Radiometric dating geology
In a way this field, called geochronology, is some of the purest detective work earth scientists do.
There are two basic approaches: relative age dating, and absolute age dating.
If we dated a number of individual grains in the sedimentary rock, we would likely get a range of different dates, all older than the age of the rock.
Feldspar does not have any argon in it when it forms.
C) can be applied to many geological materials, including sediments and sedimentary rocks, but the materials in question must be younger than 60 ka.
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.