Skip to Main Content


Earth differentiation is considered to be advanced but incomplete, and to be proceeding largely through the agencies of liquid or creep convection, diffusion, and igneous intrusion. Seafloor-spreading (Fig. 3) rates up to 4.5 cm per year (Heirtzler, 1968), when compared with the proportion of uranium believed transferred to the crust, suggest that convection velocities may be greater than the transfer rate and, therefore, that uranium and thorium in convection cells may have been recycled and a proportion bled off for transfer during each cycle.

Figures & Tables





Citing Books via

Close Modal
This Feature Is Available To Subscribers Only

Sign In or Create an Account

Close Modal
Close Modal