Dating fossils ppt
Fossils and other objects that accumulate between these eruptions lie between two different layers of volcanic ash and rock.
Measuring the proportions of argon-39 and argon-40 within a sample allows the age of the sample to be determined.
This problem is now reduced by the careful collection of samples, rigorous crosschecking and the use of newer techniques that can date minute samples.
Volcanic rocks – such as tuff and basalt – can be used in dating because they are formed at a particular moment in time, during an eruption.
The age of volcanic rocks and ash can be determined by measuring the proportions of argon (in the form of argon-40) and radioactive potassium within them.
Each volcanic eruption produces a new deposit of ash and rock.
The heat from a volcanic eruption releases all the argon from the molten rock and disperses it into the atmosphere.