Neutron capture on Pt isotopes in iron meteorites and the Hf–W chronology of core formation in planetesimals

Tafassasset: Evidence of early incipient differentiation on a metal-rich chondritic parent body

“…Connelly et al, 2012), confirming earlier inferences based upon angrites (Baker et al, 2005;Kleine et al, 2009) and iron meteorites (e.g. Kleine et al, 2005;Kruijer et al, 2013;Markowski et al, 2006;Qin et al, 2008;Schersten et al, 2006).…”

Pd–Ag chronometry of iron meteorites: Correction of neutron capture-effects and application to the cooling history of differentiated protoplanets

“…Quantifying cosmic ray-induced effects on Ag isotopes requires an independent neutron-dose proxy for iron meteorites, and a model linking this dosimeter to the effects on the 107 Ag/ 109 Ag ratio. To this end we have extended the model calculations of cosmogenic effects on Pd-Ag systematics from Leya and Masarik (2013) with calculations of neutron capture effects on Pt isotopes, which provide a powerful neutron-dose proxy for iron meteorites (Kruijer et al, 2013;Wittig et al, 2013). The updated model makes it possible to correct cosmogenic effects on 107 Ag/ 109 Ag using measured Pt isotope compositions.…”

Age of Jupiter inferred from the distinct genetics and formation times of meteorites

“…After digestion of the iron meteorites in concentrated HNO 3 -HCl (2:1), the sample solutions were split into a fraction for W and Mo (∼90%) and for Pt (∼10%) isotope analysis. The chemical separation of W, Pt, and Mo was accomplished using ion exchange chromatography following previously published procedures (6,12,15,36 …”