Despite the age of current seafloor rocks, what evidence suggests that the oceans once existed billions of years ago?

To help answer the critical thinking questions below, review your chapter reading and assignments 2 and 3 and watch the following video from the Earth Revealed series at the following website:

http://www.learner.org/vod/vod_window.html?pid=315 (Links to an external site.)

Once you click on this link, scroll down to Series No. 4, The Sea Floor and click on the icon  to play the short video.

Question: 

1. Despite the age of current seafloor rocks, what evidence suggests that the oceans once existed billions of years ago?

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