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Xu R, Cai Y, Lambart S, Chen C, Zhang JB, Zhou MF, Liu J, Bai Z, Wu T, Huang F, Ruan T, Liu Y. Heavy boron isotopes in intraplate basalts reveal recycled carbonate in the mantle. SCIENCE ADVANCES 2025; 11:eads5104. [PMID: 40267202 PMCID: PMC12017311 DOI: 10.1126/sciadv.ads5104] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/21/2024] [Accepted: 03/18/2025] [Indexed: 04/25/2025]
Abstract
Recycling of surficial volatiles such as carbon into the mantle plays a fundamental role in modulating Earth's habitability. However, slab devolatilization during subduction could prevent carbon from entering the deep mantle. Boron isotopes are excellent tracers of recycled volatiles, but correlations between boron isotopes and mantle heterogeneity indicators are rarely observed, thereby casting doubt that substantial amounts of volatiles and boron can be recycled into the deep mantle. Here, we show that boron isotopes in two different types of primitive continental intraplate basalts correlate well with mantle heterogeneity indicators, indicating contributions of various subducted crustal components. A common high-δ11B component shared by both types of basalts is best explained as recycled subducted carbonate rather than serpentinite. Our findings demonstrate that subducted carbonate carries heavy B into Earth's deep mantle, and its recycling could account for the high-δ11B signatures observed in intraplate magmas and deeply sourced carbonatites.
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Affiliation(s)
- Rong Xu
- State Key Laboratory of Critical Mineral Research and Exploration, Institute of Geochemistry, Chinese Academy of Sciences, Guiyang 550081, China
| | - Yue Cai
- State Key Laboratory of Palaeobiology and Stratigraphy, Nanjing Institute of Geology and Palaeontology, Chinese Academy of Sciences, Nanjing 210008, China
| | - Sarah Lambart
- Geology and Geophysics, University of Utah, Salt Lake City, UT, USA
| | - Chunfei Chen
- State Key Laboratory of Geological Processes and Mineral Resources, School of Earth Sciences, China University of Geosciences, Wuhan 430074, China
| | - Jun-Bo Zhang
- YU-CUGW Joint Research Center on Deep Earth and Surface Dynamic Coupling, College of Resources and Environment, Yangtze University, Wuhan 430100, China
| | - Mei-Fu Zhou
- State Key Laboratory of Critical Mineral Research and Exploration, Institute of Geochemistry, Chinese Academy of Sciences, Guiyang 550081, China
| | - Jia Liu
- Key Laboratory of Geoscience Big Data and Deep Resource of Zhejiang Province, School of Earth Sciences, Zhejiang University, Hangzhou 310027, China
| | - Zhongjie Bai
- State Key Laboratory of Critical Mineral Research and Exploration, Institute of Geochemistry, Chinese Academy of Sciences, Guiyang 550081, China
| | - Tao Wu
- Ocean College, Zhejiang University, Zhoushan 316021, China
| | - Feng Huang
- State Key Laboratory of Geological Processes and Mineral Resources, School of Earth Science and Resources, China University of Geosciences, Beijing 100083, China
| | - Ting Ruan
- State Key Laboratory of Palaeobiology and Stratigraphy, Nanjing Institute of Geology and Palaeontology, Chinese Academy of Sciences, Nanjing 210008, China
| | - Yongsheng Liu
- State Key Laboratory of Geological Processes and Mineral Resources, School of Earth Sciences, China University of Geosciences, Wuhan 430074, China
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Keller DS, Lee CTA, Peck WH, Monteleone BD, Martin C, Vervoort JD, Bolge L. Mafic slab melt contributions to Proterozoic massif-type anorthosites. SCIENCE ADVANCES 2024; 10:eadn3976. [PMID: 39141730 PMCID: PMC11323888 DOI: 10.1126/sciadv.adn3976] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/08/2023] [Accepted: 07/09/2024] [Indexed: 08/16/2024]
Abstract
Massif-type anorthosites, enormous and enigmatic plagioclase-rich cumulate intrusions emplaced into Earth's crust, formed in large numbers only between 1 and 2 billion years ago. Conflicting hypotheses for massif-type anorthosite formation, including melting of upwelling mantle, lower crustal melting, and arc magmatism above subduction zones, have stymied consensus on what parental magmas crystallized the anorthosites and why the rocks are temporally restricted. Using B, O, Nd, and Sr isotope analyses, bulk chemistry, and petrogenetic modeling, we demonstrate that the magmas parental to the Marcy and Morin anorthosites, classic examples from North America's Grenville orogen, require large input from mafic melts derived from slab-top altered oceanic crust. The anorthosites also record B isotopic signatures corresponding to other slab lithologies such as subducted abyssal serpentinite. We propose that anorthosite massifs formed underneath convergent continental margins wherein a subducted or subducting slab melted extensively and link massif-type anorthosite formation to Earth's thermal and tectonic evolution.
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Affiliation(s)
- Duncan S. Keller
- Department of Earth, Environmental and Planetary Sciences, Rice University, Houston, TX 77005, USA
| | - Cin-Ty A. Lee
- Department of Earth, Environmental and Planetary Sciences, Rice University, Houston, TX 77005, USA
| | - William H. Peck
- Department of Earth and Environmental Geosciences, Colgate University, Hamilton, NY 13346, USA
| | - Brian D. Monteleone
- Department of Geology and Geophysics, Woods Hole Oceanographic Institution, Woods Hole, MA 02543, USA
| | - Céline Martin
- Department of Earth and Planetary Sciences, American Museum of Natural History, New York, NY 10024, USA
| | - Jeffrey D. Vervoort
- School of the Environment, Washington State University, Pullman, WA 99164, USA
| | - Louise Bolge
- Lamont-Doherty Earth Observatory, Columbia University, Palisades, NY 10964, USA
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