title: Chondrite barium, neodymium, and samarium isotopic heterogeneity and early Earth differentiation.
abstract: Isotopic variability in barium, neodymium, and samarium in carbonaceous chondrites reflects the distinct stellar nucleosynthetic contributions to the early solar system. We used 148Nd/144Nd to correct for the observed s-process deficiency, which produced a chondrite 146Sm-142Nd isochron consistent with previous estimates of the initial solar system abundance of 146Sm and a 142Nd/144Nd at average chondrite Sm/Nd ratio that is lower than that measured in terrestrial rocks by 21 +/- 3 parts per million. This result strengthens the conclusion that the deficiency in 142Nd in chondrites relative to terrestrial rocks reflects 146Sm decayand earlyplanetary differentiation processes.
authors.affiliation: Department of Terrestrial Magnetism, Carnegie Institution of Washington, 5241 Broad Branch Road, NW, Washington, DC 20015, USA. carlson@dtm.ciw.edu
authors.forename: Richard W
authors.initials: RW
authors.lastname: Carlson
authors.forename: Maud
authors.initials: M
authors.lastname: Boyet
authors.forename: Mary
authors.initials: M
authors.lastname: Horan