The difference in lanthanide abundance pattern between the crust and the chondrite and its possible meaning to the genesis of crust and mantle

Abstract

First the following assumptions were made: (1) earth's lithosphere encountered complete melting at a certain period, (2) successive solidification of the melt resulted in the formation of mantle and crust, (3) the partition coefficient between the solid and liquid phases for lanthanides were constant through all the stages of solidification which led to the formation of mantle, and (4) the initial terrestrial abundance ratios of lanthanides were the same as those observed in chondrites. Mathematical treatment based on these assumptions enabled us to obtain a reasonable interpretation of the pattern variation of lanthanides and their concentration in the average crust and in the Norton County achondrite. In addition this study gave us a new approach to estimate the crust-mantle weight ratio independently of geophysics. Finally we arrived at a formula for calculation of the partition coefficients of minor elements from the concentration ratios between earth's crust and chondrite.