It’s been my beliefs that this is where our oil comes from. Very very deep water enriched with minerals from it’s passage thru the earth crust is cooked and oil is formed. But the thought of these basins are larger than surface water is just too much to believe...
The volume of oceans is 310 million cubic miles
The volume of the earth is 260 billion cubic miles
that is 31/26000 =/ 1/900