Lexic.us

Definition of Archaean

1. Adjective. Of or relating to the earliest known rocks formed during the Precambrian Eon.

Definition of Archaean

1. Adjective. (geology) of, or relating to the geologic eon from about 3,800 to 2,500 million years ago; comprises the Eoarchean, Paleoarchean, Mesoarchean and Neoarchean eras; marked by an atmosphere with little oxygen, the formation of the first continents and oceans and the emergence of simple life ¹

2. Proper noun. (geology) the Archaean eon. ¹

3. Noun. (biology) Any organism of the domain Archaea ¹

¹ Source: wiktionary.com

Definition of Archaean

1. a microorganism of the archaea [n -S]

Medical Definition of Archaean

1. The earliest period in geological period, extending up to the Lower Silurian. It includes an Azoic age, previous to the appearance of life, and an Eozoic age, including the earliest forms of life. This is equivalent to the formerly accepted term Azoic, and to the Eozoic of Dawson. Source: Websters Dictionary (01 Mar 1998)

Lexicographical Neighbors of Archaean

Literary usage of Archaean

Below you will find example usage of this term as found in modern and/or classical literature:

1. Journal by Iron and Steel Institute (1899)
"to the archaean series, or primitive rock, is thus usually covered with ... Among the archaean T^ffr occurring in Sweden, gneiss is the most common. ..."

2. The Geological Story Briefly Told by James Dwight Dana (1903)
"The archaean rocks of North America cover a large surface over the northern ... 124) the white areas are the regions of exposed archaean rocks. ..."

3. Manual of Geology: Treating of the Principles of the Science with Special by James Dwight Dana (1894)
"archaean time commences geologically with the earth as a solid globe, ... The following is a general view of the natural subdivisions of archaean time. ..."

4. Revised Text-book of Geology by James Dwight Dana, William North Rice (1897)
"archaean time, in geology, commences with the earth already a solid globe, ... Since the archaean era commenced with the origin of the earth's crust, ..."

5. The Student's Handbook of Historical Geology by Alfred John Jukes-Browne (1886)
"posed to be of archaean age occur in Normandy and Brittany, ... It is very doubtful whether the archaean rocks were originally accumulated as marine ..."

6. Science by American Association for the Advancement of Science (1883)
"A second important result is the immense simplification which is effected in archaean geology in the Canadian territory, where most questions of that ilk ..."

7. A Compend of Geology by Joseph LeConte (1888)
"Section showing Primordial unconformable on the archaean : i, archaean or Laurentian ; 2, Primordial or lowest Silurian (after Logan). distinct system and a ..."

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