It is a system of chronological dating that uses chronostratigraphy (the process of relating strata to time) and geochronology (a scientific branch of geology that aims to determine the age of rocks).

It consists of three eras: The Paleozoic, Mesozoic, and Cenozoic, [105] and is the time when multi-cellular life greatly diversified into almost all the organisms known today. [147] The Paleozoic ("old life") era was the first and longest era of the Phanerozoic eon, lasting from 538.8 to 251.9 Ma. [105]

May 24, 2024 · Here is a brief look at the four periods of the Geologic Time Scale that track the Earth's history: Precambrian, Paleozoic, Mesozoic, and Cenozoic.

Jan 17, 2025 · The geologic time scale is the “calendar” for events in Earth history. It subdivides all time into named units of abstract time called—in descending order of duration— eons, eras, periods, epochs, and ages.

Over its history, Earth has gone through several distinct periods that are divided by shifts in the Earth’s geological composition or major paleontological changes, such as mass extinctions. The history of Earth can be divided into 4 major eons, each of which are divided into their own eras, periods, epochs, and ages.

Archeozoic Era 4500-1500 million years ago. This is the first Era to have geologic record. In this early stage of the earth, the surface changes from molten to rock. The continental plates also formed during this timeline. The atmosphere of the earth is made up of 75% nitrogen & 15% carbon Dioxide. These are known as prokaryotic cells.

Feb 28, 2020 · Eons, eras, and periods are usually separated by a significant geologic event and are unique in their climate, landscape, and biodiversity. The Cenozoic era, for example, is known as the "Age of Mammals."

Jan 11, 2025 · The Geologic Time Scale or Geological Time Scale (GTS) is a chronological framework that organizes Earth’s history into various units based on geological and paleontological evidence. It divides Earth’s 4.6 billion-year history into hierarchical units such as eons, eras, periods, epochs, and ages.

Oct 5, 2021 · Geologic time scale showing the geologic eons, eras, periods, epochs, and associated dates in millions of years ago (MYA). The time scale also shows the onset of major evolutionary and tectonic events affecting the North American continent and the Northern Cordillera (SCAK, south-central Alaska; SEAK, southeast Alaska; NAK, northern Alaska; CAK ...

The geological history of Earth follows the major geological events in Earth's past based on the geologic time scale, a system of chronological measurement based on the study of the planet's rock layers (stratigraphy).