Fig. 3.

(a) Ternary Si-Fe-Mg diagram showing the composition of several different points in 7 Antarctic micrometeorite grains (AMMs) investigated in this work. Olivine and pyroxene are represented by gray lines. Dotted and dashed circles are ranges for each group of carbonaceous chondrites (C1 (CI1), C2 (CM2, CR2 and Tagish Lake), C3 (CO3 and CV3). CI1, CM2, CR2, CO3 and CV3 data from McSween and Richardson (1977) and Zolensky et al. (1993). Tagish Lake data from Greshake et al. (2005)). (b) Ternary Si-Fe-Mg diagram of other AMM data from Kurat et al. (1994), Engrand et al. (1999), Genge et al. (1997) and Gounelle et al. (2005).