The depth at which either is found can vary dramatically.
In the Grand Canyon area the Cambrian lies beneath a huge column of strata; in California's Mojave Desert portions of the Cambrian are exposed at the surface.
(See Topic A1 for claims of bad dates.) Creationists, on the other hand, must explain to us how sediment and rock laid down in a mere year can yield such fantastic, orderly differences in radiometric ages.
This poses a fatal problem whether one believes in the accuracy of radiometric dating or not!
Just what is it that a Cambrian stratum has which a Cretaceous stratum lacks?
By then, the relative ages (order) of the geologic column had already been worked out in some detail.
Radiometric dating would later confirm the relative ages of the strata and tie them to absolute dates.
Any kind of object clearly restricted to a specific point in the geologic column would do just fine.
If green dice were found only in the middle Ordovician strata, they would make excellent "index fossils." Evolution should be seen as an explanation of the faunal succession, a succession which was worked out long before evolution dominated the scene.