Why are there gravel beaches? In thousands of years of waves crashing on the beach shouldn’t all the gravel have become sand?

Question

Why are there gravel beaches? In thousands of years of waves crashing on the beach shouldn’t all the gravel have become sand?

In: 6381

Answer 1

Sand on beaches comes mainly from shells of marine animals, not from the soil. As a side note, the sand in the deserts is different than the beach sand in that respect.

Those pebbles on the beach are coming from the soil that gets eroded and washed in the sea. They are pretty “young”, since revealed by the water, maybe just a few years/decades.

Rocks in the soil cannot be carried by waves with the same speed as dirt, so they remain behind for a while. Washed and rounded off…