Fig. 2.

The μ²⁶Mg* and μ⁵⁴Cr compositions of metal-rich chondrites and their components. Uncertainties reflect the external reproducibility or internal errors, whichever is larger. Some of the μ⁵⁴Cr uncertainties are smaller than symbols. The green box represents the predicted μ⁵⁴Cr and μ²⁶Mg* compositions of the ²⁶Al-free and thermally unprocessed molecular cloud material, including their uncertainties. The plotted compositions of Isheyevo lithic clasts and CB chondrules represent averages of individual samples. The metal-rich chondrites and their components define a negative correlated array with a slope of 0.039 ± 0.018 that intercepts the Solar System correlation line at a μ⁵⁴Cr value of 89 ± 20 ppm. Note that admixing of CAIs to a CI-like composition cannot account for the trend defined by metal-rich chondrites, as this would result in a mixing hyperbola that falls below the inner Solar System correlation line.