The Nd/Nd variations in mantle-derived rocks provide constraints on the stirring rate of the mantle from the Hadean to the present.

Early silicate differentiation events for the terrestrial planets can be traced with the short-lived Sm-Nd system (100-My half-life). Resulting early Earth-produced Nd/Nd variations are an excellent tracer of the rate of mantle mixing and thus a potential tracer of plate tectonics through time. Evidence for early silicate differentiation in the Hadean (4.