Principle of relative dating
Unstable isotopes decay to a more stable configuration.
The three main types of decay used for radiometric dating are: The half-life of an isotope is the amount of time it takes for one-half of the atoms in a sample to decay—which remains constant for each unique sample.
Drag and drop the correct descriptions for the order of events conveyed in the accompanying diagram. Which of the following statements about Faults A and B is correct?
A fault (F) breaks three layers of sedimentary rock (S).
Although some isotopes are stable, others are unstable because the forces binding protons and neutrons together are not so strong.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.This matching process is called correlation, which has been an important process in constructing geological timescales.Some fossils, called index fossils, are particularly useful in correlating rocks.For a fossil to be a good index fossil, it needs to have lived during one specific time period, be easy to identify and have been abundant and found in many places. If you find ammonites in a rock in the South Island and also in a rock in the North Island, you can say that both rocks are Mesozoic.