|
|
Hokkaido University Collection of Scholarly and Academic Papers >
Graduate School of Science / Faculty of Science >
Peer-reviewed Journal Articles, etc >
Water partitioning in the Earth's mantle
| Title: | Water partitioning in the Earth's mantle |
| Authors: | Inoue, Toru Browse this author | | Wada, Tomoyuki Browse this author | | Sasaki, Rumi Browse this author | | Yurimoto, Hisayoshi Browse this author |
| Keywords: | Mantle | | Olivine | | Wadsleyite | | Ringwoodite | | Perovskite | | Hydrous wadsleyite | | Hydrous ringwoodite | | High pressure phase transformation | | Partitioning of H2O |
| Issue Date: | Nov-2010 |
| Publisher: | Elsevier B.V. |
| Journal Title: | Physics of the Earth and Planetary Interiors |
| Volume: | 183 |
| Issue: | 1-2 |
| Start Page: | 245 |
| End Page: | 251 |
| Publisher DOI: | 10.1016/j.pepi.2010.08.003 |
| Abstract: | We have conducted H2O partitioning experiments between wadsleyite and ringwoodite and between ringwoodite and perovskite at 1673 K and 1873 K, respectively. These experiments were performed in order to constrain the relative distribution of H2O in the upper mantle, the mantle transition zone, and the lower mantle. We successfully synthesized coexisting mineral assemblages of wadsleyite-ringwoodite and ringwoodite-perovskite that were large enough to measure the H2O contents by secondary ion mass spectrometry (SIMS). Combining our previous H2O partitioning data (Chen et al., 2002) with the present results, the determined water partitioning between olivine, wadsleyite, ringwoodite, and perovskite under H2O-rich fluid saturated conditions are 6:30:15:1, respectively. Because the maximum H2O storage capacity in wadsleyite is ∼3.3 wt% (e.g. Inoue et al., 1995), the possible maximum H2O storage capacity in the olivine high pressure polymorphs are as follows: ∼0.7 wt% in olivine (upper mantle just above 410 km depth), ∼3.3 wt% in wadsleyite (410-520 km depth), ∼1.7 wt% in ringwoodite (520-660 km depth), and ∼0.1 wt% in perovskite (lower mantle). If we assume ∼0.2 wt% of the H2O content in wadsleyite in the mantle transition zone estimated by recent electrical conductivity measurements (e.g. Dai and Karato, 2009), the estimated H2O contents throughout the mantle are as follows; ∼0.04 wt% in olivine (upper mantle just above 410 km depth), ∼0.2 wt% in wadsleyite (410-520 km depth), ∼0.1 wt% in ringwoodite (520-660 km depth) and ∼0.007 wt% in perovskite (lower mantle). Thus, the mantle transition zone should contain a large water reservoir in the Earth's mantle compared to the upper mantle and the lower mantle. |
| Type: | article (author version) |
| URI: | http://hdl.handle.net/2115/44920 |
| Appears in Collections: | 理学院・理学研究院 (Graduate School of Science / Faculty of Science) > 雑誌発表論文等 (Peer-reviewed Journal Articles, etc)
|
Submitter: 圦本 尚義
|
