Radioactive dating equation
Consequently, at any given time the % of parent atoms which decay is constant.In other words, radioactive decay is a Constant Rate Process.Subsequent disintegration will produce daughter atoms replacing the original radioactive parents.Consequently, the process of cooling and crystallization starts the clock for igneous rocks.The solution is: The equation above is known as the decay equation.It shows that at any time t, the number of parent atoms, N, is equal to the number of original parent atoms at time zero (N The decay equation shown above constitutes the basis for determining the absolute ages of appropriate rocks and/or minerals.
Consequently, a sedimentary rock such as a sandstone or a shale is likely to consist of framgents of different age.Radiometric dating of sedimentary rocks is, therefore, not common. : These rocks typically form in deep levels of the crust, and consist of minerals that have formed in response to increasing temperature and pressure.If a new mineral grows in a metamorphic rock, and if that mineral incorporates radioactive isotopes in its crystal structure, then dating of that mineral can provide an estimate of the time of mineral growth (metamorphism).The simplified application of the decay equation presented above, bases age determinations on measurement of the ratio of parent : daughter isotopes.The fundamental assumption in this simplified approach is that there existed no daughter atoms at the time the radiometric clock started.
As an example, consider Carbon: All atoms of Carbon consist of 6 protons and 6 electrons.