by Edward T. Babinski
The story of the geologic column begins with the story of the first map of the geology of England (made during a time of blasting mountainsides and drilling holes through hills when railway lines were being laid down). Certain formations were found to lay above other specific formations. The Relative Order of the formations was found to be the same even in distant locations of Great Britain. In other words such and such a formation was always found above such and such a formation. Or such and such a formation was always found below such and such a formation. Later students of geology added to the numbers of general formations and also discovered distinctions within such formations, but the Relative Order of the formations remained the same, and that is what the geological column that we have today represents, the Relative Order of various known formations. And though that relative order was deduced via visible out-croppings all over the earth (even down to microfossils found in specific formations) it was only fairly recently that geologists have discovered basins that contain representative sediments and fossils common to each major division in the geological column, in the expected relative order. Other parts of the world are known to contain many basins lacking a formation or two or three or four or five. But in such cases that lack representative sediments common to all the major divisions, the Relative Order of the formations Still Remains the same as that based on the earliest observations. In other words erosion is the rule, but the relative order remains as expected for the sediments the remains. Furthermore, when representative samples of all the major epoch are found piled up in thick basins of sediments the relative order fits the geologic column.
Furthermore, this relative order remains true right down to Microfossils and Fossil Fragments. No flood could separate things so perfectly, only eons of time could separate the microfossils and fossil fragments, placing them in a strict relative order found all over the earth (with the exceptions of places of non-flat sediments such as mountain-building regions, but those are the exception, not the rule, especially not the rule of flat basins and ancient flat shorelines).
As for where all the sedimentary rock came from, look at the creation off the Hawaiian islands, which are still being created, the youngest islands being those toward the north I believe (or south, I forget), volcanoes still spewing forth molten lava that hardens into land and even mountains, but those islands are all relatively young compared with the great continent of North America.
On the continents, mountains rose and were worn down, land rose and was worn down, it's called erosion by rain, by microbes and lichen that eat rock, by acids from plant and animal decay, but roots growing in crevices and breaking open rock further, by heat cracking mud and drying out rock, by earthquakes crumbling rock, by wind pushing sand, by streams, by rivers, etc. the process repeating itself again and again over eons of time, which also explains why the average depth of sedimentary rock on land is a mile in thickness.
Interestingly, in the ocean, the average depth of sedimentary rock is much less than that found on land, and the rock at the bottom of the oceans is actually younger than that on the land, dating only back to the Triassic I believe, the youngest rocks in the ocean being those found along the mid-Atlantic ridge which is still spewing forth lava as the continents of American and Africa continue to move away from each other.
The problem for Flood geology is explaining the fact that there is so much more sedimentary rock found on the continents than in the oceans. All you have to do is put a platform inside a jar filled with water and sand, and shake it and see how much of the sane remains on the platform and how much of the sand falls to the bottom of the jar. A Flood would have washed far more sedimentary rock off the land. A Flood would have suspended far more sediments in the oceans, which rose above the land (per the Flood of Noah), and then those sediments would have settled out into the oceans, as well as running off the land along with the retreating waters. In fact there ought to be grand canyons all along the coasts of the continents if Flood geology is true. But there's only one Grand Canyon on the planet, and it's not on the coast!