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. Author manuscript; available in PMC: 2019 Mar 1.
Published in final edited form as: Geochim Cosmochim Acta. 2017 Dec 16;224:116–131. doi: 10.1016/j.gca.2017.12.013

Figure 7:

Figure 7:

Plot showing host Δ17O values and Mg#’s of chondrules superimposed by oxygen isotope mixing curves of constant dust enrichment and ice enhancement from the model of Tenner et al. (2015). The model adopts the following Δ17O values for the various oxygen reservoirs: anhydrous silicate dust, −8.0‰; Solar gas, −28.4‰; water ice, +2.0‰; organics in the dust, +11.3‰. Inferred anhydrous dust enrichment and ice enhancement factors for type I chondrules are 50–100× relative to Solar abundance and from anhydrous to ~0.6× the water ice content of dust of CI composition, respectively. Mg#’s and Δ17O values of the type II chondrules suggest higher : (IIB: ~300×, IIA: ~2000×) dust enrichment factors and water ice contents (1–4× the amount of water ice of dust of CI composition). The error bars for Mg#’s represent the range (min-max); for host (mean) Δ17O values, error bars are propagated uncertainties (see Tab. 1).