I can't help but think of Huxley's essay,
"On a Piece of Chalk" from 1868. In it, he uses a rock that everyone is familiar with to drive home some very important points. He discusses just how massive these chalk layers are, and then points out how they were built from the tiniest of creatures. Even in 1868 it was obvious to everyone that these deposits required massive amounts of time, and this was well before radiometric dating made it on to the scene.
Ken Ham is known for simplifying geology to the point of stupidity. He will say that floods produce mud, and what do we see in the geology record? MUD!!!!
As Huxley, Nye, and now RAZD point out so very well, it isn't mud. It is life. That is what creationists can not explain, how you can get a thousand feet of the worlds tiniest sea creatures stacked on top of each other instead of the mud we would expect from a flood.
"No less certain it is that the time during which the countries we now call south-east England, France, Germany, Poland, Russia, Egypt, Arabia, Syria, were more or less completely covered by a deep sea, was of considerable duration. We have already seen that the chalk is, in places, more than a thousand feet thick. I think you will agree with me, that it must have taken some time for the skeletons of animalcules of a hundredth of an inch in diameter to heap up such a mass as that. I have said that throughout the thickness of the chalk the remains of other animals are scattered. These remains are often in the most exquisite state of preservation. The valves of the shell-fishes are commonly adherent; the long spines of some of the sea-urchins, which would be detached by the smallest jar, often remain in their places. In a word, it is certain that these animals have lived and died [21] when the place which they now occupy was the surface of as much of the chalk as had then been deposited; and that each has been covered up by the layer of Globigerina mud, upon which the creatures imbedded a little higher up have, in like manner, lived and died."--Thomas Huxley, "On a Piece of Chalk"
Edited by Taq, : No reason given.
Edited by Taq, : added Huxley quote