Geologic time scale - Wikipedia
The geologic time scale or geological time scale (GTS) is a representation of time based on the rock record of Earth. 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).
Geologic time | Periods, Time Scale, & Facts | Britannica
2024年11月19日 · Geologic time, the extensive interval of time occupied by the geologic history of Earth. Formal geologic time begins with the Archean Eon (4.0 billion to 2.5 billion years ago) and continues to the present day. Modern geologic time scales also include the Hadean Eon (4.6 billion to 4.0 billion years ago).
Geologic Time Scale: A List of Eons, Eras, and Periods - ThoughtCo
2020年2月28日 · The geologic time scale is a system used by scientists to describe Earth's history in terms of major geological or paleontological events (such as the formation of a new rock layer or the appearance or demise of certain lifeforms).
The Four Eras of the Geologic Time Scale - ThoughtCo
2024年5月24日 · 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.
Geologic Time Scale - Geology (U.S. National Park Service)
2021年10月5日 · 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 ...
Geologic Time Scale - Major Divisions of Geologic Time Chart
Effective communication in the geosciences requires consistent uses of stratigraphic nomenclature, especially divisions of geologic time. A geologic time scale is composed of standard stratigraphic divisions based on rock sequences and …
Geologic Time Scale : Divisions, Periods and Eons - Geology Science
2023年12月6日 · The Geologic Time Scale is divided into several large units of time, including eons, eras, periods, and epochs, and it provides a framework for understanding the relationships between events in Earth’s history.
Era | Definition & Facts | Britannica
Ten eras are recognized by the International Union of Geological Sciences: the Eoarchean Era (4.0 billion to 3.6 billion years ago), the Paleoarchean Era (3.6 billion to 3.2 billion years ago), the Mesoarchean Era (3.2 billion to 2.8 billion years ago), the Neoarchean Era (2.8 billion to 2.5 billion years ago), the Paleoproterozoic Era (2.5 bill...
7.4: The Geological Time Scale - Geosciences LibreTexts
2024年4月11日 · The geological time scale is one of the crowning achievements of science, and geology in particular. It is a reference and communication system for comparing rocks and fossils from throughout the world and is geology’s equivalent of the periodic table of the elements.
Geologic Time Scale - Geological Time Line
Eons are divided into smaller time intervals known as eras. In the time scale above you can see that the Phanerozoic is divided into three eras: Cenozoic, Mesozoic and Paleozoic. Very significant events in Earth's history are used to determine the boundaries of the eras. Eras are subdivided into periods.