Some alkali, alkaline Earth, and rare Earth element concentrations and the Rb-Sr age of the lost city meteorite and separated phases

Abstract

The Lost City chondritic meteorite and mineral concentrates from it were analyzed by mass-spectrometric isotope dilution. Concentrations of the alkali elements Li, K, and Rb; alkaline earth elements Ba and Sr; and rare earth elements Ce, Nd, Sm, Eu, Gd, Dy, Er, Yb, and Lu in the bulk sample are quite typical of ordinary chondrites, except for a small (approximately 10%) negative Eu anomaly. At least 30 to 60% of the rare earth elements are not located in the major phases of Lost City and presumably are in a minor phosphate phase or phases. A Rb-Sr model age of 4.68 b.y. is obtained for the meteorite; data on mineral concentrates, however, suggest that radiogenic Sr has migrated within the system.