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Oxygen isotope composition of main-group pallasites and mesosiderites. Data for main-group pallasites and mesosiderites from Greenwood et al. (2006). Solid lines through data points show the mean Δ17O value for each group. Grey-shaded boxes depict the 2σ error on the mesosiderite and main-group pallasite population Δ17O and δ18O mean values. Open squares are individual mesosiderite analyses, open circles individual pallasite analyses. The dashed line labelled (1) is the eucrite fractionation line of Greenwood et al. (2005); the dashed line labelled (2) shows the range of HED values obtained by Weichert et al. (2004). Δ17O is linearized using the format of Miller (2002): Δ17O = 1000 ln (1+ (δ17O/1000)) – λ1000 ln (1+ ( δ18O/1000)) where λ = 0.5247. TFL = Terrestrial Fractionation Line. |
δ18O | δ17O | Δ17O: given | Δ17O: Miller (2002) | Comment |
---|---|---|---|---|
3.0100 | 0.1800 | -1.3900 | -1.398 |
Name | Class | δ18O | δ17O | Δ17O: calc | Δ δ18O | Δ δ17O | Δ Δ17O |
---|---|---|---|---|---|---|---|
Northwest Africa 468 | Iron, IAB-ung | 3.0100 | 0.1800 | -1.398 | 0 | 0 | 0 |
Tafassasset | Achondrite-prim | 2.9400 | 0.1800 | -1.362 | -0.07 | 0 | 0.04 |
Northwest Africa 8545 | Achondrite-ung | 3.1590 | 0.1200 | -1.536 | 0.15 | -0.06 | -0.14 |
Northwest Africa 8158 | Eucrite | 3.0220 | 0.0000 | -1.585 | 0.01 | -0.18 | -0.19 |
Northwest Africa 8545 | Achondrite-ung | 2.9660 | 0.0040 | -1.551 | -0.04 | -0.18 | -0.15 |
Northwest Africa 8287 | Acapulcoite | 2.9440 | 0.3560 | -1.188 | -0.07 | 0.18 | 0.21 |
Northwest Africa 2400 | Achondrite-ung | 3.2700 | 0.1500 | -1.565 | 0.26 | -0.03 | -0.17 |
Northwest Africa 6921 | CR6 | 3.1810 | -0.0650 | -1.733 | 0.17 | -0.25 | -0.33 |
Northwest Africa 12869 | Achondrite-prim | 3.1810 | -0.0720 | -1.74 | 0.17 | -0.25 | -0.34 |
Northwest Africa 3250 | Achondrite-prim | 3.2500 | -0.0300 | -1.734 | 0.24 | -0.21 | -0.34 |
Northwest Africa 2994 | Chondrite-ung | 3.3550 | 0.0780 | -1.681 | 0.35 | -0.1 | -0.28 |
Northwest Africa 2994 | Chondrite-ung | 3.3310 | -0.0070 | -1.754 | 0.32 | -0.19 | -0.36 |
Northwest Africa 8287 | Acapulcoite | 3.2000 | 0.5000 | -1.178 | 0.19 | 0.32 | 0.22 |
Northwest Africa 5782 | Acapulcoite/lodranite | 3.2400 | 0.5300 | -1.169 | 0.23 | 0.35 | 0.23 |
Northwest Africa 8287 | Acapulcoite | 2.5850 | 0.2360 | -1.12 | -0.43 | 0.06 | 0.28 |
Northwest Africa 6557 | Acapulcoite | 2.7900 | 0.5500 | -0.913 | -0.22 | 0.37 | 0.49 |
Northwest Africa 4529 | Lodranite | 2.8940 | 0.6130 | -0.905 | -0.12 | 0.43 | 0.49 |
Northwest Africa 6557 | Acapulcoite | 3.0500 | 0.6400 | -0.96 | 0.04 | 0.46 | 0.44 |
Northwest Africa 5782 | Acapulcoite/lodranite | 3.0300 | 0.6600 | -0.929 | 0.02 | 0.48 | 0.47 |
Northwest Africa 4448 | Lodranite | 3.4130 | 0.4420 | -1.348 | 0.4 | 0.26 | 0.05 |
Northwest Africa 6901 | Achondrite-prim | 2.7700 | -0.2500 | -1.703 | -0.24 | -0.43 | -0.3 |