I pointed you to Wikipedia because it is easy to access and has references you can check if you want to, but of course you won’t want to as it contradicts your belief. And at least Wikipedia does have references unlike you.
Does your accurate calculations include the fact that the young mountains are still growing?
Do you just make up this stuff? The record of the earth’s magnetic field is recorded in igneous rocks not sedimentary rocks. Do you know the difference? See Wikipedia if you want the real explanation.