Assumptions used in carbon dating fools rush in dating quote
Manning, professor of archaeology at Cornell University and director of the Cornell Tree-Ring Laboratory, is the lead author of "Fluctuating Radiocarbon Offsets Observed in the Southern Levant and Implications for Archaeological Chronology Debates," published in the .
Pre-modern radiocarbon chronologies rely on standardized Northern and Southern Hemisphere calibration curves to obtain calendar dates from organic material.
Recognizing this problem, scientists try to focus on rocks that do not contain the decay product originally.
For example, in uranium-lead dating, they use rocks containing zircon (Zr Si O Zircon and baddeleyite incorporate uranium atoms into their crystalline structure as substitutes for zirconium, but strongly reject lead.
These difficulties are considerable, and are discussed below.
For example, we can measure gamma radiation rates at specific frequencies from distant supernovae and compare this to the rate expected for the mass of the star.
With uranium-lead dating, for example, the process assumes the original proportion of uranium in the sample is known with reasonable accuracy.
One assumption that can be made is that all the lead in the sample was once uranium, but if there was lead there to start with, this assumption is not valid, and any date based on that assumption will be incorrect (too old). In the case of carbon dating, it is not the initial quantity that is important, but the initial ratio of C, but the same principle otherwise applies.
Zircon has a very high closure temperature, is very chemically inert, and is resistant to mechanical weathering.
For these reasons, if a rock strata contains zircon, running a uranium-lead test on a zircon sample will produce a radiometric dating result that is less dependent on the initial quantity problem.