"WACKE"@en . . . . "stable"@en . . . . "Wacke"@en . . . "Wacke - A type of silicate-sandstone. In the Rock Classification Scheme, wackes have 15 - 75% matrix. British Geological Survey Research Report RR/99/03, section 2.2 and fig. 3."@en . . . "Wacke"@en . . . . .