Investigation on viscosity anomaly at ~1000 km depth and constraints on the chemistry in the lower mantle

• Project/Area Number: 17H01173
• Research Category: Grant-in-Aid for Scientific Research (A)
• Allocation Type: Single-year Grants
• Section: 一般
• Research Field: Petrology/Mineralogy/Economic geology
• Research Institution: Okayama University
• Principal Investigator: Yamazaki Daisuke 岡山大学, 惑星物質研究所, 准教授 (90346693)
• Co-Investigator(Kenkyū-buntansha): 辻野 典秀 岡山大学, 惑星物質研究所, 助教 (20633093) ; 芳野 極 岡山大学, 惑星物質研究所, 教授 (30423338) ; 米田 明 岡山大学, 惑星物質研究所, 客員研究員 (10262841)
• Project Period (FY): 2017-04-01 – 2021-03-31
• Project Status: Completed (Fiscal Year 2020)
• Budget Amount: ¥44,590,000 (Direct Cost: ¥34,300,000、Indirect Cost: ¥10,290,000); Fiscal Year 2020: ¥5,330,000 (Direct Cost: ¥4,100,000、Indirect Cost: ¥1,230,000); Fiscal Year 2019: ¥10,920,000 (Direct Cost: ¥8,400,000、Indirect Cost: ¥2,520,000); Fiscal Year 2018: ¥11,310,000 (Direct Cost: ¥8,700,000、Indirect Cost: ¥2,610,000); Fiscal Year 2017: ¥17,030,000 (Direct Cost: ¥13,100,000、Indirect Cost: ¥3,930,000)
• Keywords: 粘性率 / 化学組成 / 変形実験 / 下部マントル / 鉱物組み合わせ / 微細構造 / 高圧実験 / 変形組織 / 地球内部構造 / 変形 / 拡散 / 地球・惑星内部構造

Outline of Final Research Achievements

Geophysical observation revealed that the viscosity increases by an order of magnitude at a depth of ~ 1000 km in the earth’s lower mantle. At a same depth of ~1000 km, the stagnation of the subducted slabs are observed in several subduction zones. To constrain the mechanism of the viscosity jump, the viscosity properties of the constituent minerals of the lower mantle were investigated by using an improved and newly installed high-pressure deformation apparatus for a mineral physics approach. As a result, it is likely that the contribution of ferropericrace, which is the secondary phase of lower mantle assembly, for the viscosity change is low, and the viscosity of bridgmanite itself is the key factor.

Academic Significance and Societal Importance of the Research Achievements

下部マントルの深さ1000kmに粘性率の著しい増加が観測されている。下部マントルを構成する鉱物の粘性特性を調査し、この観測と比較することで、下部マントルの鉱物組み合わせやさらには化学組成にこれまでと違った角度から制約を与えることが可能となる。研究の結果は、下部マントルはシリカに富んでいても観測とは矛盾しないという結果となった。下部マントルは地球の全体積の約6割を占めているので、今回の結果は、全地球の化学進化を考察する上でも重要な知見となる。

