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Liu S, Lu W, Zhang X, Song J, Lü J, Liu X, Wang Y, Chen C, Ma Y. A viable mechanism to form boron-bearing diamonds in deep Earth. Sci Bull (Beijing) 2023:S2095-9273(23)00381-X. [PMID: 37353437 DOI: 10.1016/j.scib.2023.06.011] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/15/2023] [Revised: 05/22/2023] [Accepted: 05/24/2023] [Indexed: 06/25/2023]
Abstract
Boron is considered extremely depleted inside Earth's mantle. It is therefore a great challenge to elucidate the prevalence of boron impurity seen in sublithospheric diamonds, especially in identifying the boron source and the mechanism for its incorporation into these enigmatic diamonds. Here, we unveil a pathway for the crystallization of boron-bearing diamonds via redox reactions of carbonates and borides at pressure-temperature conditions relevant to the Earth's lower mantle. We present computational results along with pertinent experimental evidence for a genesis of boron-bearing diamonds via the redox reaction of CaCO3 and FeB at 22.5 GPa and 2100 K, corresponding to the geological conditions at the top of the lower mantle. The present findings offer a viable mechanism for the formation of boron-bearing diamonds deep inside the Earth's mantle.
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Affiliation(s)
- Siyu Liu
- Key Laboratory of Material Simulation Methods and Software of Ministry of Education, College of Physics, Jilin University, Changchun 130012, China; State Key Laboratory of Superhard Materials, College of Physics, Jilin University, Changchun 130012, China
| | - Wencheng Lu
- Key Laboratory of Material Simulation Methods and Software of Ministry of Education, College of Physics, Jilin University, Changchun 130012, China; State Key Laboratory of Superhard Materials, College of Physics, Jilin University, Changchun 130012, China
| | - Xiaoran Zhang
- Laboratory of High Pressure Physics and Material Science, School of Physics and Physical Engineering, Qufu Normal University, Qufu 273100, China
| | - Jingyan Song
- Laboratory of High Pressure Physics and Material Science, School of Physics and Physical Engineering, Qufu Normal University, Qufu 273100, China
| | - Jian Lü
- Key Laboratory of Material Simulation Methods and Software of Ministry of Education, College of Physics, Jilin University, Changchun 130012, China; State Key Laboratory of Superhard Materials, College of Physics, Jilin University, Changchun 130012, China
| | - Xiaobing Liu
- Laboratory of High Pressure Physics and Material Science, School of Physics and Physical Engineering, Qufu Normal University, Qufu 273100, China.
| | - Yanchao Wang
- Key Laboratory of Material Simulation Methods and Software of Ministry of Education, College of Physics, Jilin University, Changchun 130012, China; State Key Laboratory of Superhard Materials, College of Physics, Jilin University, Changchun 130012, China.
| | - Changfeng Chen
- Department of Physics and Astronomy, University of Nevada, Las Vegas, NV 89154, USA.
| | - Yanming Ma
- Key Laboratory of Material Simulation Methods and Software of Ministry of Education, College of Physics, Jilin University, Changchun 130012, China; State Key Laboratory of Superhard Materials, College of Physics, Jilin University, Changchun 130012, China; International Center of Future Science, Jilin University, Changchun 130012, China.
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Li HY, Li X, Ryan JG, Zhang C, Xu YG. Boron isotopes in boninites document rapid changes in slab inputs during subduction initiation. Nat Commun 2022; 13:993. [PMID: 35194052 PMCID: PMC8863828 DOI: 10.1038/s41467-022-28637-6] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/10/2019] [Accepted: 02/02/2022] [Indexed: 11/22/2022] Open
Abstract
How subduction-related magmatism starts at convergent plate margins is still poorly understood. Here we show that boron isotope variations in early-formed boninites from the Izu-Bonin arc, combined with radiogenic isotopes and elemental ratios document rapid (~0.5 to 1 Myr) changes in the sources and makeup of slab inputs as subduction begins. Heterogeneous hornblende-granulite facies melts from ocean crust gabbros ± basalts fluxed early melting to generate low silica boninites. Hydrous fluids from slab sediments and basalts later fluxed the low silica boninites mantle source to produce high silica boninites. Our results suggest that initially the uppermost parts of the slab were accreted near the nascent trench, perhaps related to early low-angle subduction. The rapid changes in slab inputs recorded in the boninites entail a steepening subduction angle and cooling of the plate interface, allowing for subduction of slab sediment and basalt, and generating hydrous fluids at lower slab temperatures. The geochemical record of subduction initiation is still not well understood, despite >50 years of study. Here, the authors use boron isotopes in Izu-Bonin boninites to document rapid changes in slab inputs to melting at the start of subduction, related to the steepening and cooling of the downgoing Pacific plate.
