jan 1, 1960 - Harry H. Hess, Robert Dietz

Description:

Found samples of the basaltic oceanic crust overlying sediment over time became younger and thinner. Rock making up the oceanic floor was found to be much younger than continents, no samples of the oceanic floor being over 200 million years old have been found to date. While the oceanic crust is no more than only 200 million years old, the continents are over 3 billion years old.

Found at https://docs.google.com/document/d/14PxVK4jfuRRsDHaN0j6CjiE-IA9YmKOWZJ9ArQgb-3s/edit

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