Research Products

• [Journal Article] Pressure generation in the Kawai-type multianvil apparatus and rheology of the Earth's interior (2020)
  • Author(s): YAMAZAKI Daisuke
  • Journal Title: Japanese Magazine of Mineralogical and Petrological Sciences Volume: 49 Issue: 1 Pages: 15-27
  • DOI: 10.2465/gkk.191226
  • NAID: 130007839825
  • ISSN: 1345-630X, 1349-7979
  • Peer Reviewed
• [Journal Article] Lattice preferred orientation of stishovite deformed at high pressure and high temperature (2020)
  • Author(s): Xu F.、Yamazaki D.、Tsujino N.、Guan L.
  • Journal Title: Physics of the Earth and Planetary Interiors Volume: 306 Pages: 106546-106546
  • DOI: 10.1016/j.pepi.2020.106546
  • Peer Reviewed / Int'l Joint Research
• [Journal Article] Formation of bridgmanite-enriched layer at the top lower-mantle during magma ocean solidification (2020)
  • Author(s): Xie, L., Yoneda, A., Yamazaki, D., Manthilake, G., Higo, Y., Tange, Y., Guignot, N., King, A., Scheel, M., Andrault, D.
  • Journal Title: Nature Communications Volume: 11 Pages: 1-10
  • DOI: 10.1038/s41467-019-14071-8
  • NAID: 120006884919
  • Peer Reviewed / Open Access / Int'l Joint Research
• [Journal Article] Pressure dependence of Si diffusion in γ-Fe (2020)
  • Author(s): Tsujino Noriyoshi、Marza Andreea、Yamazaki Daisuke
  • Journal Title: American Mineralogist Volume: 105 Pages: 319-324
  • DOI: 10.2138/am-2020-7197
  • NAID: 120007032765
  • Peer Reviewed / Int'l Joint Research
• [Journal Article] High pressure generation in the Kawai-type multianvil apparatus equipped with sintered diamond anvils (2019)
  • Author(s): Yamazaki D.、Ito E.
  • Journal Title: High Pressure Research Volume: 40 Pages: 3-11
  • DOI: 10.1080/08957959.2019.1689975
  • Peer Reviewed
• [Journal Article] Phase transition of wadsleyite-ringwoodite in the system Mg2SiO4-Fe2SiO4 (2019)
  • Author(s): N. Tsujino, T. Yoshino, D. Yamazaki, M. Sakurai, W. Sun, F. Xu, Y. Tange, Y. Higo
  • Journal Title: American Mineralogist Volume: 104 Pages: 588-594
  • DOI: 10.2138/am-2019-6823
  • Peer Reviewed / Int'l Joint Research
• [Journal Article] High-pressure generation in the Kawai-type multianvil apparatus equipped with tungsten-carbide anvils and sintered-diamond anvils, and X-ray observation on CaSnO3 and (Mg,Fe)SiO3 (2019)
  • Author(s): D. Yamazaki, E. Ito, T. Yoshino, N. Tsujino, A. Yoneda, H. Gomi, J. Vazhakuttiyakam, M. Sakurai, Y. Zhang, Y. Higo, Y. Tange
  • Journal Title: Comptes Rendus Geoscience Volume: 351 Pages: 253-253
  • DOI: 10.1016/j.crte.2018.07.004
  • Peer Reviewed / Open Access
• [Journal Article] Thermal expansion of natural mantle spinel using in situ synchrotron X-ray powder diffraction (2019)
  • Author(s): J. Yamamoto, T. Yoshino, D. Yamazaki, Y. Higo, Y. Tange, J. Torimoto
  • Journal Title: J. Mater. Sci. Volume: 54 Pages: 139-139
  • DOI: 10.1007/s10853-018-2848-5
  • Peer Reviewed
• [Journal Article] Crystal chemistry of Eu-bearing tuite synthesized at high-pressure and high-temperature conditions (2019)
  • Author(s): Zhai, S., Yang, H., Xue, W., Huang, E., Yamazaki, D., Morrison, S. M., Downs, R. T.
  • Journal Title: Phys. Chem. Miner. Volume: 46 Pages: 157-163
  • DOI: 10.1007/s00269-018-0994-6
  • Peer Reviewed / Int'l Joint Research
• [Journal Article] Negative activation volume of oxygen self-diffusion in forsterite (2018)
  • Author(s): Fei, H., Wiedenbeck, M., Sakamoto, N., Yurimoto, H., Yoshino, T., Yamazaki, D., Katsura, T.
  • Journal Title: Phys. Earth Planet. Inter. Volume: 275 Pages: 1-8
  • Peer Reviewed / Int'l Joint Research
• [Journal Article] Pressure generation to 65 GPa in a Kawai-type multi-anvil apparatus with tungsten carbide anvils (2017)
  • Author(s): Takayuki Ishii, Daisuke Yamazaki, Noriyoshi Tsujino, Fang Xu, Zhaodong Liu, Takaaki Kawazoe, Takafumi Yamamoto, Dmitry Druzhbin, Lin Wang, Yuji Higo, Yoshinori Tange, Takashi Yoshino, Tomoo Katsura
  • Journal Title: High Pressure Research Volume: 37 Pages: 507-515
  • DOI: 10.1080/08957959.2017.1375491
  • Peer Reviewed / Int'l Joint Research
• [Journal Article] A nearly water-saturated mantle transition zone inferred from mineral viscosity (2017)
  • Author(s): Fei Hongzhan、Yamazaki Daisuke、Sakurai Moe、Miyajima Nobuyoshi、Ohfuji Hiroaki、Katsura Tomoo、Yamamoto Takafumi
  • Journal Title: Science Advances Volume: 3
  • DOI: 10.1126/sciadv.1603024
  • Peer Reviewed / Open Access / Int'l Joint Research
• [Journal Article] Synthesis of boron-doped diamond and its application as a heating material in a multi-anvil high-pressure apparatus (2017)
  • Author(s): Longjian Xie, Akira Yoneda, Takashi Yoshino, Daisuke Yamazaki, Noriyoshi Tsujino, Yuji Higo, Yoshinori Tange, Tetsuo Irifune, Toru Shimei, Eiji Ito
  • Journal Title: Rev. Sci. Instrum. Volume: 88 Pages: 093904-093904
  • DOI: 10.1063/1.4993959
  • Peer Reviewed / Open Access / Int'l Joint Research
• [Presentation] Iron diffusion in e-iron (2020)
  • Author(s): D. Yamazaki, N. Sakamoto, H. Yurimoto
  • Organizer: JpGU 2020
  • Int'l Joint Research
• [Presentation] e鉄中の鉄の自己拡散 (2020)
  • Author(s): 山崎大輔・坂本直哉・圦本尚義
  • Organizer: 第61回高圧討論会
• [Presentation] Shear deformation on post-spinel (2019)
  • Author(s): D. Yamazaki, N. Tsujino, T. Yoshino, Y. Nishihara
  • Organizer: JpGU 2019
  • Int'l Joint Research
• [Presentation] 高圧実験に基づく下部マントルのレオロジー (2019)
  • Author(s): 山崎大輔
  • Organizer: 日本鉱物科学会2019年年会・総会
  • Invited
• [Presentation] ポストスピネルの剪断変形実験 (2019)
  • Author(s): 山崎大輔・辻野典秀・芳野極・西原遊
  • Organizer: 第60回高圧討論会
• [Presentation] Effect of silicon on viscosity of epsilon-iron (2018)
  • Author(s): Yamazaki, D
  • Organizer: JpGU
• [Presentation] ポストスピネルの剪断変形実験 (2018)
  • Author(s): 山崎大輔
  • Organizer: 第59回高圧討論会
• [Presentation] Pressure Generation in a Kawai-type Multianvil Apparatus Equipped with Sintered Diamond Anvils (2017)
  • Author(s): Yamazaki, D.
  • Organizer: AIRAPT26 Joint with ACHPR 8 & CHPC 19
  • Int'l Joint Research / Invited
• [Presentation] Pressure generation of 120 GPa in a Kawai-type apparatus and stability of bridgmanite (2017)
  • Author(s): Yamazaki, D.
  • Organizer: 地球惑星関連連合大会(JpGU)
• [Presentation] 六方晶鉄の変形実験：軽元素の影響 (2017)
  • Author(s): 山崎大輔
  • Organizer: 高圧討論会