Stromatolites main content.


Part of Hall of Planet Earth.

stromatolites HERO

Exhibition Text

Stromatolites — mats of bacteria that trap and precipitate sediments — were rare in the early Precambrian era, but they became more common 2.6 billion years ago, when shallow seas were more extensive. Because the atmosphere during much of the Precambrian had little oxygen, there was no protective ozone layer, and life could prosper only in water of just the right depth — shallow enough for sunlight to penetrate, but deep enough to block out the Sun’s harmful ultraviolet radiation. 

For Educators

Topic: Earth Science

Subtopic: Earth Structure

Keywords: Geology, Stratigraphic--Precambrian, Paleoclimatology, Life--Origin, Stromatolites

Audience: General