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

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 fro

SUBMITTER: Dong J 

PROVIDER: S-EPMC11762276 | biostudies-literature | 2025 Jan

REPOSITORIES: biostudies-literature