Abstract
Four parabolic functions were derived separately for the first, the second, the third and the fourth tetrads of lanthanides in samples of leuco-granitic gneiss from Korea, and seawater from off the coasts of Shimane and Kochi prefectures, Japan. We conclude that relative lanthanide abundances in each of those samples are mathematically expressed by a set of four parabolic functions. The parabolic functions are applicable to the abundance ratio values as well as the values of aberration from the cusp-spanning lines. Both parabolic function systems are significant in different senses, but a set of four parabolas for “aberration” is convenient in visualizing the characteristics of lanthanide tetrad phenomenon observed for the sample. Difference in those characteristics can be interpreted to reflect uniquely the state of lanthanides present and/or the condition of genesis of the sample.
