In order to assess whether material differentiated shortly after terrestrial accretion is still present in the deep mantle, we investigated hot spot basalts for 142Nd/144Nd anomalies that could attest for the presence of live 146Sm (T1/2 = 103 My) at the time the mantle source of these basalts formed. We analyzed high 3He/4He basalts from Loihi and Ethiopia and normal 3He/4He basalts from Iceland. Although the 143Nd/144Nd ratios of these basalts reflect a source with long-term LREE (light rare earth elements) depletion, no resolvable 142Nd anomalies were detected. Taking the analytical uncertainties (10--20 ppm) into account, however, the present results do not rule out the possibility that a large proportion of material fractionated very early in the Earth's history may still be hidden in the deep mantle.