Carbon dating based assumptions
Carbon-14 dating cannot be applied to materials that have no C dates are less than that figure.
It is sometimes thought possible to extend the dating range a few half-lives, so one occasionally sees dates as old as 70,000 years or more.
C in coal and oil is much less than in the present environment. This gives a ratio of 300:1 for pre-Flood biosphere carbon to present biosphere carbon.
Surprisingly, in at least one case the date range given by There may be other examples of systematic variation in isotope decay rates.The geophysical reservoirs include the atmosphere, the oceans, the biosphere, and the sediments.Violations of this assumption occur in the ocean reservoir due to the time required for mixing of surface waters with the deep layers. Content Header .feed_item_answer_user.js-wf-loaded . John Woodmorappe’s books are advertised elsewhere on my web site.
It is widely used in dating fossils or archaeological samples containing organic material such as wood, charcoal, bone, shells, etc.