Radiometric dating geology
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.Each half-life is 1.3 billion years, so after 3.9 billion years (three half-lives) 12.5% of the original 40K will remain.One good example is granite, which normally has some potassium feldspar (Figure 8.15).
Fragments of wood incorporated into young sediments are good candidates for carbon dating, and this technique has been used widely in studies involving late Pleistocene glaciers and glacial sediments. Pretty obvious that the dike came after the rocks it cuts through, right?With absolute age dating, you get a real age in actual years.The red-blue bars represent 40K and the green-yellow bars represent 40Ar.[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.