Manganese-Chromium Isotope Systematics of Ivuna, Kainsaz and Other Carbonaceous ChondritesWe have shown earlier that the bulk samples of carbonaceous chondrites [CC] reveal excesses in both Cr-53 (Cr-53*) and Cr-54 (Cr-54*) as compared to the terrestrial standard value. The Cr-53/52 ratios in bulk samples of Orgueil (CI), Murray (CM), Allende (CV), and the Bencubbin/CH-like meteorite Hammadah Al Hambra 237 (HH237) are correlated with the respective Mn/Cr ratios. In contrast to CC, HH237 is characterized by a deficit of Cr-53 (-0.15 +/- 0.10(epsilon)) at a low Mn/Cr ratio of 0.07. The HH237 data point, however, falls on the CC line. Here we report new Mn-53 - Cr-53 results for the CC Kainsaz (CO) and Ivuna (CI).
Shukolyukov, A. (Scripps Institution of Oceanography La Jolla, CA, United States)
Lugmair, G. W. (Scripps Institution of Oceanography La Jolla, CA, United States)
Bogdanovski, O. (Max-Planck-Inst. fuer Chemie Mainz, Germany)