Geological implications of a permeability-depth curve for the continental crust

摘要: The decrease in permeability ( k ) of the continental crust with depth z ), as constrained by geothermal data and calculated fluid flux during metamorphism, is given log = −14 − 3.2 z, where meters squared kilometers. At moderate to great crustal depths (>∼5 km), this curve defined mainly from prograde metamorphic systems, thus applicable orogenic belts being thickened and/or heated; lower permeabilities may occur stable cratonic regions. This k-z relation implies that typical values ∼10−11 m/s are consistent pressures significantly above hydrostatic values. also predicts CO2 large orogens be sufficient cause significant climatic effects, if retrograde carbonation reactions minimal, suggests a capacity for diffuse degassing Earth (1015–1016 g/yr) tectonically active