greywacke

British  

/ ˈɡreɪˌwækə /

noun

1. any dark sandstone or grit having a matrix of clay minerals

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Etymology

Origin of greywacke

C19: partial translation of German Grauwacke; see _wacke

Example Sentences

Further research revealed that Mr. Greer had worked as a laborer at the fort, and that the slab on his grave was made from greywacke, the same material used in its construction.

From New York Times • May 5, 2023

Another name for a lithic wacke is greywacke.

From Textbooks • Jan. 1, 2015

Angular fragments of Lydian stone, scattered along the valleys, seemed to indicate that the transition schist is the basis of the strata of greywacke.

From Personal Narrative of Travels to the Equinoctial Regions of America, During the Year 1799-1804 — Volume 1 by Ross, Thomasina

The date assigned to its upheaval is "after the unfossiliferous greywacke, or Cambrian strata, and before the Silurian."

From Principles of Geology or, The Modern Changes of the Earth and its Inhabitants Considered as Illustrative of Geology by Lyell, Charles, Sir

Shales and conglomer-  ate of Burnot with  quartzite, of Bierl�  and red slates of  Vireux, greywacke  of Vireux, greywacke  of Montigny, sand-  stone of Anor.

From Encyclopaedia Britannica, 11th Edition, Volume 8, Slice 3 "Destructors" to "Diameter" by Various