Interesting. Fossils are one of the strongest supports for Young Earth creation. And there are serious hurdles for those promoting the evolutionary 'geologic column.' Sorry this won;t be more in-depth but I don't have a lot of time for a long answer:
1. The 'geologic column' is a diagram, not a reality. It isn't found 'complete' as diagrammed anywhere in the world. There are a handful of places where all 'ten' stacks have been assigned/inferred, but even here it is not complete as none of those ten layers is the necessary thickness for the diagrammed column, even when taking erosion into account. For example, the diagram represents about 100-200 miles of rock. But local, real-world formations taken as 'proof' of the column are rarely more than a mile in total. Even the famous 'North Dakota' stack of ten is at most 16 miles. Erosion or any other known way to chip at those sediments just can't explain such a huge gap - this is a giant hurdle for proponents of the geologic 'column'. Furthermore, erosion is one of the worst forms of special-pleading for long-Earth proponents to hold to as in most places around the world there are no signs of erosion between definitive layers (e.g. fossilized soil, wind channels, water channels.)
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And 'ten-stacks' are quite rare (less than .4% of the Earth's surface, at most.) Far more common is 1-3 layers. Layers are often found out of order in a way unexplainable by seismic activity, or are found without their 'intermittent' layers. (When there may well be a stack with the missing layer just a few hundred feet away) - that's a mystery for old-Earth proponents and does not support the geologic column hypothesis.
2. Whoever told you that plants/animals are separated 'correctly' within the layers is misinformed. They often are not. (Plus, for the theory of the geologic column coupled with evolution of the species to be true one would need a near-perfect record, with big deviations having clear explanations as to how they could have occurred.) You may have heard of Index fossils. Why are these particular fossils used to date layers and not others? Because unlike the rest of the fossils which can easily be found in different layers (even straddling two layers, which should be impossible under an Old Earth view unless it's cataclysm driven,) index fossils are 'more commonly' found in the 'expected' locations. But even these are not 100% consistent. For example, flowering plants supposedly evolved ~160 million years ago, but pollen samples are found in Precambrian strata supposedly over 550 million years. And duck fossils, squirrels, bees, platypus, frogs, etc. have been found along with T-Rex fossils. Older fossils can be found in strata above younger ones, or species crossing into strata they are not 'expected' to be in. Sometimes species 'skip' a strata or two as well! [The explanation offered for these many out of place fossils is that they somehow 'slipped' down through solid rock or 'reworked' themselves upwards into the next strata - which doesn't make any geological sense whatsoever.]
http://evolutionfacts.com/Ev-V2/2evlch17e.htm
http://www.creationscience.com/onlinebook/LifeSciences29.html
http://thecreationclub.com/fossils-out-of-time-and-place-bill-nye-should-be-a-creationist-now/
3. Fossilized trees are often found straddling several layers. Not only would this be impossible if sediments represented millions of years, but in many cases the rock surrounding these trees shows signs of being rapidly deposited. (Ironically, the standard explanation of this from an 'old-Earth' perspective is that in these cases, the layers formed very quickly, due to some cataclysm like a volcano, flood, sandstorm, etc.; or for upside down fossilized trees that they somehow got caught standing in water, like a swamp or flood.) Which seems to back up the flood view more than the geologic column.
4. Many creatures still alive today yet dated to 500+ millions of years old (e.g. starfish, jellyfish, brachiopods, clams, and snails) are often 'missing' from the strata they are supposed to be found in or the layer they would have been expected to be found in missing entirely.
5. In many places strata overlies other strata at an angle. These angled layers at any given point are used to support the idea of a 'column.' Why is this a problem? What is found in the layers changes laterally, not just vertically! Imagine three layers angled over each other like roof tiles which appear to match with geologic layers A, B, and C at point X. But travel along some distance and the same exact strata now hold fossils more corresponding to B, C, and D. That isn't a support for the geologic column at all - it actually is what one would expect to find with sediment layering.
6. 'Cope's Rule' details how fossils (in general) are found 'larger' as one goes up through the strata.
https://en.wikipedia.org/wiki/Cope's_rule
There is no basis for this in evolution, nor any reason longer time periods would make fossils bigger as one goes up the strata. This doesn't match with ''living fossils,' many of which are clearly smaller than their ancestors. Rather, this finding matches well with the sorting of water, where smaller organisms would be expected to be deposited first.
