更多graywacke例句

1. Appropriately pronounced a "secondary graywacke slate," by Mr. Eaton.
2. In the transition graywacke of the south of Scotland, the galena mines of Leadhills occur.
3. Their material, however, is not flint, but either graywacke or a kind of tough slate.
4. Is it primitive, or is it graywacke like Catskill Mountains?
5. I received a specimen of slaty graywacke from Lake Superior.