Sandstone, limestone, dolomite, shale, chert, salt, conglomerate, coal and other rock types are not diagnostic of specific strata systems.
Therefore, a rock's physical appearance cannot, with certainty, distinguish the system or strata level to which a rock may belong.
You can learn more about fossils, dinosaurs, radiometric dating and related topics by reading through the links on the next page.
Radiometric dating isn't the only method of determining the age of rocks.
In addition, the oldest known moon rocks are 4.5 billion years old.