[ 'greɪwakə ]
( US graywacke )
■ noun Geology a dark coarse-grained sandstone containing more than 15 per cent clay.
Origin
C18 (as grauwacke ): from Ger. Grauwacke , from grau 'grey' + wacke .
[ 'greɪwakə ]
( US graywacke )
■ noun Geology a dark coarse-grained sandstone containing more than 15 per cent clay.
Origin
C18 (as grauwacke ): from Ger. Grauwacke , from grau 'grey' + wacke .
Concise Oxford English vocab. Сжатый оксфордский словарь английского языка. 2004