MOWALL: Moho Observation along transform fault WALLs

• Project/Area Number: 18H01303
• Research Category: Grant-in-Aid for Scientific Research (B)
• Allocation Type: Single-year Grants
• Section: 一般
• Review Section: Basic Section 17040:Solid earth sciences-related
• Research Institution: The University of Tokyo
• Principal Investigator: Okino Kyoko 東京大学, 大気海洋研究所, 教授 (30313191)
• Co-Investigator(Kenkyū-buntansha): 町田 嗣樹 千葉工業大学, 次世代海洋資源研究センター, 上席研究員 (40444062) ; 中村 謙太郎 東京大学, 大学院工学系研究科(工学部), 准教授 (40512083) ; 森下 知晃 金沢大学, 地球社会基盤学系, 教授 (80334746)
• Project Period (FY): 2018-04-01 – 2023-03-31
• Project Status: Completed (Fiscal Year 2022)
• Budget Amount: ¥17,160,000 (Direct Cost: ¥13,200,000、Indirect Cost: ¥3,960,000); Fiscal Year 2021: ¥2,210,000 (Direct Cost: ¥1,700,000、Indirect Cost: ¥510,000); Fiscal Year 2020: ¥3,120,000 (Direct Cost: ¥2,400,000、Indirect Cost: ¥720,000); Fiscal Year 2019: ¥6,110,000 (Direct Cost: ¥4,700,000、Indirect Cost: ¥1,410,000); Fiscal Year 2018: ¥3,900,000 (Direct Cost: ¥3,000,000、Indirect Cost: ¥900,000)
• Keywords: 海洋リソスフィア / 海洋地殻 / 中央海嶺 / 背弧拡大 / マントル / トランスフォーム断層 / マントル不均質 / 背弧海盆 / 中央海嶺プロセス / かんらん岩 / 背弧拡大系

Outline of Final Research Achievements

Geophysical observations and rock sampling were carried out along a flow line (plate motion direction) from the ridge axis to the past in order to clarify whether there are multi-million-year-scale temporal variations in the oceanic crustal production process, and if so, what factors are responsible for these variations. We found that crustal thickness varies on a 3-5 million year scale at the Central Indian Ocean Ridge and Southern Ocean, that mantle heterogeneity exists on a similar spatial scale, and that a decrease in spreading rate and melt supply occurs at the end of the back arc spreading system.

Academic Significance and Societal Importance of the Research Achievements

海洋地殻は地球表層の7割を占める構造であり，中央海嶺や背弧のシステムの包括的な理解はプレートテクトニクスや地球のダイナミクス，さらに地球の進化において重要である．本研究では，これまで場所による多様性（空間変化）を中心に研究が進んできた中央海嶺研究に，時間変化という視点を入れた点で当該分野に貢献している．

Research Products

• [Int'l Joint Research] The Department for Coastal Shelf(モーリシャス)
• [Int'l Joint Research] THE DEPARTMENT FOR CONTINENTAL SHELF(モーリシャス)
• [Int'l Joint Research] Dept for continental shelf, Mauritius(その他の国・地域)
• [Int'l Joint Research] Laboratoire de Geologie - CNRS UMR(フランス)
• [Journal Article] Secular Variations in Provenance of Sedimentary Components in the Western North Pacific Ocean Constrained by Sr Isotopic Features of Deep‐Sea Sediments (2022)
  • Author(s): Tanaka Erika、Yasukawa Kazutaka、Nakamura Kentaro、Ohta Junichiro、Miyazaki Takashi、Vaglarov Bogdan Stefanov、Machida Shiki、Fujinaga Koichiro、Iwamori Hikaru、Kato Yasuhiro
  • Journal Title: Geochemistry, Geophysics, Geosystems Volume: 23 Issue: 1
  • DOI: 10.1029/2021gc009729
  • Peer Reviewed / Open Access / Int'l Joint Research
• [Journal Article] Validation of Trace Element Analysis of Geological Materials by Single-Pulse Laser Ablation-Inductively Coupled Plasma-Mass Spectrometry (LA-ICP-MS) (2022)
  • Author(s): Sagawa Takuya、Tamura Akihiro、Okino Kyoko、Morishita Tomoaki
  • Journal Title: Analytical Letters Volume: 55 Issue: 18 Pages: 2886-2896
  • DOI: 10.1080/00032719.2022.2077356
  • Peer Reviewed / Open Access
• [Journal Article] Determination of whole-rock trace-element compositions of siliceous rocks using MgO-diluted fused glass and LA–ICP–MS (2022)
