"Percipient, thank you for the answer. What you say it's what I thought until I read the book "Plate Tectonics" by Jon Erickson."
--Yes, Good book
I would also recommend Marine Geology by Jon Erickson, that is if you have not yet read it. It was about my 2 or 3rd Geology related text, like Plate Tectonics it is clearly written and deals mostly with Marine hydrothermals and Sea-floor spreading.
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