An alternative explanation for the Hf-Nd mantle array

The ^(176)Hf/^(177)Hf and143Nd/144Nd of mid-ocean ridge basalts(MORB)and ocean island basalts(OIB)are significantly correlated and form the so-called Hf-Nd mantle array[1,2](Fig.1a).Model calculations show that the association of OIB with the array is inconsistent with the distinctive Hf and Nd isotopic compositions of their purported ancient sediment sources in the mantle[1].A current consensus for the origin of the array is that the Lu/Hf

The ^176Hf/^177Hf and ^143Nd/^144Nd of mid-ocean ridge basalts （MORB） and ocean island basalts （OIB） are significantly correlated and form the so-called Hf-Nd mantle array [1,2] （Fig. la）.