A simple 1-D model is developed for the release of He (and Ar) from a solid lithology to the intervening porefluid as a result of fracturing. The results indicate that fracturing can release the solid phase accumulated He on a geologically short time-scale (<1500 yrs) for large crustal sections and can lead to the (observed) decoupling of He and Ar degassing fluxes from a homogeneous crust. Measurement of regional variations in the crustal degassing fluxes may therefore provide a useful constraint on time-dependent hydraulic control of large-scale fluid transport in the Earth's crust. ¿American Geophysical Union 1991