  • Author(s): Tamura Akihiro、Sagawa Takuya、Okino Kyoko、Morishita Tomoaki
  • Journal Title: GEOCHEMICAL JOURNAL Volume: 56 Issue: 6 Pages: 231-239
  • DOI: 10.2343/geochemj.GJ22020
  • ISSN: 0016-7002, 1880-5973
  • Peer Reviewed / Open Access
• [Journal Article] Crucial Scientific Issues in Earth Science Revealed Only by Mantle Drilling: Understanding the Current State of the Oceanic Plates of a Life-bearing Planet (2021)
  • Author(s): 森下知晃・藤江剛・平内健一・片山郁夫・纐纈佑衣・黒田潤一郎・岡本敦・小野重明・道林克禎諸野祐樹・山本伸次
  • Journal Title: Journal of Geography (Chigaku Zasshi) Volume: 130 Issue: 4 Pages: 483-506
  • DOI: 10.5026/jgeography.130.483
  • NAID: 130008091267
  • ISSN: 0022-135X, 1884-0884
  • Year and Date: 2021-08-25
  • Peer Reviewed / Open Access
• [Journal Article] Alteration processes recorded by back-arc mantle peridotites from oceanic core complexes, Shikoku Basin, Philippine Sea (2021)
  • Author(s): Hirauchi, K., Segawa, I., Kouketsu, Y., Harigane, Y., Ohara, Y., Snow, J., Sen, A., Fujii, M., Okino, K.
  • Journal Title: Island Arc Volume: 30 Issue: 1 Pages: 1-13
  • DOI: 10.1111/iar.12419
  • Peer Reviewed / Int'l Joint Research
• [Journal Article] Geochemical characteristics of back-arc basin lower crust and upper mantle at final spreading stage of Shikoku Basin: an example of Mado Megamullion (2021)
  • Author(s): Akizawa, N., Ohara, Y., Okino, K., Ishizuka, O., Yamashita, H., Machida, S., Sanflippo, A., Basch, V., Snow, J.E., Sen, A., Hirauchi, K., Michibayashi, K., Harigane, Y., Fujii, M., Asanuma, H., Hirata, T.
  • Journal Title: Progress in Earth and Planetary Science Volume: 8 Issue: 1 Pages: 65-65
  • DOI: 10.1186/s40645-021-00454-3
  • Peer Reviewed / Open Access / Int'l Joint Research
• [Journal Article] A Paleogene magmatic overprint on Cretaceous seamounts of the western Pacific (2021)
  • Author(s): Hirano Naoto、Sumino Hirochika、Morishita Taisei、Machida Shiki、Kawano Takaomi、Yasukawa Kazutaka、Hirata Takafumi、Kato Yasuhiro、Ishii Teruaki
  • Journal Title: Island Arc Volume: 30 Issue: 1
  • DOI: 10.1111/iar.12386
  • Peer Reviewed / Open Access
• [Journal Article] Magma‐Mush Interactions in the Lower Oceanic Crust: Insights From Atlantis Bank Layered Series (Southwest Indian Ridge) (2021)
  • Author(s): Boulanger M.、France L.、Ferrando C.、Ildefonse B.、Ghosh B.、Sanfilippo A.、Liu C.‐Z.、Morishita T.、Koepke J.、Bruguier O.
  • Journal Title: Journal of Geophysical Research: Solid Earth Volume: 126 Issue: 9
  • DOI: 10.1029/2021jb022331
  • Peer Reviewed / Int'l Joint Research
• [Journal Article] Rapid coupling between solid earth and ice volume during the Quaternary (2021)
  • Author(s): Kuwahara Yusuke、Yasukawa Kazutaka、Fujinaga Koichiro、Nozaki Tatsuo、Ohta Junichiro、Sato Honami、Kimura Jun-Ichi、Nakamura Kentaro、Yokoyama Yusuke、Kato Yasuhiro
  • Journal Title: Scientific Reports Volume: 11 Issue: 1 Pages: 5695-5695
  • DOI: 10.1038/s41598-021-84448-7
  • NAID: 120007028957
  • Peer Reviewed / Open Access / Int'l Joint Research
• [Journal Article] Crustal Accretion in a Slow Spreading Back‐Arc Basin: Insights From the Mado Megamullion Oceanic Core Complex in the Shikoku Basin (2020)
  • Author(s): Basch V.、Sanfilippo A.、Sani C.、Ohara Y.、Snow J.、Ishizuka O.、Harigane Y.、Michibayashi K.、Sen A.、Akizawa N.、Okino K.、Fujii M.、Yamashita H.
