(01-01-2013 10:26 PM)Phaedrus Wrote: The first question shows a complete ignorance of even the basic fundamentals of geology. It's like asking, "Well how come parents are always older than their kids?" It's so naive and backwards, from the perspective of someone who actually studied geology in college, that I have trouble thinking on a low enough level to answer him.
Fossils are buried in sediment, which is clay, gravel, sand, and such: the eroded remains of older rocks. Rocks are continually uplifted by geological processes, which form hills, mountains, etc. Rocks are eroded from those formations and are carried downhill and downstream. In some areas the sediment settles out of the water and forms layers of sand, mud, or dirt. This is where fossils form. New sediment comes and settles on top. It doesn't magically tunnel underneath the older sediment which is already deposited. It settles on top. Hence why older rocks are on bottom and newer rocks are on top. This is one of the basic principles of geology.
Now, geological activity can disturb rocks, and things like uplift or orogeny or subduction can disturb the ordering of rocks so that you can find newer rocks below older rocks. But this is usually very obvious to geologists when this has happened, because it involves the expenditure of huge amounts of energy over very long periods of times, and the effects on the rocks are obvious.
Precisely. This what we call Superposition. We also have Original horizontality (sediments are originally horizontal) and lateral continuity (sediments extend for significant geographic stretches). They need a basic intro geology textbook before they start spouting off such ignorant statements.