How do ocean floor rocks and sediments provide evidence of seafloor spreading

Answer:First, samples of the deep ocean floor show that basaltic oceanic crust and overlying sediment become progressively younger as the mid-ocean ridge is approached, and the sediment cover is thinner near the ridge.

Explanation:

The features of the seafloor and the patterns of magnetic polarity symmetrically about the mid-ocean ridges were the pieces that Hess needed ... As oceanic crust forms and spreads, moving away from the ridge crest, it pushes the continent away from the ridge axis.