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Affiliation(s)
- Hong-Yan Li
- State Key Laboratory of Isotope Geochemistry, Guangzhou Institute of Geochemistry, Chinese Academy of Sciences, Guangzhou, 510640, China. .,CAS Center for Excellence in Deep Earth Science, Guangzhou, 510640, China. .,Southern Marine Science and Engineering Guangdong Laboratory (Guangzhou), Guangzhou, 511458, China.
| | - Xiang Li
- State Key Laboratory of Isotope Geochemistry, Guangzhou Institute of Geochemistry, Chinese Academy of Sciences, Guangzhou, 510640, China. .,University of Chinese Academy of Sciences, Beijing, 100049, China.
| | - Jeffrey G Ryan
- School of Geosciences, University of South Florida, Tampa, FL, 33620, USA.
| | - Chao Zhang
- State Key Laboratory of Continental Dynamics, Department of Geology, Northwest University, Xi'an, 710069, China
| | - Yi-Gang Xu
- State Key Laboratory of Isotope Geochemistry, Guangzhou Institute of Geochemistry, Chinese Academy of Sciences, Guangzhou, 510640, China.,CAS Center for Excellence in Deep Earth Science, Guangzhou, 510640, China.,Southern Marine Science and Engineering Guangdong Laboratory (Guangzhou), Guangzhou, 511458, China
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3
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Zhang Y, Gazel E, Gaetani GA, Klein F. Serpentinite-derived slab fluids control the oxidation state of the subarc mantle. SCIENCE ADVANCES 2021; 7:eabj2515. [PMID: 34826248 PMCID: PMC8626075 DOI: 10.1126/sciadv.abj2515] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 04/30/2021] [Accepted: 10/07/2021] [Indexed: 06/13/2023]
Abstract
Recent geochemical evidence confirms the oxidized nature of arc magmas, but the underlying processes that regulate the redox state of the subarc mantle remain yet to be determined. We established a link between deep subduction-related fluids derived from dehydration of serpentinite ± altered oceanic crust (AOC) using B isotopes and B/Nb as fluid proxies, and the oxidized nature of arc magmas as indicated by Cu enrichment during magma evolution and V/Yb. Our results suggest that arc magmas derived from source regions influenced by a greater serpentinite (±AOC) fluid component record higher oxygen fugacity. The incorporation of this component into the subarc mantle is controlled by the subduction system’s thermodynamic conditions and geometry. Our results suggest that the redox state of the subarc mantle is not homogeneous globally: Primitive arc magmas associated with flat, warm subduction are less oxidized overall than those generated in steep, cold subduction zones.
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Affiliation(s)
- Yuxiang Zhang
- Key Laboratory of Marine Geology and Environment, Institute of Oceanology, Chinese Academy of Sciences, Qingdao, Shandong, China
- Laboratory for Marine Mineral Resources, Qingdao Pilot National Laboratory for Marine Science and Technology, Qingdao, Shandong, China
- Center for Ocean Mega-Science, Chinese Academy of Sciences, Qingdao, Shandong, China
| | - Esteban Gazel
- Department of Earth and Atmospheric Sciences, Cornell University, Ithaca, NY, USA
| | - Glenn A. Gaetani
- Department of Geology and Geophysics, Woods Hole Oceanographic Institution, Woods Hole, MA, USA
| | - Frieder Klein
- Department of Marine Chemistry and Geochemistry, Woods Hole Oceanographic Institution, Woods Hole, MA, USA
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4
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Li HY, Zhao RP, Li J, Tamura Y, Spencer C, Stern RJ, Ryan JG, Xu YG. Molybdenum isotopes unmask slab dehydration and melting beneath the Mariana arc. Nat Commun 2021; 12:6015. [PMID: 34650082 PMCID: PMC8517010 DOI: 10.1038/s41467-021-26322-8] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/21/2021] [Accepted: 09/23/2021] [Indexed: 11/09/2022] Open
Abstract
How serpentinites in the forearc mantle and subducted lithosphere become involved in enriching the subarc mantle source of arc magmas is controversial. Here we report molybdenum isotopes for primitive submarine lavas and serpentinites from active volcanoes and serpentinite mud volcanoes in the Mariana arc. These data, in combination with radiogenic isotopes and elemental ratios, allow development of a model whereby shallow, partially serpentinized and subducted forearc mantle transfers fluid and melt from the subducted slab into the subarc mantle. These entrained forearc mantle fragments are further metasomatized by slab fluids/melts derived from the dehydration of serpentinites in the subducted lithospheric slab. Multistage breakdown of serpentinites in the subduction channel ultimately releases fluids/melts that trigger Mariana volcanic front volcanism. Serpentinites dragged down from the forearc mantle are likely exhausted at >200 km depth, after which slab-derived serpentinites are responsible for generating slab melts. How the subducted oceanic lithosphere provides fluids and melts to flux the subarc mantle source of arc magmas is controversial. Here the authors use Mo and other isotopes to show serpentinites formed in both the forearc mantle and the subducted lithosphere contribute to generating arc magmas.
