Radiometric dating allows us to determine international dating sites russia
The technique can, however, provide the relative ages of bones from the same site.
Most fossils are found in sedimentary rocks deposited in layers.
The heat from a volcanic eruption releases all the argon from the molten rock and disperses it into the atmosphere.
Argon then starts to re-accumulate at a constant rate in the newly formed rock that is created after the eruption.
Knowing when a dinosaur or other animal lived is important because it helps us place them on the evolutionary family tree.
In special cases, bones can be compared by measuring chemicals within them.
This relatively new technique was developed in order to achieve more accurate dates than those obtained from the potassium-argon method.
The older method required two samples for dating and could produce imprecise dates if the argon was not fully extracted.
This damage is in the form of tiny marks called fission tracks.
When volcanic rocks and minerals are formed, they do not contain fission tracks.Where the rocks are not strongly folded or tilted it is possible to work out the order in which the layers were formed.