Charles Darwin,
Journal of Researches
(1860)
“ Every one must have remarked how mud-banks, left by the retiring tide, imitate in miniature a country with hill and dale; and here we have the original model in rock, formed as the continent rose during the secular retirement of the ocean, instead of during the ebbing and flowing of the tides. If a shower of rain falls on the mud-bank, when left dry, it deepens the already-formed shallow lines of excavation; and so is it with the rain of successive centuries on the bank of rock and soil, which we call a continent. ”
