The graptolite-bearing grauwacke of Banffshire seems to have been the only fossiliferous rock that occurred throughout the extent of this ancient northern basin.
We have observed none here in any considerable degree similar to the grauwacke slate of the transition mountains of New York, or even to that of the Alleghanies.
Mr. Nuttall, in his valuable Journal of Travels into the Arkansa Territory, mentions grauwacke slate as occurring along the Arkansa river near Little Rock, p.
The grauwacke reappears, in a most striking manner, at the Falls of Presque Isle River, where the whole mass of water precipitated from the highlands drops into a vast pot-hole, a hundred feet wide and perhaps twice that depth.
This process also gives origin to grauwackes and the grauwacke slates and the argillites.
Thus on Wollaston Island slate and grauwacke can be distinctly traced passing into feldspathic rocks and greenstones, including iron pyrites and epidote, but still retaining traces of cleavage with the usual strike and dip.
The above list will hopefully give you a few useful examples demonstrating the appropriate usage of "grauwacke" in a variety of sentences. We hope that you will now be able to make sentences using this word.
