WOW -- you can't see the forest for the trees, can you?
Please set your college books aside and try and formulate a mental picture of what I'm saying here.
The Flood waters are GONE -- sharks, whales, people, seaweed, coccoliths, etc. and so forth are stretched from one end of Pangaea (China?) to the other (New Jersey?) and everywhere in-between.
Lying in [what is now] China, the Sahara Desert, Nebraska, Mt. Ararat, Mexico, etc. -- not to mention in the oceans, themselves.
Walk 10 feet and there's a T. Rex carcass, walk another 10 feet and there's a shark, walk another 10 feet and there's a man...
Now, God comes along and "sweeps" up the coccoliths from one end of this supercontinent to the other and stockpiles them in Dover.