Useful english dictionary. 2012.
Hadean — I noun the earliest eon in the history of the Earth from the first accretion of planetary material (around 4,600 million years ago) until the date of the oldest known rocks (about 3,800 million years ago); no evidence of life • Syn: ↑Hadean time … Useful english dictionary
Hadean aeon — noun the earliest eon in the history of the Earth from the first accretion of planetary material (around 4,600 million years ago) until the date of the oldest known rocks (about 3,800 million years ago); no evidence of life • Syn: ↑Hadean,… … Useful english dictionary
Hadean eon — noun the earliest eon in the history of the Earth from the first accretion of planetary material (around 4,600 million years ago) until the date of the oldest known rocks (about 3,800 million years ago); no evidence of life • Syn: ↑Hadean,… … Useful english dictionary
Hadean — The Hadean (pronEng|ˈheɪdiən) is the geologic eon before the Archean. It started at Earth s formation about 4.6 billion years ago (4600 Ma), and ended roughly 3.8 billion years ago, though the latter date varies according to different sources.… … Wikipedia
Hadean — /heɪˈdiən/ (say hay deeuhn), /ˈheɪdiən/ (say haydeeuhn) adjective 1. of or relating to Hades. 2. relating to the geological era stretching from the time of the earliest accretion of planetary material to form the earth and the formation of the… …
Hadean — adjective Etymology: Hades Date: 1984 of, relating to, or being the aeon of history between the formation of the solar system and the formation of the first rocks on the earth see geologic time table • Hadean noun … New Collegiate Dictionary
hadean — an eon of geologic time lasting from 4600m to 3800m years ago … Geography glossary
Geologic time scale — This clock representation shows some of the major units of geological time and definitive events of Earth history. The Hadean eon represents the time before fossil record of life on Earth; its upper boundary is now regarded as 4.0 Ga.[1] Other… … Wikipedia
Late Heavy Bombardment — The Late Heavy Bombardment (commonly referred to as the lunar cataclysm, or LHB) is a period of time approximately 3,800 to 4,100 million years ago (mya) during which a large number of impact craters are believed to have formed on the Moon, and… … Wikipedia
Precambrian — For the album by German band The Ocean, see Precambrian (album). Precambrian Period 4567.17–542 million years ago … Wikipedia
