Table 1.
Carbon and Oxygen Isotope Compositions and Δ (Δ47raw) Values of Gases Heated at 1000°C (HG; WG, CARBA, and LINDE), ETH Standards, and Gases Equilibrated at 25°C (EG) Used to Create the Reference Frame and Establish Accepted Values for the ETH Standards in 2013
| Gas label | δ 13C (‰) (VPDB) | δ 18O (‰) (VPDB) | Δ (Δ47raw) (ppm) |
|---|---|---|---|
| WG, HG | −7.25 | 0.26 | 0 |
| Carba, HG | −28.6 | −17.68 | −1.0 |
| Linde, HG | −48.85 | −23.87 | 5.6 |
| ETH1 | 2.20 | 6.70 | −0.6 |
| ETH2 | −10.0 | −10.0 | −5.7 |
| ETH3 | 1.95 | 7.18 | −0.1 |
| ETH4 | −10.0 | −10.0 | −5.7 |
| EG WG + enriched | −6.96 | 29.40 | 20.1 |
| EG WG + enriched | −6.97 | 30.73 | 21.0 |
| EG WG + enriched | −7.03 | 31.02 | 21.3 |
| EG Linde + tap | −47.97 | −0.96 | 21.1 |
| EG Linde + tap | −48.01 | −1.05 | 21.0 |
| EG Linde + tap | −47.94 | −0.89 | 21.1 |
| EG WG + tap | −6.06 | 1.84 | 0.5 |
| EG WG + tap | −7.04 | −0.23 | −0.5 |
Note. The δ 18O values of the standards are given without a correction for the acid fractionation. Δ (Δ47raw) is the change in Δ47raw resulting from the use of the Brand parameters instead of the Huntington ones as calculated with equation (10) of Daëron et al. (2016). For explanations see text. VPDB = Vienna Peedee belemnite; WG = working gas.