Geochronology is the science of determining the age of rocks, minerals, and geological events. Its main objective is to answer questions such as:
Essentially, geochronology constructs the “timeline” of Earth’s history.
Most geochronological methods are based on radioactive decay. Certain unstable chemical elements (parent isotopes) slowly transform into other elements (daughter isotopes) at a known rate, for example:
By measuring the ratio between these elements, we can calculate how much time has passed since the mineral crystallized.
U–Pb (Uranium–Lead). One of the most accurate methods, it allows for dating events ranging from millions to billions of years. It is primarily used in:
Ar/Ar (Argon–Argon). Widely used in:
Rb–Sr and Sm–Nd. These are used to study:
Carbon-14. Used for recent and organic materials (archaeology, paleontology), not for ancient rocks.