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.
(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.
Studies done on the European continent soon demonstrated the universal validity of index fossils.
That is, an index fossil corresponded to a very specific point in the geologic column.
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.
Noah's flood might just as easily deposit the same crystal in one place as another. Pressure has nothing to do with it, and zircon crystals all have about the same density as their total lead content is small.