  • Journal Title: Geochemistry, Geophysics, Geosystems Volume: 21 Issue: 11 Pages: 1-14
  • DOI: 10.1029/2020gc009199
  • Peer Reviewed / Open Access / Int'l Joint Research
• [Journal Article] Melt-rock interaction in the subarc mantle: records from the plagioclase peridotites of the southern Palawan Ophiolite, Philippines (2020)
  • Author(s): Labis Florence Annette C.、Payot Betchaida D.、Valera Gabriel Theophilus V.、Pasco Julius A.、Dycoco Jesley Mei A.、Tamura Akihiro、Morishita Tomoaki、Arai Shoji
  • Journal Title: International Geology Review Volume: － Issue: 9 Pages: 1-23
  • DOI: 10.1080/00206814.2020.1746930
  • Peer Reviewed / Int'l Joint Research
• [Journal Article] Compositional heterogeneity and melt transport in mantle beneath Mid-Atlantic Ridge constrained by peridotite, dunite, and wehrlite from Atlantis Massif (2020)
  • Author(s): Akizawa Norikatsu、Freh-Green Gretchen L.、Tamura Akihiro、Tamura Chiori、Morishita Tomoaki
  • Journal Title: Lithos Volume: 354-355 Pages: 105364-105364
  • DOI: 10.1016/j.lithos.2019.105364
  • Peer Reviewed / Int'l Joint Research
• [Journal Article] Melt-fluid infiltration along detachment shear zones in oceanic core complexes: Insights from amphiboles in gabbro mylonites from the Godzilla Megamullion, Parece Vela Basin, the Philippine Sea (2019)
  • Author(s): Harigane Yumiko、Okamoto Atsushi、Morishita Tomoaki、Snow Jonathan E.、Tamura Akihiro、Yamashita Hiroyuki、Michibayashi Katsuyoshi、Ohara Yasuhiko、Arai Shoji
  • Journal Title: Lithos Volume: 344-345 Pages: 217-231
  • DOI: 10.1016/j.lithos.2019.06.019
  • Peer Reviewed / Int'l Joint Research
• [Journal Article] Occurrence of Felsic Rocks in Oceanic Gabbros from IODP Hole U1473A: Implications for Evolved Melt Migration in the Lower Oceanic Crust (2018)
  • Author(s): Nguyen Du、Morishita Tomoaki、Soda Yusuke、Tamura Akihiro、Ghosh Biswajit、Harigane Yumiko、France Lyd?ric、Liu Chuanzhou、Natland James、Sanfilippo Alessio、MacLeod Christopher、Blum Peter、Dick Henry
  • Journal Title: Minerals Volume: 8 Issue: 12 Pages: 583-583
  • DOI: 10.3390/min8120583
  • Peer Reviewed / Open Access / Int'l Joint Research
• [Journal Article] The uppermost mantle section below a remnant proto-Philippine Sea island arc: Insights from the peridotite fragments from the Daito Ridge (2018)
  • Author(s): Morishita Tomoaki、Tani Ken-Ichiro、Soda Yusuke、Tamura Akihiro、Mizukami Tomoyuki、Ghosh Biswajit
  • Journal Title: American Mineralogist Volume: 103 Issue: 7 Pages: 1151-1160
  • DOI: 10.2138/am-2018-6030
  • Peer Reviewed / Int'l Joint Research
• [Journal Article] Near-seafloor magnetic mapping of off-axis lava flows near the Kairei and Yokoniwa hydrothermal vent fields in the Central Indian Ridge (2018)
  • Author(s): Fujii Masakazu、Okino Kyoko
  • Journal Title: Earth, Planets and Space Volume: 70 Issue: 1 Pages: 1-17
  • DOI: 10.1186/s40623-018-0959-5
  • Peer Reviewed / Open Access
• [Journal Article] Direct ascent to the surface of asthenospheric magma in a region of convex lithospheric flexure (2017)
  • Author(s): Sato Yuki、Hirano Naoto、Machida Shiki、Yamamoto Junji、Nakanishi Masao、Ishii Teruaki、Taki Arashi、Yasukawa Kazutaka、Kato Yasuhiro
  • Journal Title: International Geology Review Volume: - Issue: 10 Pages: 1-13
  • DOI: 10.1080/00206814.2017.1379912
  • Peer Reviewed
• [Presentation] Tectono-magmatic origin of the Conrad Rise: Key to understanding the development of the southwestern Indian Ocean during the Late Cretaceous (2022)
  • Author(s): 佐藤暢，町田嗣樹，仙田量子，石塚治，Meyzen Christine，Bizimis Michael，佐藤太一，藤井昌和，野木義史
  • Organizer: 日本地球惑星科学連合2022大会
• [Presentation] Water content in olivine at the Paleo-Crust/Mantle boundary recovered by the ICDP Oman Drilling project. (2022)
  • Author(s): Morishita, T., Aminud, M.A., Shimizu, K., Ushikubo, T., Senda, R., Yoshikawa, M., Itano, K., TamuraWater content in olivine at the Paleo-Crust/Mantle boundary recovered by the ICDP Oman Drilling project.
