wacke Geol.
(ˈwækə)
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 tr. Pallas' Trav. II. 115 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, hornslate, 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. |