Nonlinearity of the post-spinel transition and its expression in slabs and plumes worldwide

Junjie Dong; Rebecca A Fischer; Lars P Stixrude; Matthew C Brennan; Kierstin Daviau; Terry-Ann Suer; Katlyn M Turner; Yue Meng; Vitali B Prakapenka

doi:10.1038/s41467-025-56231-z

Nonlinearity of the post-spinel transition and its expression in slabs and plumes worldwide

Nat Commun. 2025 Jan 26;16(1):1039. doi: 10.1038/s41467-025-56231-z.

Authors

Junjie Dong^{1

2

3}, Rebecca A Fischer⁴, Lars P Stixrude⁵, Matthew C Brennan^{4

6}, Kierstin Daviau^{4

7}, Terry-Ann Suer^{4

8}, Katlyn M Turner^{4

9}, Yue Meng¹⁰, Vitali B Prakapenka¹¹

Affiliations

¹ Department of Earth and Planetary Sciences, Harvard University, Cambridge, Massachusetts, USA. dong2j@caltech.edu.
² Department of the History of Science, Harvard University, Cambridge, Massachusetts, USA. dong2j@caltech.edu.
³ Now at Division of Geological and Planetary Sciences, California Institute of Technology, Pasadena, California, USA. dong2j@caltech.edu.
⁴ Department of Earth and Planetary Sciences, Harvard University, Cambridge, Massachusetts, USA.
⁵ Department of Earth, Planetary, and Space Sciences, University of California, Los Angeles, California, USA.
⁶ Now at Shock and Detonation Physics Group, Los Alamos National Laboratory, Los Alamos, NM, USA.
⁷ Now at Toi-Ohomai Institute of Technology, Tauranga, New Zealand and School of Science, University of Waikato, Tauranga, New Zealand.
⁸ Now at Laboratory for Laser Energetics, University of Rochester, Rochester, New York, USA.
⁹ Now at MIT Media Lab, Massachusetts Institute of Technology, Cambridge, Massachusetts, USA.
¹⁰ High Pressure Collaborative Access Team (HPCAT), X-Ray Science Division, Argonne National Laboratory, Argonne, IL, USA.
¹¹ Center for Advanced Radiation Sources, University of Chicago, Chicago, IL, USA.

Abstract

Phase transitions in the mantle control its internal dynamics and structure. The post-spinel transition marks the upper-lower mantle boundary, where ringwoodite dissociates into bridgmanite plus ferropericlase, and its Clapeyron slope regulates mantle flow across it. This interaction has previously been assumed to have no lateral spatial variations, based on the assumption of a linear post-spinel boundary in pressure and temperature. Here we present laser-heated diamond anvil cell experiments with synchrotron X-ray diffraction to better constrain this boundary, especially at higher temperatures. Combining our data with results from the literature, and using a global analysis based on machine learning, we find a pronounced nonlinearity in the post-spinel boundary, with its slope ranging from -4 MPa/K at 2100 K, to -2 MPa/K at 1950 K, and to 0 MPa/K at 1600 K. Changes in temperature over time and space can therefore cause the post-spinel transition to have variable effects on mantle convection and the movement of subducting slabs and upwelling plumes.

Abstract

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