Table 1. Summary table of the f (V) – f (Sr) linear functions required to reproduce the CAI correlation line in δ51V-δ88Sr space, starting from a nebular gas of chondritic composition.
Given that the fractionation factor between two isotopes/isotopologs depends on the inverse square root of their respective masses (Supplementary Materials), considering different V- and Sr-bearing species produces condensation/evaporation lines with variable slopes in δ51V-δ88Sr space. To reproduce the δ51V-δ88Sr correlation line observed in CAIs from the variable slopes presented in Fig. 3 therefore requires the difference in volatility between the two considered elements to be adjusted. For each combination of V- and Sr-bearing species (53), we numerically search for the f (V) – f (Sr) linear relationship that enables reproducing the δ51V-δ88Sr correlation line observed in CAIs. Assuming that γV = γSr, we compute the modeled range of ∆T50(V-Sr) values during condensation, here reported in italic (see Fig. 4).
| V | VO | VO2 | ||
| Condensation | Sr | f(V) = 0.6781 × f(Sr) + 0.3274 | f(V) = 1.0513 × f(Sr) − 0.0406 | f(V) = 1.5051 × f(Sr) − 0.4871 |
| ∆T50 (V-Sr) | +6 to +25 (K) | −1 to 0 (K) | −16 to −4 (K) | |
| SrO | f(V) = 0.5112 × f(Sr) + 0.4932 | f(V) = 0.7927 × f(Sr) + 0.2162 | f(V) = 1.1350 × f(Sr) − 0.1196 | |
| ∆T50 (V-Sr) | +13 to +49 (K) | +4 to +14 (K) | −5 to −1 (K) | |
| Evaporation | Sr | f(V) = 0.8130 × f(Sr) + 0.1597 | f(V) = 1.0437 × f(Sr) − 0.0796 | f(V) = 1.2630 × f(Sr) − 0.3076 |
| SrO | f(V) = 06947 × f(Sr) + 0.2780 | f(V) = 0.8919 × f(Sr) + 0.0722 | f(V) = 1.0794 × f(Sr) − 0.1238 |