The "age of rocks" versus "age of fossils" question is actually kind of interesting, though not in the way Doc so fervently wishes.
Most fossils are marine. When they died, they sank to the bottom, or they were already on the bottom, so the bottom is obviously older than the fossil (though maybe only by hours). The sediments which cover the fossils are younger than the dead critter, though again, probably not much.
But then, the "bottom" of most oceans is quite mucky, so the dead critters may sink a bit into slightly older sediments. Or, the fossils may be of burrowing critters, meaning they penetrate into even older sediments. But really, all of these differences are inconsequential when dating sedimentary rocks. With rare exceptions, they are all within error bars of being contemporary.
However, there are a few things to remember. First of all, the sediments themselves, unless they are newly extruded volcanic ash, were formed by the breakup of older rocks, so the time of their crystallization may have been a long long time before the became sediment. If you date the sediment particles, they will probably be significantly older than the dead critter.
Secondly, note that sediment is not rock. True, limestone, especially coral, may be a "rock" as soon as it is formed, but this is the exception rather than the rule. These "instant preservation" fossils are some of the highest quality fossils in existence, but they are not as common as other types. For most sediments, the lithification and cementation process may occur thousands or millions of years after the deposition. So it is important, when you are taking your sample for radiometric dating, to know whether you are sampling matrix or cement. And you have to know the source of the cement. Was it formed by recrystallization of the local sediments, or was it carried in years later by groundwater moving through the strata?
And we also have to take into account a process called diagenesis, which is the change of the rocks subsequent to burial. Compositions of rocks can change markedly over the millenia, and indeed, many fossils no longer contain any of the original critter, or even the mold of the critter, but have been completely replaced by other minerals. Most of you who like fossils have probably seen these shiny silicate nauteli or petrified trees. I promise you, few were made of silicates when they were alive.
But the people who have made a career of doing radiocarbon dating are generally knowledgable about these "gotchas" and can usually select careful samples and proper error bars to allow for these differences. It is really a shame that fundamentalists will not allow themselves to see the beauty and complexity of this process, rather than trying to fit all the data into their mythology.
