We present a self-consistent crustal accretion model of Iceland that includes heat and mass transfer between an unwelling, melting and an accreting, cooling crust. This models predicts sub-solidus crustal temperatures that are consistent with seismic estimates of the maximum depth of the earthquake hypocenters and mid-crustal shear wave quality factors, and with geothermal estimates of surface heatflow. ¿ American Geophysical Union 1995