Why is it that some beaches are sandy and some consist of pebbles?

Question

Is it simply to do with what's on the ocean/sea floor?

Answer 1

A lot of beach material comes from rivers that empty into ocean near by. Sand grains and pebbles are products of erosion. They are formed in and are washed down to the mouths of rivers and then carried along the coast by ocean currents and wind. What ever is on a beach at a particular time is the result of a balance of forces, wind, waves, currents. Under some circumstances the sand may be washed out to sea leaving the pebbles behind. Sometimes a single severe storm will wash out a beach that has taken 100s of years to build.

There are other ways that beaches form. In desert areas the sand on the beach may be desert sand blown there by the wind.

Answer 2

Good question. I always thought that, at the dawn of time...all beaches were pebbly and the sand came from the pebbles being washed against each other by the sea.
But, as you say, some beaches....like Brighton and most of the south coast, remain pebbly. I will watch this question with great interest. I hope somebody can tell us !!

Answer 3

It's because the waves are stronger at the places with sand!