Sedimentary rock age dating Live sex chat no regstry
But, how can we determine how old a rock formation is, if it hasn’t previously been dated?
Scientists can use certain types of fossils referred to as index fossils to assist in relative dating via correlation.
For example if you have a fossil trilobite and it was found in the Wheeler Formation.
The Wheeler Formation has been previously dated to approximately 507 million year old, so we know the trilobite is also about 507 million years old.
Index fossils are fossils that are known to only occur within a very specific age range.
Relative dating is used to arrange geological events, and the rocks they leave behind, in a sequence.
Relative dating does not provide actual numerical dates for the rocks.
They use absolute dating methods, sometimes called numerical dating, to give rocks an actual date, or date range, in number of years.
This is different to relative dating, which only puts geological events in time Most absolute dates for rocks are obtained with radiometric methods.
Many of these organisms have left their remains as fossils in sedimentary rocks.
Geologists have studied the order in which fossils appeared and disappeared through time and rocks. Fossils can help to match rocks of the same age, even when you find those rocks a long way apart.