Uranium–lead radiometric dating involves using uranium-235 or uranium-238 to date a substances absolute age. Uranium–lead dating is often performed on the mineral zircon (ZrSiO4), though it can be used on other materials, such as baddeleyite and monazite (see: monazite geochronology).

Why is uranium used in radiometric dating?

Fission track dating Several minerals incorporate tiny amounts of uranium into their structure when they crystallise. Because the radioactive decay occurs at a known rate, the density of fission tracks for the amount of uranium within a mineral grain can be used to determine its age.

Is uranium used in carbon dating?

So no fossils can be dated directly using U 238. Because of the huge differences in the half lives of Carbon 14 and Uranium238 they cannot be used together. Carbon 14 can only be used to date fossils of a very recent age. Uranium 238 can only be used to date volcanic rocks of a very old age.

Why is uranium-238 used for dating rocks?

The more lead the rock contains, the older it is. The long half-life of uranium-238 makes it possible to date only the oldest rocks. Also, the half-life of potassium-40 is only 1.3 billion years, so it can be used to date rocks as young as 50,000 years old.