1-s2.0-S0012821X17300353-gr001.sml

Fig. 1. Variation of Cu contents of Martian meteorites with MgO contents. Overall, Cu and MgO in different groups of shergottites show a broadly negative correlation ([Cu] μg/g = −0.42 * [MgO] wt.% + 14.9, R2 = 0.80, n = 12, including olivine in shergottites). The estimated Cu content of the Martian mantle is from Taylor (2013) and confirmed by our new data. Multiple analyses of the same sample in the literature (Meyer, 2013) and the new data occasionally show variable Cu contents (dashed lines indicate samples where large differences have been reported), indicating the effect of sample heterogeneity on Cu abundances. Copper contents in three olivines from shergottites measured by laser ablation ICP-MS in Yang et al. (2015) were 3–7 μg/g or below the detect limit of 0.1 μg/g. Considering the low Cu content in ALH 84001 and the low bulk rock abundances of Cu in most shergottites, olivine should have very low Cu contents. Thus olivine is assumed to have low Cu contents of <0.1 μg/g.