Dating fossils through strata and radiometric samples
The half-life of uranium-238, for example, is 4.5 billion years.By measuring the concentration of uranium-238 in comparison with the products of its decay (especially lead-206), a scientist can estimate the age of the rock in which the uranium was found.
Over time, the Ar remain embedded within the crystal, unless the rock is subjected to high temperatures after it forms.
One of the isotope pairs widely used in geology is the decay of K is a radioactive isotope of potassium that is present in very small amounts in all minerals that have potassium in them.
It has a half-life of 1.3 billion years, meaning that over a period of 1.3 Ga one-half of the Figure 8.14 The decay of 40K over time.
[SE] K-Ar is just one of many isotope-pairs that are useful for dating geological materials.
Some of the other important pairs are listed in Table 8.2, along with the age ranges that they apply to and some comments on their applications.
Search for dating fossils through strata and radiometric samples:
[SE] In order to use the K-Ar dating technique, we need to have an igneous or metamorphic rock that includes a potassium-bearing mineral.