Radiocarbon dating alternatives - The method - radiocarbon WEB-info


Plants and animals assimilate carbon 14 from carbon dioxide throughout their lifetimes. When they die, they stop exchanging carbon with the biosphere and their carbon 14 content then starts to decrease at a rate determined by the law of radioactive decay.

Because the radiocarbon to stable carbon ratio in the atmosphere has fluctuated over time, there are "wiggles" in the calibration curve. Thus it is possible in some instances for two samples from a few decades apart to have the same radiocarbon concentration today, and hence the same apparent radiocarbon age. This happens whenever there is a wiggle in the curve at the time the samples died. This, in fact, is the most significant factor contributing to loss of precision in radiocarbon dates today. However, this contribution is usually only a few decades.

However, there is actually no empirical evidence to back the claim that varves form as annual deposits over extended periods of time. There are some varve pairs that form in a single year, but in many cases, the observational evidence shows that multiple supposed varve couplets can and have formed in a single year (Buchheim and Biaggi 1988; Lambert and Hsü 1979; Makse et al. 1997). In fact, it has been documented that at least five pairs of varve couplets can form in a single year due to fluctuations in water flow (Lambert and Hsü 1979). It appears then, that claiming a varve is an annual event is an assumption in itself; one steeped in uniformitarian thought, but not reality.


Radiocarbon dating alternatives

Radiocarbon dating alternatives