Global lithospheric thickness reconstruction using machine learning

The lithosphere, as the outermost solid layer of our planet, preserves a progressively more fragmentary record of geological events and processes from Earth's history the further back in time one looks. Thus, the evolution of lithospheric thickness and its cascading impacts on Earth’s tectonic system are presently unknown. Herein, we track the lithospheric thickness history using machine learning based on lithogeochemical big data of basalt. Our results demonstrate that four dramatic lithospheric thinning events occurred during the Paleoarchean, early Paleoproterozoic, Neoproterozoic, and Phanerozoic with intermediate thickening scenarios. These events respectively correspond to supercontinent breakup and assembly periods. Causality investigation further indicates that crustal metamorphic and deformation styles are the feedback of lithospheric thickness. Cross-correlation between lithospheric thickness and metamorphic thermal gradients record the transition from intra-oceanic subduction...