To establish the age of a rock or a fossil, researchers use some type of clock to determine the date it was formed. Geologists commonly use radiometric dating methods, based on the natural radioactive decay of certain elements such as potassium and carbon, as reliable clocks to date ancient events.

Which method of dating rocks uses sedimentary rock?

Radiocarbon dating Radiocarbon dating can be used on sediments or sedimentary rocks that contain carbon, but it cannot be used on materials older than about 60 ka. Assume that a feldspar crystal from the granite shown in Figure 8.15 was analyzed for 40K and 40Ar. The proportion of 40K remaining is 0.91.

Can all rocks be dated with radiometric methods?

Of the three basic rock types, igneous rocks are most suited for radiometric dating. Metamorphic rocks may also be radiometrically dated. However, radiometric dating generally yields the age of metamorphism, not the age of the original rock.