Seismic detection of the deep carbon cycle

Petrologic studies suggest that carbonate-rich melts are present in the Earth’s upper mantle and play an important role in the deep carbon cycle. However, seismic detection of these melts is difficult due to the lack of understanding of the elastic properties of carbonate melts. In this study, we have successfully determined the sound velocity and density of a dolomite melt at upper mantle conditions using high-pressure experiments and theoretical simulations. The calculated velocities of carbonate melt-bearing mantle using these new elasticity data were compared with global seismic observations. The result suggests that ~0.05% carbonate-rich melt can be pervasively present in the deep upper mantle, implying a global average mantle carbon concentration of 80-140 ppm. This work has been published in PNAS.

Check the links below for media reports and highlights on our work!

CWRU highlight: https://thedaily.case.edu/understanding-the-deep-carbon-cycle/

FSU highlight: https://news.fsu.edu/news/2020/08/03/fsu-geologists-publish-new-findings-on-carbonate-melts-in-earths-mantle/

SUSTech highlight: https://ess.sustech.edu.cn/New-detail-id-404.html

APS highlight: https://www.aps.anl.gov/APS-Science-Highlight/2021-09-20/carbonate-induced-melting-in-the-deep-upper-mantle

Phys.org report: https://phys.org/news/2020-09-deep-carbon.html

ScienceDaily report: https://www.sciencedaily.com/releases/2020/08/200804165112.htm

Relevant Publications

Xu, M., Jing, Z., Bajgain, S. K., Mookherjee, M., Van Orman, J. A., Yu, T., & Wang, Y. (2020). High-pressure elastic properties of dolomite melt supporting carbonate-induced melting in deep upper mantle. Proceedings of the National Academy of Sciences, 117(31),18285-18291.