The Goniatites, of the tribe of Ammonites,* a are manifested in the transition chalk, in the graywacke of the devonian periods, and even in the latest silurian formations.
We cannot agree in opinion with some who have considered the graywacke as the substratum of the great secondary formation of the valley of the Mississippi.
In attempting to give a more detailed account of these formations, we might perhaps speak of the graywackeas others have done, as a distinct stratum.
In general the category III provinces are dominated by sediments ascribable to the graywacke suite of Pettijohn (1957).
The site where the obelisk was to stand, namely Graywacke Knoll opposite the Metropolitan Museum of Art in Central Park, had already been selected.
Now, Sin Saxon, you know Graywacke is just the life of the house.
I received a specimen of slaty graywacke from Lake Superior.
Is it primitive, or is it graywacke like Catskill Mountains?
The above list will hopefully give you a few useful examples demonstrating the appropriate usage of "graywacke" in a variety of sentences. We hope that you will now be able to make sentences using this word.
