A HIMU-like component in Mariana Convergent Margin magma sources during initial arc rifting revealed by melt inclusions

Xiaohui Li; Osamu Ishizuka; Robert J Stern; Sanzhong Li; Zhiqing Lai; Ian Somerville; Yanhui Suo; Long Chen; Hongxia Yu

doi:10.1038/s41467-024-48308-y

A HIMU-like component in Mariana Convergent Margin magma sources during initial arc rifting revealed by melt inclusions

Nat Commun. 2024 May 14;15(1):4088. doi: 10.1038/s41467-024-48308-y.

Authors

Xiaohui Li^{1

2

3}, Osamu Ishizuka^{4

5}, Robert J Stern⁶, Sanzhong Li^{7

8}, Zhiqing Lai¹, Ian Somerville⁹, Yanhui Suo^{1

2}, Long Chen^{1

2}, Hongxia Yu¹⁰

Affiliations

¹ Frontiers Science Center for Deep Ocean Multispheres and Earth System, Key Lab of Submarine Geosciences and Prospecting Techniques, MOE and College of Marine Geosciences, Ocean University of China, Qingdao, 266100, China.
² Laboratory for Marine Mineral Resources, Qingdao Marine Science and Technology Center, Qingdao, 266237, China.
³ Key Laboratory of Marine Geology and Environment, Institute of Oceanology, Chinese Academy of Sciences, Qingdao, 266071, China.
⁴ Institute of Geology and Geoinformation, Geological Survey of Japan/AIST, Central 7, 1-1-1, Higashi, Tsukuba, Ibaraki, 305-8567, Japan.
⁵ Japan Agency for Marine-Earth Science and Technology, 2-15 Natsushima, Yokosuka, Kanagawa, 237-0061, Japan.
⁶ Department of Sustainable Earth Systems Science, University of Texas at Dallas, Richardson, TX, 75080, USA.
⁷ Frontiers Science Center for Deep Ocean Multispheres and Earth System, Key Lab of Submarine Geosciences and Prospecting Techniques, MOE and College of Marine Geosciences, Ocean University of China, Qingdao, 266100, China. sanzhong@ouc.edu.cn.
⁸ Laboratory for Marine Mineral Resources, Qingdao Marine Science and Technology Center, Qingdao, 266237, China. sanzhong@ouc.edu.cn.
⁹ UCD School of Earth Sciences, University College Dublin, Belfield, Dublin, 4, Ireland.
¹⁰ Guangxi Key Laboratory of Hidden Metallic Ore Deposits Exploration, Guilin University of Technology, Guilin, 541006, China.

Abstract

Compositions of island arc and back-arc basin basalts are often used to trace the recycling of subducted materials. However, the contribution of subducted components to the mantle source during initial arc rifting before back-arc basin spreading is not yet well constrained. The northernmost Mariana arc is ideal for studying this because the transition from rifting to back-arc spreading is happening here. Here we report major and trace element and Pb isotopic compositions of olivine-hosted melt inclusions from lavas erupted during initial rifting at 24°N (NSP-24) and compare them with those in active arc front at 21°N and mature back-arc basin at 18°N. NSP-24 high-K melt inclusions have highly radiogenic Pb compositions and are close to those of the HIMU end-member, suggesting the presence of this component in the magma source. The HIMU-like component may be stored in the over-riding plate and released into arc magma with rifting. HIMU-type seamounts may be subducted elsewhere beneath the Mariana arc, but obvious HIMU-type components appear only in the initial stages of arc rifting due to the low melting degree and being consumed during the process of back-arc spreading.

Abstract

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