The Chaotian is a proposed time division of the
geologic time scale
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 geochr ...
. First proposed in 2010
as an
eon, it is named after
Chaos, the primeval void in
Greek mythology
A major branch of classical mythology, Greek mythology is the body of myths originally told by the ancient Greeks, and a genre of Ancient Greek folklore. These stories concern the origin and nature of the world, the lives and activities o ...
. This proposal defines the Chaotian eon as a
solar system
The Solar System Capitalization of the name varies. The International Astronomical Union, the authoritative body regarding astronomical nomenclature, specifies capitalizing the names of all individual astronomical objects but uses mixed "Solar ...
wide time between the initiation of planetary formation and the
hypothesised collision of the Protoplanet
Theia with the
proto-Earth.
A revised proposal in 2012
suggested the Chaotian as the first
era of the
Hadean
The Hadean ( ) is a geologic eon of Earth history preceding the Archean. On Earth, the Hadean began with the planet's formation about 4.54 billion years ago (although the start of the Hadean is defined as the age of the oldest solid materia ...
representing the time between the formation of the solar system c. 4.567
Ga and the oldest preserved crustal material on Earth, a c. 4.404 Ga
detrital zircon from the
Jack Hills
The Jack Hills are a range of hills in Mid West Western Australia. They are best known as the source of the oldest material of terrestrial origin found to date: Hadean zircons that formed around 4.39 billion years ago. These zircons have enable ...
of the
Narryer Terrane in
Western Australia
Western Australia (commonly abbreviated as WA) is a state of Australia occupying the western percent of the land area of Australia excluding external territories. It is bounded by the Indian Ocean to the north and west, the Southern Ocean to t ...
.
neither proposal had been adopted or officially ratified by the
International Union of Geological Sciences
The International Union of Geological Sciences (IUGS) is an international non-governmental organization devoted to international cooperation in the field of geology.
About
The IUGS was founded in 1961 and is a Scientific Union member of the Int ...
.
Subdivisions
The original proposal in 2010 divided the Chaotian into two eras and four
periods. No numerical upper age limits were provided, only the younger age limit of ~4.5 Ga for the boundary between the proposed Chaotian and Hadean boundary.
The revised proposal in 2012 did not subdivide the proposed Chaotian era (of the Hadean eon) into periods.
See also
*
Age of the Earth
The age of Earth is estimated to be 4.54 ± 0.05 billion years This age may represent the age of Earth's accretion, or core formation, or of the material from which Earth formed. This dating is based on evidence from radiometric age-dating of ...
*
Formation and evolution of the Solar System
The formation of the Solar System began about 4.6 billion years ago with the gravitational collapse of a small part of a giant molecular cloud. Most of the collapsing mass collected in the center, forming the Sun, while the rest flattened in ...
*
Geologic time scale
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 geochr ...
References
Geological eons
Geological eras
Hadean
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