|Hadean Time (hā-dē'ən) Pronunciation Key
The period of geologic time between 4.6 and 3.8 billion years ago, when the solar system was forming and the Earth was solidifying. No rocks are known from this time, as they were presumably eroded or drawn deep into the Earth and melted through the processes of plate tectonics. See Chart at geologic time.
|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]|