments |
|
言語 |
en |
| 作成者 |
Nishiyama, Norimasa
Irifune, Tetsuo
Inoue, Toru
Ando, Jun-ichi
Funakoshi, Ken-ichi
|
| アクセス権 |
|
|
アクセス権 |
open access |
|
アクセス権URI |
http://purl.org/coar/access_right/c_abf2 |
| 権利情報 |
|
|
権利情報 |
Copyright (c) 2004 Published by Elsevier Science B.V. |
| 主題 |
|
|
主題Scheme |
Other |
|
主題 |
Pyrolite |
| 主題 |
|
|
主題Scheme |
Other |
|
主題 |
660 km seismic discontinuity |
| 主題 |
|
|
主題Scheme |
Other |
|
主題 |
Ringwoodite |
| 主題 |
|
|
主題Scheme |
Other |
|
主題 |
Majorite garnet |
| 主題 |
|
|
主題Scheme |
Other |
|
主題 |
In situ X-ray diffraction experiments |
| 主題 |
|
|
主題Scheme |
Other |
|
主題 |
Fe–Mg partitioning |
| 主題 |
|
|
主題Scheme |
NDC |
|
主題 |
450 |
| 内容記述 |
|
|
内容記述 |
Mineral assemblage changes in a pyrolite composition with increasing pressure were observed by in situ X-ray diffraction and quench experiments at pressures near that of the 660 km seismic discontinuity and at a fixed temperature of 1600 °C. According to results obtained by in situ X-ray diffraction experiments, ringwoodite (Rw) was observed with majorite garnet and CaSiO3-rich perovskite at pressures of about 20–22 GPa. Dissociation of ringwoodite to MgSiO3-rich perovskite and magnesiowüstite (Mw) was completed at 22.0±0.2 GPa according to Matsui et al.'s periclase pressure scale, and at 21.7±0.1 GPa according to Shim et al.'s gold pressure scale. Majorite garnet persisted to about 24 GPa where pyrolite transformed to a lower mantle mineral assemblage, i.e. MgSiO3-perovskite, CaSiO3-rich perovskite, and magnesiowüstite. Thus, majorite garnet coexists with the lower mantle assemblage at pressures of about 22–24 GPa. In the quench experiments, an assemblage of MgSiO3-perovskite, magnesiowüstite, CaSiO3-rich perovskite, and majorite garnet was synthesized at 22.5 GPa and 1600 °C, in which Mg-perovskite contained 2.8 wt.% Al2O3, and was significantly poorer in Fe than coexisting magnesiowüstite. The Fe–Mg partition coefficient between Mg-perovskite and magnesiowüstite including ferric iron (Kapp=0.27±0.06) is very close to that in the Al-free system, which suggests that these P–T conditions are in the vicinity of those of ringwoodite decomposition. Both the results of in situ X-ray diffraction and quench experiments in the present study yield a convergent result that ringwoodite decomposes into Mg-perovskite and magnesiowüstite before the garnet-to-perovskite transition at 1600 °C in pyrolite. The relation between the Al content in Mg-perovskite and Kapp in pyrolite is non-linear, which is consistent with the Fe–Mg partitioning between Mg-perovskite and magnesiowüstite previously reported for a simpler MgO–FeO–Al2O3–SiO2 system. |
|
言語 |
en |
| 出版者 |
|
|
出版者 |
Elsevier |
| 言語 |
|
|
言語 |
eng |
| 資源タイプ |
|
|
資源タイプ識別子 |
http://purl.org/coar/resource_type/c_6501 |
|
資源タイプ |
journal article |
| 出版タイプ |
|
|
出版タイプ |
AO |
|
出版タイプResource |
http://purl.org/coar/version/c_b1a7d7d4d402bcce |
| 関連情報 |
|
|
|
識別子タイプ |
DOI |
|
|
関連識別子 |
10.1016/j.pepi.2003.08.010 |
| 関連情報 |
|
|
|
識別子タイプ |
DOI |
|
|
関連識別子 |
http://dx.doi.org/10.1016/j.pepi.2003.08.010 |
| 収録物識別子 |
|
|
収録物識別子タイプ |
ISSN |
|
収録物識別子 |
0031-9201 |
| 収録物識別子 |
|
|
収録物識別子タイプ |
NCID |
|
収録物識別子 |
AA00773963 |
| 開始ページ |
|
|
開始ページ |
185 |
| 書誌情報 |
Physics of The Earth and Planetary Interiors
Physics of The Earth and Planetary Interiors
巻 143-144,
p. 185-199,
発行日 2004-06-15
|
| 旧ID |
21537 |
PEPI_143-144_185.pdf (1.6 MB)
