Although the crystalline rocks from Canada and some of the more resistant stratified rocks south of the Great Lakes occur as boulders and stones, a great part of the till has been crushed and ground to a clayey texture.
12.
The valleys by which the uplands are here and there trenched to moderate depth appear to be, in part at least, the work of streams that have been superposed upon the peneplain through the now removed cover of stratified rocks.
13.
The hot springs, among which those of Les Escaldes in Andorra, Panticosa and Lles in Spain, Ax-les-Thermes, Bagn�res-de-Luchon and Eaux-Chaudes in France may be mentioned, are sulphurous and mostly situated high, near the contact of the granite with the stratified rocks.
14.
In America, Benjamin Silliman at Yale College spread the concept, and in an 1833 essay dismissed the earlier idea that most stratified rocks had been formed in the Flood, while arguing that surface features showed " wreck and ruin " attributable to " mighty floods and rushing torrents of water ".
