Entire world used to be covered by water.
I guess I am not the only one who did not know that. I was recently in Colombia and went to the salt mines. It was explained how the salt mines were formed. Ancient ocean covered it.
But here is a recent article https://www.newscientist.com/article/2130266-early-earth-was-covered-in-a-global-ocean-and-had-no-mountains/
"Earth 4.4 billion years ago was flat and almost entirely covered in water with just a few small islands, new research suggests.
Scientists came to the conclusion after analysing tiny zircon mineral grains from a region of Western Australia containing the oldest rocks ever found.
“The history of the Earth is like a book with its first chapter ripped out with no surviving rocks from the very early period, but we’ve used these trace elements of zircon to build a profile of the world at that time,” says lead researcher Antony Burnham, from the Australian National University.
“Our research indicates there were no mountains and continental collisions during Earth’s first 700 million years or more of existence – it was a much more quiet and dull place,” he says. “There are strong similarities with zircon from the types of rocks that predominated for the following 1.5 billion years, suggesting that it took the Earth a long time to evolve into the planet that we know today.”