A common problem with any dating method is that a sample may be contaminated with older or younger material and give a false age.This problem is now reduced by the careful collection of samples, rigorous crosschecking and the use of newer techniques that can date minute samples.Measuring the proportions of argon-39 and argon-40 within a sample allows the age of the sample to be determined.
Although palynology and micropaleontology are primarily used for the correlation of strata, new and innovative tools such as phytoliths are being developed.Despite the use of geological models and 3D seismics in the exploration and production of oil and gas, biostratigraphic control is still necessary.These include radiometric dating of volcanic layers above or below the fossils or by comparisons to similar rocks and fossils of known ages.Knowing when a dinosaur or other animal lived is important because it helps us place them on the evolutionary family tree.The Palynomorph Eco Group (PEG) model and the Automated Palynodebris Analysis (APA) technique have been developed to recognize subtle but synchronous paleoenvironmental changes that would otherwise remain unnoticed.
Both these tools have been successfully employed for various customers.
It is possible to calculate the age of a sample by measuring the uranium content and the density of the fission tracks.
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.
It is initially formed in the molten rock that lies beneath the Earth’s crust.
The heat from a volcanic eruption releases all the argon from the molten rock and disperses it into the atmosphere.
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.