The transition from ancient to modern-style tectonics: Insights from lithosphere dynamics modelling in compressional regimes

Orogens are traditionally classified according to their tectonic style. Paleoproterozoic tectonics is referred as “ancient-style tectonics” while Proterozoic “modern-style tectonics”. Ancient-style characterised by distributed vertical structures and low topography gradients, often associated with diapirism partial melting. In contrast, modern-style involve prominent strain localisation the formation of thrusts, nappes high topographic gradients. However, parameters controlling transition from ancient poorly understood. To quantify this transition, a combination 1D 2D resolution lithospheric-scale thermo-mechanical models was conducted. The strength lithosphere (i.e., Moho temperature, rate, crustal rheology, radiogenic heat production role shear heating) were investigated in detail. Our results show that style controlled maximum (shear stress). Modern-style observed occur when greater than 300 MPa. At opposite, lower MPa leads structures. Therefore, temperature background rate significantly influence tectonics. Shear heating remains key factor promoting Crustal has moderate increasing/decreasing tendency for faulting within crust. This criterion also provides an excellent fit second potential proxy: ca. 225°C. These two proposed proxies can be used interchangeably predict