He thinks that the levels of the valleys are at present being raised owing to the deposit of detritus in them. The plains watered by the rivers are one vast sheet of gravel, the streams having changed their courses again and again, so as to flow in turn over every part of these alluvial tracts. The thickness of detritus brought down by the rivers gradually increases towards their mouths.
Archibald Geikie in "The Founders of Geology" describing Guettard's work on the river basins of France. Jean Etienne Guettard lived from 1715-1786, and is for Geikie one of the great unsung founders of geology. This is a tag from Lucy.
1 comment:
Thank you, that was a really interesting one!
Good job you said what it was as I probably wouldn't have guessed...
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