Once the worth of index fossils had been established on the basis of stratification studies, they could logically be used to extend the correlation of rock formations to other continents.At this point in time they were simply a useful tool for correlating rock formations.Your chances are 6.2 billion to one of getting the right order for all thirteen.And, when you consider that each period can also be divided into "upper, middle, and lower," the odds of arranging them in the correct order by pure chance become astronomical. It has correctly placed the Cambrian between the Precambrian and the Ordovician, the Ordovician between the Cambrian and the Silurian, the Silurian between the Ordovician and the Devonian, and so forth.One would think that the flood sediments (gathered from the four corners of the old antediluvian world) and their associated igneous rock (formed during the flood) would all register very little radiometric age.
In some parts of the world the Cretaceous is found deeper than is the Cambrian in other parts of the world.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.What does the Jurassic strata have that the Tertiary strata do not? Neutrinos penetrate the earth so easily that they would affect all strata more or less equally, to the extent that they affect anything at all.If rock type mattered then we would expect a zircon crystal's lead content to vary dramatically within the Cambrian or Cretaceous strata according to their local rock types. Cosmic rays, on the other hand, don't penetrate that far into the earth to begin with, so we can rule them out.