Methods scientific dating

01 Feb

They said the sample was contaminated with excess argon.

Using new samples of feldspar and pumice they ‘reliably dated’ the tuff at 2.61 million years, which agreed nicely.

Tests by other scientists using paleomagnetism and fission tracks confirmed the lower date.

Then Richard Leakey found a skull (called KNM-ER 1470) the KBS tuff, a skull that looked far too modern to be 3 million years old.

Using the potassium-argon method, Fitch and Miller were the first to measure the age of the tuff.

Their result of 212–230 million years did not agree with the age of the fossils (elephant, pig, ape and tools) so they rejected the date.

So Curtis and others redated the KBS tuff using selected pumice and feldspar samples, and obtained an age of 1.82 million years.

This new date agreed with the appearance of the new skull.