Tectonic overpressure at shallow depth in the lithosphere: The effects of boundary conditions

摘要: Abstract In dynamic geological settings, the total pressure (P) comprises and (litho)static (PL) components, which are indistinguishable when is estimated thermodynamically. The difference between two components called tectonic overpressure (here defined as TOP = P/PL), magnitude of has been debated for decades in geodynamics. this paper, we report on a parametric study carried out to evaluate TOP various geodynamic settings under variable boundary conditions. brittle frictional field limited by strength cohesion rocks, pore fluid pressure; viscous it dependent viscosity flow configuration. We analyse using Navier-Stokes' equation with gravity, conclude that there some configurations conditions favourable development high (>2) at relatively shallow lithospheric levels, so facilitating exhumation high- ultrahigh-pressure rocks subduction channels. This case upward tapering channels, rigid or deformable walls, no outlet condition bottom. Natural zones characterized non-steady behaviour over time space; therefore, if zone transiently goes through mentioned above, can be >2 rapidly exhumed surface return close hanging wall.