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Affiliation(s)
- Hong-Yan Li
- State Key Laboratory of Isotope Geochemistry, Guangzhou Institute of Geochemistry, Chinese Academy of Sciences, Guangzhou, 510640, China. .,CAS Center for Excellence in Deep Earth Science, Guangzhou, 510640, China. .,Southern Marine Science and Engineering Guangdong Laboratory (Guangzhou), Guangzhou, 511458, China.
| | - Rui-Peng Zhao
- State Key Laboratory of Isotope Geochemistry, Guangzhou Institute of Geochemistry, Chinese Academy of Sciences, Guangzhou, 510640, China.,University of Chinese Academy of Sciences, Beijing, 100049, China
| | - Jie Li
- State Key Laboratory of Isotope Geochemistry, Guangzhou Institute of Geochemistry, Chinese Academy of Sciences, Guangzhou, 510640, China.,CAS Center for Excellence in Deep Earth Science, Guangzhou, 510640, China
| | - Yoshihiko Tamura
- Research Institute for Marine Geodynamics (IMG), Japan Agency for Marine-Earth Science and Technology (JAMSTEC), Yokosuka, 237-0061, Japan
| | - Christopher Spencer
- Department of Geological Sciences and Geological Engineering, Queen's University, Kingston, ON, K7L 3N6, Canada
| | - Robert J Stern
- Department of Geoscience, University of Texas at Dallas, Richardson, TX, 75080, USA
| | - Jeffrey G Ryan
- School of Geosciences, University of South Florida, Tampa, FL, 33620, USA
| | - Yi-Gang Xu
- State Key Laboratory of Isotope Geochemistry, Guangzhou Institute of Geochemistry, Chinese Academy of Sciences, Guangzhou, 510640, China.,CAS Center for Excellence in Deep Earth Science, Guangzhou, 510640, China.,Southern Marine Science and Engineering Guangdong Laboratory (Guangzhou), Guangzhou, 511458, China
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5
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Cooper GF, Macpherson CG, Blundy JD, Maunder B, Allen RW, Goes S, Collier JS, Bie L, Harmon N, Hicks SP, Iveson AA, Prytulak J, Rietbrock A, Rychert CA, Davidson JP. Variable water input controls evolution of the Lesser Antilles volcanic arc. Nature 2020; 582:525-529. [PMID: 32581382 DOI: 10.1038/s41586-020-2407-5] [Citation(s) in RCA: 39] [Impact Index Per Article: 9.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/14/2019] [Accepted: 03/26/2020] [Indexed: 11/09/2022]
Abstract
Oceanic lithosphere carries volatiles, notably water, into the mantle through subduction at convergent plate boundaries. This subducted water exercises control on the production of magma, earthquakes, formation of continental crust and mineral resources. Identifying different potential fluid sources (sediments, crust and mantle lithosphere) and tracing fluids from their release to the surface has proved challenging1. Atlantic subduction zones are a valuable endmember when studying this deep water cycle because hydration in Atlantic lithosphere, produced by slow spreading, is expected to be highly non-uniform2. Here, as part of a multi-disciplinary project in the Lesser Antilles volcanic arc3, we studied boron trace element and isotopic fingerprints of melt inclusions. These reveal that serpentine-that is, hydrated mantle rather than crust or sediments-is a dominant supplier of subducted water to the central arc. This serpentine is most likely to reside in a set of major fracture zones subducted beneath the central arc over approximately the past ten million years. The current dehydration of these fracture zones coincides with the current locations of the highest rates of earthquakes and prominent low shear velocities, whereas the preceding history of dehydration is consistent with the locations of higher volcanic productivity and thicker arc crust. These combined geochemical and geophysical data indicate that the structure and hydration of the subducted plate are directly connected to the evolution of the arc and its associated seismic and volcanic hazards.
