jan 1, 1960 - Harry Hess
Description:
Harry Hess proposed the idea that when the seafloor was made at mid-ocean ridges, it spread into sperate directions. First of all, deep ocean floor samples were used to show that the closer you got to the mid-ocean ridge, the younger the ocean crust and sediment. And the cover of sediment is not as thick by the ridge. Also, the ocean floor's rock is reasonably younger than the continental rocks. This shows that the ocean's older crust was forced back under in ocean trenches. This relates to tectonic plates because sea-floor spreading explains how the plates move.-Source 5
Added to timeline:
Date:
jan 1, 1960
Now
~ 65 years ago