Oldest radiocarbon dating
They serve as ‘guiding fossils’ for dating (yes, early archaeologists borrowed this term from geology).
At Göbekli Tepe, we can differentiate two layers which are completely different in the type of architecture appearing in them.
The other factor is what has become known as the "radiocarbon barrier" at around 55,000–60,000 years.
The older beta counting instrument was stretched to get results of 50,000 years, whereas the AMS instrument should be effective up to 95,000 years.
Muhammad is generally believed to have lived between 570 A. The two sheets of Islam's holy book were discovered in a library at the University of Birmingham in England, where they had been mistakenly bound in a Koran dating to the seventh century.