Geochronology: Unraveling the Earth’s Timeline Geology is the study of the Earth’s composition, structure, and history. It is a vast field that encompasses various branches, with one of them being geochronology. As an expert in geology, I will explain to you the complexity and significance of this field in a concise and clear manner. Geochronology is the science that deals with understanding and determining the ages of rocks, sediments, and other geological materials.