Let us imagine that the date reported by the lab was 150.7 ± 2.8 million years.
Our geologist would be very happy with this result.
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.
And, of course, the reported error ignores the huge uncertainties in the Creationist physicists point to several lines of evidence that decay rates have been faster in the past, and propose a pulse of accelerated decay during Creation Week, and possibly a smaller pulse during the Flood year. He may suggest that some of the chemicals in the rock had been disturbed by groundwater or weathering.
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.
It is clear that the sedimentary rock was deposited and folded before the dyke was squeezed into place.
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.
Would he have concluded that the fossil date for the sediments was wrong? Would he have thought that the radiometric dating method was flawed? Instead of questioning the method, he would say that the radiometric date was not recording the time that the rock solidified.
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.
He may suggest that some other very old material had contaminated the lava as it passed through the earth.
Or he may suggest that the result was due to a characteristic of the lava—that the dyke had inherited an old ‘age’. 200.4 ± 3.2 million years) implies that the calculated date of 200.4 million years is accurate to plus or minus 3.2 million years.
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.
They would all have fitted nicely into the field relationships that he had observed and his interpretation of them.
It relates only to the accuracy of the measuring equipment in the laboratory.