Geological time scale: The Geological Time Scale is

The Geological Time Scale is the system used by geologists, paleontologists, and other Earth scientists to talk about the timing and relationships among events that took place during Earth's history. It breaks down an enormous amount of time since Earth formed some 4.567 billion years ago into a workable framework. The time scale is divided into several subunits namely eons, eras, periods, epochs, and ages which represent major stages in the geological and biological evolution of the Earth ... Learn how geologists organize Earth's history into hierarchical units based on rock layers and fossils. Explore the principles, methods, and applications of the Geologic Time Scale, from eons to chrons. The geologic time scale is the stratigraphic history of the Earth. Stratigraphy, also called chronostratigraphy is the ordering and analysis of the layers of the Earth (also called strata) based chronological dating techniques and the layers' positions relative to each other. Geologic time begins approximately 4.6 billion years ago, shortly after when the Earth began to form. [1] The definitive geologic time scale chart is created by the International Commission on Stratigraphy (ICS, see ... Scientists use the geologic time scale to organize Earth's long history into eons, eras, and periods. The Phanerozoic eon is known for the appearance and dominance of complex life like mammals and humans. Each eon, era, and period in the geologic time scale is defined by unique events and life forms.