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Reading: Davis (2006)
1. Provide a plausible interpretation for the CV and EH chondrite data in Fig. 2, assuming that volatility fractionation of condensates was responsible. Your answer should address the tendency for elemental abundance to increase with respect to condensation temperature for CV chondrites, and to reach a maximum at intermediate condensation temperatures for EH chondrites.
2. What inference can be made for the nature of volatility fractionations in meteorites and planetary bodies based on isotopic studies?
3. Explain how pre-solar grain abundances can be used to infer processes related to volatility fractionation.
4. Create a table that summarizes at least 4 different models for explaining how volatility fractionation occurred in the solar system, and the problems with these models. Your table should have one column that describes the model, and one column that describes the apparent pitfalls.
5. According to Davis (p. 302), Group II CAIs contain isotopically light Mg and Si (i.e., relatively low 25Mg/24Mg, and low 29Si/28Si, low 30Si/28Si) but are known (based on their trace-element compositions, particularly for the rare earth elements) to have formed by condensation. Devise a model for explaining how these objects formed, considering that high-temperature condensation should produce negligible isotopic fractionation.