Geodynamic mantle flow model reveals erosion process of North China Craton

Researchers from China University of Geosciences in Beijing, led by Professor Shaofeng Liu, have shed light on the mysterious transformation of the North China Craton (NCC). This research, published in Nature Geoscience, presents a revolutionary model that explains the processes behind the gradual erosion of the craton, which began in the Mesozoic era. Using detailed modeling of mantle flow, Liu’s team traced how Earth’s deep tectonic forces destabilized this ancient part of the continental crust, challenging long-held assumptions about the stability of cratons.

Reconstructing ancient tectonic forces

In a recent study published in natural geosciences, the model suggests subduction beneath the Eurasian plate where the NCC is located. Unlike typical subduction, this plate did not immediately sink into the mantle. Instead, it slid horizontally beneath the NCC’s crust, weakening its foundations in a process known as flat-slab subduction. Using seismic and stratigraphic data, the team reconstructed this tectonic behavior, revealing how this unusual movement triggered chemical reactions that gradually eroded the CNC’s once-stable foundation.

Three stages of deformation

The research identifies three key stages in the deformation of the NCC. First, when the Izanagi plate began to collapse, it exerted horizontal pressure that changed the composition of the NCC foundation. During the second stage, the plate finally retreated, sinking deeper and creating a thinning effect on the lithosphere. This phase of retreat also caused surface uplift and the formation of rift basins. The final stage saw the development of a “mantle wedge” – an area of ​​partially molten material – between the sinking plate and the craton, further eroding the base and promoting volcanic activity.

Implications for geological understanding

This study provides a more nuanced view of how tectonic and mantle forces interact to erode stable crustal structures over time. Liu’s model provides insight into the transformation of the NCC and improves our understanding of the stability of cratons, with practical implications for the exploration of technology-critical mineral deposits. The research paves the way for future studies of the complex life cycles of Earth’s crustal plates, providing a window into the ancient geological processes that shape the modern landscape.