Origin of Meteoric Fluids in Extensional Detachments

Figure 4

Fluid overpressure resulting from exhumation and fluid flow. (a) Initial situation where fluid pressure equals lithostatic pressure. (b) For a given rock volume, exhumation results in an upward shift along the lithostatic pressure gradient. Trapped pore fluid maintains its pore pressure and becomes overpressured. (c) Fluid flow will lead to a decrease of the fluid pressure gradient, increasing the overpressure downstream.