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Affiliation(s)
- George F Cooper
- School of Earth Sciences, University of Bristol, Bristol, UK. .,School of Earth and Ocean Sciences, Cardiff University, Cardiff, UK.
| | | | - Jon D Blundy
- School of Earth Sciences, University of Bristol, Bristol, UK
| | - Benjamin Maunder
- Department of Earth Science and Engineering, Imperial College London, London, UK
| | - Robert W Allen
- Department of Earth Science and Engineering, Imperial College London, London, UK
| | - Saskia Goes
- Department of Earth Science and Engineering, Imperial College London, London, UK
| | - Jenny S Collier
- Department of Earth Science and Engineering, Imperial College London, London, UK
| | - Lidong Bie
- Geophysical Institute (GPI), Karlsruhe Institute of Technology, Karlsruhe, Germany
| | - Nicholas Harmon
- University of Southampton, National Oceanography Centre, Southampton, UK
| | - Stephen P Hicks
- Department of Earth Science and Engineering, Imperial College London, London, UK
| | | | - Julie Prytulak
- Department of Earth Sciences, Durham University, Durham, UK
| | - Andreas Rietbrock
- Geophysical Institute (GPI), Karlsruhe Institute of Technology, Karlsruhe, Germany
| | | | - Jon P Davidson
- Department of Earth Sciences, Durham University, Durham, UK
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Amsellem E, Moynier F, Bertrand H, Bouyon A, Mata J, Tappe S, Day JMD. Calcium isotopic evidence for the mantle sources of carbonatites. SCIENCE ADVANCES 2020; 6:eaba3269. [PMID: 32537505 PMCID: PMC7269651 DOI: 10.1126/sciadv.aba3269] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 11/23/2019] [Accepted: 04/01/2020] [Indexed: 06/11/2023]
Abstract
The origin of carbonatites-igneous rocks with more than 50% of carbonate minerals-and whether they originate from a primary mantle source or from recycling of surface materials are still debated. Calcium isotopes have the potential to resolve the origin of carbonatites, since marine carbonates are enriched in the lighter isotopes of Ca compared to the mantle. Here, we report the Ca isotopic compositions for 74 carbonatites and associated silicate rocks from continental and oceanic settings, spanning from 3 billion years ago to the present day, together with O and C isotopic ratios for 37 samples. Calcium-, Mg-, and Fe-rich carbonatites have isotopically lighter Ca than mantle-derived rocks such as basalts and fall within the range of isotopically light Ca from ancient marine carbonates. This signature reflects the composition of the source, which is isotopically light and is consistent with recycling of surface carbonate materials into the mantle.
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Affiliation(s)
- Elsa Amsellem
- Institut de Physique du Globe de Paris, CNRS, Université de Paris, F-75005 Paris, France
| | - Frédéric Moynier
- Institut de Physique du Globe de Paris, CNRS, Université de Paris, F-75005 Paris, France
- Institut Universitaire de France, Paris, France
| | - Hervé Bertrand
- Laboratoire de Géologie de Lyon, Université Lyon 1 and Ecole Normale Supérieure de Lyon, CNRS UMR 5576, 46 allée d’Italie, 69364 Lyon Cedex 07, France
| | - Amaury Bouyon
- Institut de Physique du Globe de Paris, CNRS, Université de Paris, F-75005 Paris, France
| | - João Mata
- Instituto Dom Luiz, Faculdade de Ciências, Universidade de Lisboa, 1749-016 Lisboa, Portugal
| | - Sebastian Tappe
- Department of Geology, University of Johannesburg, 2006 Auckland Park, South Africa
| | - James M. D. Day
- Scripps Institution of Oceanography, University of California San Diego, La Jolla, CA 92093-0244, USA
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