Radioactive dating rocks and fossils
The time scale is refined to reflect the relatively few and progressively smaller inconsistencies that are found.This is not circularity, it is the normal scientific process of refining one’s understanding with new data. If an inconsistent data point is found, geologists ask the question: “Is this date wrong, or is it saying the current geological time scale is wrong?In addition to the ages of Earth, Moon, and meteorites, radiometric dating has been used to determine ages of fossils, including early man, timing of glaciations, ages of mineral deposits, recurrence rates of earthquakes and volcanic eruptions, the history of reversals of Earth's magnetic field, and the age and duration of a wide variety of other geological events and processes.Understand how decay and half life work to enable radiometric dating.
These radioactive elements constitute independent clocks that allow geologists to determine the age of the rocks in which they occur.
The number of parent atoms originally present is simply the number present now plus the number of daughter atoms formed by the decay, both of which are quantities that can be measured.
Samples for dating are selected carefully to avoid those that are altered, contaminated, or disturbed by later heating or chemical events.
by Andrew Mac Rae Radioactive dating of rocks and fossils is often misunderstood, even by some scientists.
It is not a circular process, and leads to ever-more-reliable data, supported from a number of different avenues.
As radioactive Parent atoms decay to stable daughter atoms (as uranium decays to lead) each disintegration results in one more atom of the daughter than was initially present and one less atom of the parent.