Radiometric dating def
These areas of Precambrian rocks are termed, appropriately, the Angaran Shield is applied to a large stable block bounded by the Lena and Yenisey rivers on the east and west and by the Arctic Ocean and Lake Baikal to the north and south.
The The southern two-thirds of peninsular India, most of the western half of Australia, and the eastern segment of Antarctica are also areas of continental shields.
This is why multiple samples are used in critical age determinations.
But these are relatively small effects -- not something that would increase the apparent age of a rock from 10,000 years to 3.6 billion years as in the case of samples "from outcrops in southwestern Minnesota are believed to represent some of the oldest rocks in North America." Indicator 3: Radiometric dating failed on Hawaiian sample: Many creation scientists state that carbon dating and potassium argon dating methods are faulty.
The one on the bottom was millions of years younger than the one on the top.
This proves that radiometric dating is inaccurate and should not be relied upon." Rebuttal: One wonders whether the "slab of stone" from the bottom of the canyon might have simply fallen from the top within the last few centuries?
It is true that the scientist who measures the sample will often ask the probable age of the rock supplied.