In one of my Geography books, the following sentence is written:
Though weathering aids erosion, it is not a pre-condition for erosion to take place.
How can I justify this? Almost all the forms of erosion that I know happens on weathered rocks. Do we have any examples of erosion without weathering? As weathering means to strip off or to uncover, and erosion means to transfer.
So far I came up with one example: Blast eruption of volcano makes small stones and pebbles, which could be carried by waves, rivers etc.