SNOWBALL EARTH   between ~750 and ~550 million years

Snowball Earth refers to hypotheses regarding paleoclimatic global-scale glaciation, claiming that the Earth's surface was nearly or entirely frozen at some points in its past. The occurrence of Snowball (or Slushball) Earths remains controversial . Proponents claim it best explains sedimentary deposits generally regarded as of glacial origin at tropical latitudes and other enigmatic features of the geological record. Opponents contest the implications of that geological evidence and the geophysical feasibility of an ice- or slush-covered ocean. (click to see all the article on Wikipedia) 

雪球地球 介於 ~7億5千萬到 ~5億5千萬年前




    北極海 發表在 痞客邦 留言(0) 人氣()