Fig. 16
From: Infiltration metasomatism of the Allende coarse-grained calcium-aluminum-rich inclusions
Phase boundaries of reactions involving either aqueous (top panel) or gaseous (lower panel) silica. The lack of analcime among alteration products places an upper limit on XH4SiO4 or XSiO2 in steam and aqueous solution, respectively. In the lower panel, the “condensed steam” field designates an aqueous solution formed by in situ condensation of steam as opposed to the “external” aqueous solution, which comes to a CAI from outside (matrix?) as a liquid