Why is radiocarbon dating only rarely applied in geological work Live six chat cam gerl in monticarlo
C ages from terrestrial plants avoid some problems with other materials.Bulk sediment samples and samples of aquatic plants or animals such as the carbonate shells of clams, snails, and ostracodes may yield ages that are too old because of how carbon was fixed by the organism and the potential for the incorporation of “old” carbon from a water body.Laboratory procedures may not be fully able to remove the contaminants.Perhaps the most vexing problem in some outcrop studies are pervasive tiny rootlets from modern plants.By far the most common numerical ages applied to varve sequences are from radiocarbon (C ages it is still the most accurate calibration data available in most lacustrine environments where glacial varves occur.
In some cases, errors may become obvious as they are sometimes on the order of 10 kyr or more (Miller and Thompson, 1979).
A varve sequence might also have events in it of known calendar age, such as beds from flood events or volcanic ash layers that have historic records associated with them.
The more usual case is when numerical ages (estimates of true calendar ages) based on radiometric or other techniques are applied to varves.
One must also remember that all plant fossils are in some state of decay, which can introduce contaminants.
Most often contamination is the result of younger material added to a sample in a particular field setting.