How is it possible for sandstone derived from sediment deposited in a beach environment to comprise a formation that blankets a broad region?

When you consider that the world wide flood covered the entire earth, it was depositing similar sediment over a giant area. Later erosion cut through these layers of sediment, thus fragmenting them across the globe.

Water flows along the east coast and across the western tropical pacific towards south america, while they both are directed towards that way,  el niño does not directly affect the southern flow of water along the coast. 

Answer sinking and cooled;