Schematic showing development of the meulière facies. Dissolution of residual limestone patches (1) generated at first a cellular facies (2). There are two subsequent evolution paths. In the upper part of the profile (3), the silica framework inherited from the silicified limestone was progressively dissolved, voids enlarged, and illuviated clay infiltrated some hollows. In the lower part of the profile (4), secondary euhedral quartz was precipitated in the voids. Adapted from Thiry (1999).