Creationists would generally agree with the above methods and use them in their geological work.From his research, our evolutionary geologist may have discovered that other geologists believe that Sedimentary Rocks A are 200 million years old and Sedimentary Rocks B are 30 million years old.
His geological cross-section may look something like Figure 2.
Clearly, Sedimentary Rocks A were deposited and deformed before the Volcanic Dyke intruded them.
Such an interpretation fits nicely into the range of what he already believes the age to be.
In fact, he would have been equally happy with any date a bit less than 200 million years or a bit more than 30 million years.
By looking at other outcrops in the area, our geologist is able to draw a geological map which records how the rocks are related to each other in the field.
From the mapped field relationships, it is a simple matter to work out a geological cross-section and the relative timing of the geologic events.
What would our geologist think if the date from the lab were less than 30 million years, say 10.1 ± 1.8 million years? Or he may decide that the rock had been affected by a localized heating event—one strong enough to disturb the chemicals, but not strong enough to be visible in the field.
No matter what the radiometric date turned out to be, our geologist would always be able to ‘interpret’ it.
He assumes therefore that Sedimentary Rocks A are the same age as the other rocks in the region, which have already been dated by other geologists.
In the same way, by identifying fossils, he may have related Sedimentary Rocks B with some other rocks.
He may suggest that the rock contained crystals (called xenocrysts) that formed long before the rock solidified and that these crystals gave an older date.