Journal of Geology & Geophysics
Open Access

Geologic Time Scale

The Geological Time Scale is a system of chronological measurement that relates stratigraphy to time, and is used by geologists and other Earth scientists to describe the timing and relationships between events which occurred throughout Earth's history. The Earth history is divided into two great expanses of time. The Precambrian began when Earth first formed & ended about 570 million years ago. The Phanerozoic Eon began 570 million years ago & continues today.

Geologists have divided Earth's history into a series of time intervals like Eons, Eras, Periods, Epochs. Eons are the largest intervals of geologic time and are hundreds of millions of years in duration.Eons are divided into smaller time intervals known as eras; Phanerozoic is divided into three eras: Cenozoic, Mesozoic and Paleozoic. Eras are subdivided into periods; Paleozoic is subdivided into the Permian, Pennsylvanian, Mississippian, Devonian, Silurian, Ordovician and Cambrian periods. Finer subdivisions of time are possible and the periods of the Cenozoic are frequently subdivided into epochs.

Related Journals of Geological Time Scale

Climatology & Weather Forecasting, Earth Science & Climatic Change, Geotimes, Stratigraphy and Geological Correlation, Geological Time Journal, The Geologic Time Scale