Archean eon
- noun
- /ˈɑrkiən ˈiːɒn/
- Specialized
:
aeón Arcaico
- The Archean eon is critical to understanding the early history of our planet, as it marks the time when the Earth's crust began to solidify.
Examples
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Earth's oldest rocks, which are found in northern Canada and in the southwestern part of Greenland, date back nearly four billion years to the early Archean eon.
Academic text (2006) -
Studies by various research groups indicate that, while the carbon dioxide concentration was indeed much higher during the Archean eon, it falls well below the amount required to counter the faint Sun's effect on Earth.
Academic text (2006) -
During the Archean eon, simple unicellular organisms first appeared in Earth's oceans and began to influence the planet's atmosphere.
-
Geologists estimate that the Archean eon lasted from about 3.8 billion to 2.5 billion years ago, a time crucial for the development of life.
Synonyms
A very early time on Earth when the first rocks formed and only one-celled life existed
A very early time when Earth's first crust and simple life formed
A very early time in Earth's history when the solid crust formed and the first single-celled life appeared
A very early time about 3.8 to 2.5 billion years ago when Earth's crust and first simple life formed
Surface Forms
Morphology
This is a straightforward compositional combination: 'Archean' names a particular ancient geological interval and 'eon' denotes a very long geological time unit, so the phrase simply refers to that named eon. Although the term is technical, its meaning is directly derivable from the constituents and follows a regular naming pattern, so a learner who knows both words can understand it.
Etymology
Archean eon: The name Archean eon comes from Greek words: Archean meaning 'ancient' and eon meaning 'a very long time'. So Archean eon refers to the Earth's very early long period, when the crust formed and the first simple life appeared about 3,800 to 2,500 million years ago.
