What is radioactive dating of rocks Robert shedd s adult dating profile massachusetts
Many people, including many scientists, accept these dates as absolute truth.They believe that when different radio-dating methods are used on the same rocks, they will all yield the same age.This means that the laboratory testing was precise.However, as the results show, the error estimates say nothing about the accuracy of the ‘ages’ of the rock samples.It seems they are trying to avoid the inescapable conclusion that the radioisotope methods simply do not yield reliable ages. potassium-argon (K-Ar) ‘ages’ calculated for each of the 27 amphibolite samples from Grand Canyon ranged from 405.1 ± 10 Ma (million years) to 2,574.2 ± 73 Ma.That is a six-fold difference, for samples that should be of similar age.
The best isochron plots are where the straight line of best-fit falls within the analytical errors (the ± values) for each data point.
In spite of this, the three different radioisotope methods give three very different ‘ages’—that is the ‘isochron discordance’ is pronounced. For example, if accelerated radioisotope decay occurred, then alpha-decaying radioisotopes would yield older isochron ‘ages’ than beta-decaying radioisotopes.
Figure 8 graphically illustrates how that, even when the calculated error margins are taken into account, the different radioisotope dating methods yield vastly different ‘ages’ that cannot be reconciled. This is exactly the pattern in the Brahma amphibolites in Grand Canyon (figure 8).
For example, the calculated ‘age’ could be taken as the ‘date’ of metamorphism, or it could be the ‘age’ of the original volcanic (or sedimentary) rock, or something in between, or something else.
dating method turned out to be vastly different (see box, ‘Calculating the ages’, below), even for those closely spaced samples from the same outcrop of the same lava flow.