![]() |
||
|
Oxygen isotope composition of primitive achondrites (SNCs shown for comparison). Data for brachinites, winonaites, acapulcoite-lodranite clan from Greenwood et al. (2012). Data for ureilites from Clayton and Mayeda (1999). Data for Martian meteorites (SNCs) from Franchi et al. (1999) and compiled from laser fluorination analyses in the Meteoritical Bulletin. Δ17O calculated as: Δ17O = δ17O – 0.52δ18O. Individual winonaite and acapulcoite-lodranite clan samples are very highly susceptible to terrestrial weathering resulting in large shifts in δ18O and to a lesser extent Δ17O. Most analysis points for these two groups plotted on this diagram have been cleaned in EATG (ethanolamine thioglycollate) in order to reduce the influence of terrestrial weathering (see Greenwood et al., 2012 for further details). TFL: terrestrial fractionation line, Y&R: slope 1 line (Young and Russell, 1998), CCAM: carbonaceous chondrite anhydrous mineral line (Clayton et al., 1977; Clayton and Mayeda 1999). |
δ18O | δ17O | Δ17O: given | Δ17O: linear | Comment |
---|---|---|---|---|
8.4500 | 3.5800 | Not given | -0.814 |
Name | Class | δ18O | δ17O | Δ17O: calc | Δ δ18O | Δ δ17O | Δ Δ17O |
---|---|---|---|---|---|---|---|
Northwest Africa 11483 | Ureilite | 8.4500 | 3.5800 | -0.814 | 0 | 0 | 0 |
Northwest Africa 11558 | Achondrite-ung | 8.5300 | 3.5250 | -0.911 | 0.08 | -0.06 | -0.1 |
Caleta el Cobre 050 | Achondrite-ung | 8.2800 | 3.4800 | -0.826 | -0.17 | -0.1 | -0.01 |
Northwest Africa 12939 | Ureilite | 8.6660 | 3.5040 | -1.002 | 0.22 | -0.08 | -0.19 |
Northwest Africa 7325 | Achondrite-ung | 8.2040 | 3.6700 | -0.596 | -0.25 | 0.09 | 0.22 |
Tin-Essako 001 | Achondrite-ung | 8.1640 | 3.6630 | -0.582 | -0.29 | 0.08 | 0.23 |
Northwest Africa 12209 | Ureilite | 8.2060 | 3.4020 | -0.865 | -0.24 | -0.18 | -0.05 |
Northwest Africa 12205 | Ureilite | 8.2060 | 3.7710 | -0.496 | -0.24 | 0.19 | 0.32 |
Northwest Africa 11119 | Achondrite-ung | 8.2260 | 3.3640 | -0.914 | -0.22 | -0.22 | -0.1 |
Northwest Africa 11951 | Ureilite | 8.6700 | 3.8320 | -0.676 | 0.22 | 0.25 | 0.14 |
Northwest Africa 2895 | Ureilite | 8.2430 | 3.2700 | -1.016 | -0.21 | -0.31 | -0.2 |
Northwest Africa 11119 | Achondrite-ung | 8.1210 | 3.3980 | -0.825 | -0.33 | -0.18 | -0.01 |
Northwest Africa 4519 | Ureilite | 8.2000 | 3.2900 | -0.974 | -0.25 | -0.29 | -0.16 |
Northwest Africa 12939 | Ureilite | 8.1850 | 3.2570 | -0.999 | -0.26 | -0.32 | -0.19 |
Northwest Africa 7111 | Ureilite | 8.1200 | 3.3030 | -0.919 | -0.33 | -0.28 | -0.11 |
Errachidia 004 | Winonaite | 8.1970 | 3.9400 | -0.322 | -0.25 | 0.36 | 0.49 |
Northwest Africa 4520 | Ureilite | 8.0700 | 3.3200 | -0.876 | -0.38 | -0.26 | -0.06 |
Northwest Africa 11950 | Ureilite | 8.8850 | 3.7330 | -0.887 | 0.44 | 0.15 | -0.07 |
Northwest Africa 11951 | Ureilite | 8.8340 | 3.8610 | -0.733 | 0.38 | 0.28 | 0.08 |
Dar al Gani 1066 | Ureilite-pmict | 8.7900 | 3.9200 | -0.651 | 0.34 | 0.34 | 0.16 |