Geologic time scale - Wikipedia
网页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
网页2024年9月13日 · 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. The enumeration of those geologic time units is based on stratigraphy, which is the correlation and classification of rock strata.
The Eras of the Earth With the Geologic Time Scale - ThoughtCo
网页2024年5月24日 · The Geologic Time Scale is the history of the Earth broken down into four spans of time: the Precambrian, Paleozoic, Mesozoic, and Cenozoic Eras. These eras of the Earth are marked by various events, such as the emergence of certain species, their evolution, and their extinction, that help distinguish one era from another.
History of Earth - Wikipedia
网页Earth formed around 4.54 billion years ago, approximately one-third the age of the universe, by accretion from the solar nebula. [4] [5] [6] Volcanic outgassing probably created the primordial atmosphere and then the ocean, but the early atmosphere contained almost no oxygen. Much of the Earth was molten because of frequent collisions with ...
Geological history of Earth - Wikipedia
网页Earth formed about 4.54 billion years ago by accretion from the solar nebula, a disk-shaped mass of dust and gas left over from the formation of the Sun, which also created the rest of the Solar System. Initially, Earth was molten due to extreme volcanism and frequent collisions with other bodies.
Era | Definition & Facts | Britannica
网页era, a very long span of geologic time; in formal usage, the second longest portions of geological time (eons are the longest). 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 ...
3. Geological time scale - Digital Atlas of Ancient Life
网页Earth's history is characterized by four eons; in order from oldest to youngest, these are the Hadeon, Archean, Proterozoic, and Phanerozoic. Collectively, the Hadean, Archean, and Proterozoic are sometimes informally referred to as the "Precambrian."
geologic history of Earth - Encyclopedia Britannica
网页geologic history of Earth, evolution of the continents, oceans, atmosphere, and biosphere. The layers of rock at Earth’s surface contain evidence of the evolutionary processes undergone by these components of the terrestrial environment during the times at which each layer was formed.
Geologic Time Scale - Geology (U.S. National Park Service)
网页2021年10月5日 · For the purposes of geology, the “calendar” is the geologic time scale. One way to distinguish and define each segment of time is by the occurrence of major geologic events and the appearance (and disappearance) of significant life-forms, starting with the formation of Earth’s crust followed by the appearance of ever-changing forms of ...
11.6: Geologic Time Scale - Geosciences LibreTexts
网页The Earth is very old, and the study of Earth’s past requires us to think about times that were millions or even billions of years ago. Scientists use the geologic time scale to illustrate the order in which events on Earth have happened.