<b>Crustal heterogeneity controls the along-strike segmentation of the northern South China Sea: Insights from scaled analog models</b>

The research explores how crustal heterogeneity, resulting from Mesozoic magmatism, controls the structural segmentation within the northern South China Sea (SCS). Utilizing a series of scaled analogue models, the study demonstrates that rheological variations within the lithosphere significantly influenced the differential deformation patterns observed in the northern SCS. The experiments reveal that the northwest segment, characterized by its Mesozoic magmatic arc, underwent more intense deformation compared to the northeast forearc basin zone. Specifically, the lithosphere exhibits necking within the Mesozoic magmatic arc zone, while a gentle thinning is observed in the forearc zone. This result provides experimental evidence that the Mesozoic magmatism controlled the Cenozoic differential thinning of the northern continental margin of the SCS. The study also highlights the importance of reactivated pre-existing fault zone in modulating fault displacements during the extensional phase, acting as a transitional zone between the northwest and northeast segments.