Fossil radiometric dating
Fossils document the order of appearance of groups and they tell us about some of the amazing plants and animals that died out long ago.
Fossils can also show us how major crises, such as mass extinctions, happened, and how life recovered after them.
Since then, geologists have made many tens of thousands of radiometric age determinations, and they have refined the earlier estimates.Results from different techniques, often measured in rival labs, continually confirm each other.Every few years, new geologic time scales are published, providing the latest dates for major time lines.Accurate dates also allow us to create sequences of evolutionary change and work out when species appeared or became extinct. These are: Where possible, several different methods are used and each method is repeated to confirm the results obtained and improve accuracy.Different methods have their own limitations, especially with regard to the age range they can measure and the substances they can date.