Abstract
Ce and Nd isotope ratios and REE contents of one carbonaceous chondrite (Murchison), 3 ordinary chondrites (Granès, Holbrook and Barwise) and 4 achondrites (Camel Donga, Juvinas, two pieces of Millbillillie) were measured. For the Ce isotope analysis of meteorite samples the new chemistry for extracting Ce from the gel formed after decomposition of ∼1-g chondrite sample with Mg content of 20% was developed with a recovery yield of 80%. The initial Ce isotope ratio of each meteorite sample was calculated with the assumption that the age of meteorite samples is 4.56 Ga, and the average value was obtained to be 138Ce/ 142Ce−0.0225321 ± 0.0000007 (2σ), which is considered to be the primordial Ce isotopic composition of the solar system. The average of the present-day Ce isotope ratios of the chondrites of this study and that previously published by Shimizu et al. is 0.0225653, which suggests that the estimation of the Ce isotope ratio of the present-day bulk Earth of 0.0225652 that was published by Makishima and Nakamura is convincing. The Ce isotope ratio of the present-day bulk Earth of 0.0225652 gives the 138La/ 142Ce ratio of the bulk Earth to be 0.00306 ± 0.00006 (2σ), which corresponds to La/Ce = 0.375 ± 0.007 (2σ). We propose that the La/Ce ratio of 0.375 represents that of the bulk Earth or CHUR.
Sign-in/Register to access full text options 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a callDisclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.
