Geol. Also 9 wacca, wake, wacké. [a. Ger. wacke, dial. wake (MHG. wacke large stone, OHG. waggo pebble), a miners’ word, adopted by Werner as a geological term.] A sandstone-like rock, resulting from the decomposition of basaltic rocks in situ. Cf. GRAUWACKE, GREYWACKE.
1803. trans. Pallas’ Trav., II. 175. The calcareous rock above described … sometimes also occurs under the form of Wacca, which is again composed of gritty fragments, caused by the destructive effects of past ages.
1811. Pinkerton, Petral., I. 171. Two [German] papers … ‘On argillaceous schistus, horn-slate, and on wake.’
1816. P. Cleaveland, Min., 284. Basalt often forms one member of a series, beginning with gravel, sand, and clay; this clay gradually becomes less sandy and harder, till it passes into wacke, and the wacke is by insensible degrees lost in Basalt.
1839. Murchison, Silurian Syst., I. xxxvi. 499. The chief portion of the hill consists of a dull rotten wacke.
