Here is some advice from a geologist
the supper continent Pangea did not have an inland sea when the contents shifted and north and South America separated over millions of years there was hydro carbon materials deposited ..that is why the orange basis off shore Namibia and of shore Surinam and Guyana are the places to invest your oil money for a good explanation of how it. Works watch the Dec 11 presentation from the cgx website its about a hour long but shows how deposits form ..good luck