Graywacke

1 definition found

From The Collaborative International Dictionary of English v.0.48 [gcide]:

  Graywacke \Gray"wacke`\, n. [G. grauwacke; grau gray + wacke
     wacke. See {Gray}, and {Wacke}, and cf. {Grauwacke}.] (Geol.)
     A conglomerate or grit rock, consisting of rounded pebbles
     and sand firmly united together.
     [1913 Webster]
  


     Note: This term, derived from the grauwacke of German miners,
           was formerly applied in geology to different grits and
           slates of the Silurian series; but it is now seldom
           used.
           [1913 Webster]