The Appalachian Mountains as the "Wreck of the World"

The great Appalachian Mountains, which run from York River back of these Colonies to the Bay of Mexico, show in many Places near the highest Parts of them, Strata of Sea Shells, in some Places the Marks of them are in the solid Rocks. 'Tis certainly the Wreck of a World we live on! [...] Such changes in the superficial parts of the globe seemed to me unlikely to happen, if the earth were solid to the centre. I therefore imagined, that the internal parts might be a fluid more dense, and of g...