THE ORIGINS OF LIFE ~3,8 billion years
Half a billion years after its formation the Earth developed a solid crust. The gigantic destructive volcanoes had calmed down, the heavy rains had stopped filling the primitive ocean that had developed. The bombardment of comets and other asteroids couldn’t trouble the sky with its primordial atmosphere any more.
The conditions on Earth now being favourable, the apparition of life had become possible.
But when, where, and how did this miracle take place?
It is difficult to answer these fundamental questions with certainty. The conveyor belt of plate tectonics (see -200,000 ; Pangaea) erased the traces of this era long passed.
The oldest traces of assumed life were found in Greenland. They are about 3.8 billion years old.
很難明確回答這些最根本的問題。板塊運動(見 紀元前二十萬年; 盤古大陸)消除了這遠古世代的痕跡。疑似最古老的痕跡在格陵蘭被發現，約莫38億年前。