ABSTRACT

Based on accurate determinations of REE abundances in chondrites, fine structures of REE patterns for lunar materials were reviewed. It was found that highland basalts represented by the Apollo 14 samples and KREEP, and certain samples taken from mare regions, which have “straight” REE patterns, showed positive Ce anomalies (several to ten per cent, relative to the Leedey chondrite). On the other hand, the mare basalts which have “curved” REE patterns exhibit no or little anomaly of Ce. In addition, the Ce abundances of Apollo 16 anorthosites are normal viewed from the smooth curve spanning from La to Nd and Sm. These features are considered to be of much significance for the history of the lunar materials.