Suppose you find a fossil at one place that cannot be dated using absolute methods.That fossil species may have been dated somewhere else, so you can match them and say that your fossil has a similar age.
Scientists use carbon dating to determine the age of a rock.
Organic material from the rock is tested to determine the ratio of two different types of carbon, and use that information to calculate the estimated age.
Scientists can't exactly determine the age of a rock but they can determine which layer is oldest and youngest, and then try to determine the age of the ones in the middle off of the basic observation.
A half-life is half of the time it takes for a radioactive atom to decay, and it helps in determining the absolute age of a rock because if you know its half-life, you can multiply it by two to get its actual or absolute age.
Throughout the history of life, different organisms have appeared, flourished and become extinct.
Many of these organisms have left their remains as fossils in sedimentary rocks.Relative dating is used to arrange geological events, and the rocks they leave behind, in a sequence.The method of reading the order is called stratigraphy (layers of rock are called strata).It is difficult to determine the absolute age of a sedimentary rock because sedimentary rocks are made up of diverse particles that are all different ages.As a result radioactive dating can only determine the age of the particles, not the whole rock.Students begin by observing a photograph and a diagram of rock layers near Whanganui, watch an animation about how the layers were formed, then use an interactive labelling diagram to work out the order in which the rocks were created.