Spatiotemporal distributions of mantle heterogeneity estimated from mid-ocean ridge basalts at Central Indian ridge

2017 Fiscal Year Final Research Report

• Project/Area Number: 15K05317
• Research Category: Grant-in-Aid for Scientific Research (C)
• Allocation Type: Multi-year Fund
• Section: 一般
• Research Field: Geology
• Research Institution: Senshu University
• Principal Investigator: SATO HIROSHI 専修大学, 経営学部, 教授 (50365847)
• 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)
• Co-Investigator(Renkei-kenkyūsha): SENDA Ryoko 九州大学, 比較社会文化研究院, 准教授 (50377991)
• Project Period (FY): 2015-04-01 – 2018-03-31
• Keywords: 中央海嶺玄武岩 / マントル不均質 / 中央インド洋海嶺

Outline of Final Research Achievements

Trace element compositions and isotope compositions were analyzed for mid-ocean ridge basalts from the southernmost segment of Central Indian Ridge to reveal actual spatiotemporal distributions of mantle heterogeneity. Our results show the correlation between trace element compositions (e.g., Nb/Zr) and Sr isotope ratio. Particularly mid-ocean ridge basalts collected far from the present spreading axis of Central Indian Ridge have depleted trace element compositions (e.g., low Nb/Zr) and high Sr isotope ratio. Nd isotope ratio has no correlation with both trace element compositions and Sr isotope ratio. We concluded that source mantles which generated older mid-ocean ridge basalts have lower Nb/Zr and higher Rb/Sr ratios at the southernmost segment of Central Indian Ridge.

Free Research Field

海洋岩石学