Useful english dictionary. 2012.
Archean Eon — or Archaean Eon or Archeozoic Eon Older of the two divisions of Precambrian time. The Archean begins with the formation of the Earth s crust с 3.8 billion years ago and extends to с 2.5 billion years ago, up to the start of the Proterozoic Eon,… … Universalium
Eón Arcaico — Saltar a navegación, búsqueda Supereón Eón M. años Fanerozoico 542,0 ±1,0 Precámbrico Proterozoico 2.500 … Wikipedia Español
Archean — [är kē′ən] adj. [< Gr archaios, ARCHAIC] [sometimes a ] designating or of the geologic eon characterized by the development of the first igneous and metamorphic rocks and the first marine microorganisms; Precambrian, esp. early Precambrian… … English World dictionary
Archean — The Archean (pronEng|ɑrˈkiːən, also spelled Archaean, formerly called the Archaeozoic (IPA|/ɑrkiəˈzoʊɪk/), also spelled Archeozoic or Archæozoic) is a geologic eon before the Proterozoic and Paleoproterozoic, before 2.5 Ga (billion years ago, or… … Wikipedia
Archean aeon — noun the time from 3,800 million years to 2,500 million years ago; earth s crust formed; unicellular organisms are earliest forms of life • Syn: ↑Archean, ↑Archean eon, ↑Archeozoic, ↑Archaeozoic, ↑Archeozoic eon, ↑Archaeozoic aeon •… … Useful english dictionary
eon — /ee euhn, ee on/, n. 1. an indefinitely long period of time; age. 2. the largest division of geologic time, comprising two or more eras. 3. Astron. one billion years. Also, aeon. [see AEON] * * * I Long span of geologic time. In formal usage,… … Universalium
Archean — or Archaean adjective Etymology: Greek archaios Date: 1872 1. of, relating to, or being the earliest eon of geological history or the corresponding system of rocks see geologic time table 2. Precambrian • Archean noun … New Collegiate Dictionary
Archeozoic eon — noun the time from 3,800 million years to 2,500 million years ago; earth s crust formed; unicellular organisms are earliest forms of life • Syn: ↑Archean, ↑Archean eon, ↑Archean aeon, ↑Archeozoic, ↑Archaeozoic, ↑Archaeozoic aeon • Derivationally… … Useful english dictionary
Precambrian eon — noun the eon following the Hadean time and preceding the Phanerozoic eon; from about 3,800 million years ago until 544 million years ago • Syn: ↑Precambrian, ↑Precambrian aeon, ↑Precambrian period • Instance Hypernyms: ↑eon, ↑aeon • Part Meron … Useful english dictionary
Proterozoic Eon — Younger of the two divisions of Precambrian time, from 2. 5 billion to 543 million years ago. Proterozoic rocks have been identified on all the continents and often constitute important sources of metallic ores, notably of iron, gold, copper,… … Universalium
