High CO_2 solubilities in mantle magmas: Comment and reply

Abstract

The two "arguments" discussed in the comment by Eggler and others exclude direct reference to what we consider to be the three main conclusions of the paper by Wyllie and Huang (1976). These conclusions should clarify the points made by Eggler and others; in fact, we have large areas of agreement. We agree on the following two points for systems such as CaO-MgO-SiO_2-CO_2: 1. For a liquid of fixed oxide/SiO_2 ratio, the CO_2 solubility increases progressively with increasing pressure. For compositions similar to common silicate magmas, the CO_2 solubility remains below 5 to 8 percent up to 30 kb. 2. At fixed pressure, the CO_2 solubility increases from SiO_2 to the oxide or oxides, with maximum values at 30 kb near 45 percent for the oxides (molten carbonates).

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