The Cu isotopic composition of iron meteorites

Abstract

Abstract-High-precision Cu isotopic compositions have been measured for the metal phase of 29 iron meteorites from various groups and for four terrestrial standards. Cu. This correlation between nonmass-dependent and mass-dependent parameters suggests that the Cu isotopic composition of iron meteorites has not been modified by planetary differentiation to a large extent. Therefore, Cu isotopic ratios can be used to confirm genetic links. Cu isotopes thus confirm genetic relationships between groups of iron meteorites (e.g., IAB and IIICD; IIIE and IIIAB); and between iron meteorites and chondrites (e.g., IIE and H chondrites). Several genetic connections between iron meteorites groups are confirmed by Cu isotopes, (e.g., IAB and IIICD; IIIE and IIIAB); and between iron meteorites and chondrites (e.g., IIE and H chondrites).

Zinc isotopic composition of iron meteorites: Absence of isotopic anomalies and origin of the volatile element depletion

“…This discrepancy might be due to the limited number of samples analyzed in Luck et al (2005) compared with the present study. It is also possible that local heterogeneities in composition may render the difference in the d 66 Znd 65 Cu trend, however, Zn (this study) and Cu (Bishop et al 2012) isotope measurements were conducted from the same parent chip, indicating the positive trend by our data should be reliable. The positive trend in the IAB group is likely the result of evaporation, as Cu and Zn are both moderately volatile elements; therefore, the Zn and Cu isotopes should be affected at the same time.…”

“…Similarly, despite the depletion of Cu, the Cu isotopic compositions of the IVA iron meteorites (−1.83‰ < δ 65 Cu < −0.35‰; Bishop et al. ) also fall in the range of carbonaceous chondrites (−1.51‰ < δ 65 Cu < 0.07‰; Luck et al. ; Barrat et al.…”

“…Some of these samples were cut in half for Cu and Zn isotope analysis, respectively, and the Cu isotope compositions were reported in Bishop et al. (). Zn data of Campo del Cielo, Casas Grandes, and Charcas obtained from Luck et al.…”

“…For all the irons, large chips with no visible sulfides and silicate inclusions were selected. Some of these samples were cut in half for Cu and Zn isotope analysis, respectively, and the Cu isotope compositions were reported in Bishop et al (2012). Zn data of Campo del Cielo, Casas Grandes, and Charcas obtained from Luck et al (2005) were incorporated to further characterize the group IAB and IIIAB.…”

“…The recent development of multiple-collector inductively coupled-plasma mass-spectrometry (MC-ICP-MS) has allowed for high-precision measurements of nontraditional stable isotopes. These isotope ratios have been used as new tracers to study planetary formation and differentiation: Si (Georg et al 2007;Fitoussi and Bourdon 2012;Pringle et al 2013;, Fe (Poitrasson et al 2004;Wang et al 2012), Ni (Moynier et al 2007), Cu (Luck et al 2003;Williams and Archer 2011;Bishop et al 2012), Zn (Luck et al 2005;Moynier et al 2007;Paniello et al 2012a), Ge (Luais 2007), Cd (Wombacher et al 2008), and Sr .…”