Radiochemical dating definition chemistry
Using an annual average of the carbon intake over a growing season can account for much food chain lag and produce a usable curve (Figure 1).
Caution must be exercised when dating an elevated sample since the pulse is double valued.
It is relatively easy to achieve 0.5-0.8% precision when analyzing recent full-sized samples.
However, it has been confirmed that atmospheric C concentration with the date.
C has not actually disappeared, it has simply moved out of the atmosphere.
The temporal variations of artificially high levels of atmospheric radiocarbon have been captured in organic material world-wide and thus offer an opportunity to determine a date of synthesis for biomolecules.
The atmospheric concentration of C becomes the fingerprint of this radioisotope in a given year's food supply.
Herbivores lag the atmosphere slightly because their primary carbon source is on the order of months old.
Placing a sample on the ascending or descending side of the pulse can often be accomplished if other information is available.
The precision of bomb-pulse dating depends on the ability to measure the C concentration in a sample and the slope of the curve.
Since radiocarbon is incorporated into all living things, this pulse is an isotopic chronometer of the past half-century.
The atmospheric curve depicted in Figure 1 is a northern hemisphere annual growing season average.
The isotopic content of new plant growth reflects the atmospheric radiocarbon concentration.
New leaves are produced in weeks while larger fruit and vegetables form over the period of a month or two.