  • Organizer: 日本地球惑星科学連合2022大会
  • Invited
• [Presentation] Melting and evolution of peridotites at the Mado Megamullion, and oceanic core complex in the Shikoku back-arc basin (2021)
  • Author(s): Sen, A., J.E. Snow, (中略), K. Okino and N. Akizawa
  • Organizer: AGU Fall Meeting
  • Int'l Joint Research
• [Presentation] 海洋地殻生産の時間変動を追う (2021)
  • Author(s): 沖野郷子
  • Organizer: 京都大学防災研究所70周年地震・火山グループ研究会
  • Invited
• [Presentation] 南大洋バルカントランスフォーム断層に沿った海洋地殻生産の時間変動：白鳳丸KH-19-6 (2021)
  • Author(s): 沖野郷子，谷健一郎，石塚治，高下裕章，周錦煜
  • Organizer: 日本地球惑星科学連合2021大会
• [Presentation] Mado Megamullion: a potential new target for IODP drilling to understand backarc basin lithosphere (2021)
  • Author(s): 小原泰彦，藤井昌和, (中略), 町田嗣樹, (中略), 沖野郷子
  • Organizer: 日本地球惑星科学連合2021大会
• [Presentation] 南東インド洋海嶺での深海磁気観測：29-33百万歳の海底の記録 (2021)
  • Author(s): 藤井昌和，沖野郷子，田村千織
  • Organizer: 日本地球惑星科学連合2021大会
• [Presentation] Development of Research Instruments for unexplored frontiers in the Southern Ocean and Atnarctica (2021)
  • Author(s): 野木義史(中略)，沖野郷子，ほか
  • Organizer: 日本地球惑星科学連合2021大会
• [Presentation] 西太平洋プチスポット火山から探る太平洋プレート最古部の地殻・マントル (2021)
  • Author(s): 三國和音，平野直人，秋澤紀克，町田嗣樹
  • Organizer: 日本地球惑星科学連合2021大会2021
• [Presentation] Geochemical variation across the segment in the southernmost segment of the Central Indian Ridge (2020)
  • Author(s): 佐藤暢，町田嗣樹，仙田量子
  • Organizer: JpGU-AGU2020
• [Presentation] MOWALL: 長大トランスフォーム断層に沿って海洋地殻生産の時空間変動を追う (2020)
  • Author(s): 沖野郷子，森下知晃，町田嗣樹，中村謙太郎，小原泰彦，谷健一郎，石塚治
  • Organizer: JpGU-AGU2020
• [Presentation] Oceanic lower crust and uppermost mantle of the Shikoku Basin: insights from expeditions to Mado Megamullion (2020)
  • Author(s): 小原泰彦，沖野郷子，秋澤紀克，藤井昌和，針金由美子，平内健一，石塚治，町田嗣樹，道林克禎，Alessio Sanifilippo, Camilla Sani, Jonathan E. Snow, 谷健一郎，山下浩之
  • Organizer: JpGU-AGU2020
• [Presentation] Geophysics in the R/V Hakuho-maru 2019-2020 expeditions around the world, 30th anniversary (2020)
  • Author(s): 藤井昌和，高下裕章，Zhou Jinyu, 佐藤暢，沖野郷子，田村千織，井上耕輔
  • Organizer: JpGU-AGU2020
• [Presentation] Temporal variation of crustal accretion along the Vulcan Transform, the Southern Ocean (2020)
  • Author(s): Okino, K., K. Tani, O. Ishizuka, H. Koge, J. Zhou
  • Organizer: AGU 2020 Fall Meeting
  • Int'l Joint Research
• [Presentation] 中央海嶺プロセスの短期変動の観測 (2020)
  • Author(s): 藤井昌和，野木義史，沖野郷子，田村千織，山崎俊嗣，佐藤暢，高下裕章，喜岡新
  • Organizer: 海と地球のシンポジウム
• [Presentation] 四国海盆海洋コアコンプレックスから明らかにする背弧海盆海洋地殻 (2020)
  • Author(s): 小原泰彦，沖野郷子，秋澤紀克，藤井昌和，針金由美子，平内健一，石塚治，町田嗣樹，道林克禎，Alessio Sanifilippo, Camilla Sani, Jonathan E. Snow, 谷健一郎，山下浩之
