Dating rocks and soils
When these fossils exist, they can be used to determine the age of the strata, because the fossils show that the strata correspond to strata that have already been dated by other means.
However, local eruptions of volcanoes or other events that give off large amounts of carbon dioxide can reduce local concentrations of carbon-14 and give inaccurate dates.The level of bomb carbon was about 100% above normal levels between 19.The level of bomb carbon in the northern hemisphere reached a peak in 1963, and in the southern hemisphere around 1965.These effects are corrected for by the calibration of the radiocarbon dating scale. Nuclear carbon dating is not the only test used to date fossils.
Search for dating rocks and soils:
Carbon-14, though, is continuously created through collisions of neutrons generated by cosmic rays with nitrogen in the upper atmosphere and thus remains at a near-constant level on Earth.