  • Organizer: 海と地球のシンポジウム
• [Presentation] 背弧海盆におけるマグマ活動：マドメガムリオン （四国海盆）の例 (2020)
  • Author(s): 秋澤紀克, 小原泰彦，沖野郷子, 石塚治，山下浩之
  • Organizer: 地球化学会
• [Presentation] 四国海盆海洋コアコンプレックスの形成 (2019)
  • Author(s): 沖野郷子，小原泰彦，藤井昌和，羽入朋子
  • Organizer: InterRidge-Japanシンポジウム
• [Presentation] Spatial variation of petrological and geochemical characteristics of mantle peridotites in Mado Megamullion, Shikoku Basin (2019)
  • Author(s): 秋澤紀克，町田嗣樹，沖野郷子，小原泰彦
  • Organizer: JpGU2019
• [Presentation] Submersible magnetics reveals relationship between off-axis volcanism and hydrothermal systems of the Kairei and Yokoniwa fields at the Central Indian Ridge (2019)
  • Author(s): 藤井昌和，沖野郷子
  • Organizer: JpGU2019
• [Presentation] 四国海盆海洋コアコンプレックスの発達：背弧拡大が止まるとき (2019)
  • Author(s): 沖野郷子，小原泰彦，藤井昌和，羽入朋子
  • Organizer: JpGU2019
• [Presentation] Introducing an oceanic core complex in the Shikoku Basin: Mado Megamullion (2019)
  • Author(s): 小原泰彦,沖野郷子, 秋澤紀克, 藤井昌和,針金由美子，平野直人，平内健一郎，石塚治，町田嗣樹，道林克禎，Alessio Sanifilippo, Jonathan Snow, 山下浩之
  • Organizer: JpGU2019
• [Presentation] MOWALL: Moho Observation along transforms fault WALLs (2018)
  • Author(s): Okino, K.
  • Organizer: InterRidge Working Group Oceanic Transform Faults FIRST WORKSHOP
  • Int'l Joint Research
• [Presentation] 四国海盆海洋コアコンプレックスの形成-YK18-07, KH-18-02 (2018)
  • Author(s): 沖野郷子，小原泰彦，道林克禎，町田嗣樹，針金由美子，秋澤紀克，藤井昌和，Nguen Khac Du, 柿畑優季，安藤宏太，周錦煜，羽入朋子
  • Organizer: ブルーアースサイエンス・テク2019
• [Presentation] A new tectonic window into the backarc basin lower oceanic crust and upper mantle: Mado Megamullion in the Shikoku Basin (2018)
  • Author(s): Ohara, Y., K. Okino, N. Akizawa, M. Fujii, Y. Harigane, N. Hirano, K.-I. Hirauchi, S. Machida, K. Michibayashi, A. Sanfilippo, J. E. Snow, H. Yamashita
  • Organizer: AGU Fall Meeting
  • Int'l Joint Research
• [Presentation] Expedition for petit-spot volcanism on the oldest Pacific Plate: the preliminary report of cruise YK18-08, R/V Yokosuka (2018)
  • Author(s): Machida, S., J. Kaneko, N. Hirano, Shipboard Scientific Party YK18-08
  • Organizer: AGU Fall Meeting
  • Int'l Joint Research
• [Presentation] Insights on the formation and modification of Oceanic Plate by Hard rock drillings: Why, Where, How and When? (2018)
  • Author(s): T. Morishita
  • Organizer: The 2nd Asia-Pacific Workshop on Lithosphere and Mantle Dynamics
  • Int'l Joint Research / Invited
• [Remarks] MOWALL
  • URL: http://ofgs.aori.u-tokyo.ac.jp/tilde/okino/mowall/