Stromatolites from the Dawn of the Cambrian Explosion
Time: Vendian - Lower Cambrian Boundary (~540-520 million years old)
is 115 mm by 130 mm (maximum)
Lie de Vin Formation, Aouli Region, Morocco
Description: This stromatolite comes from the sunset of large stromatolitic
deposits. Coming from a Lowest Cambrian formation, these stromatolites
date to a time when stromatolites were no longer prevalent and abundant
on earth. The massive cyanobacterial stromatolite reefs of the Proterozoic
had yielded to new reef systems with abundant and diverse life forms.
For more than two billion years the cyanobacteria had oxygenated
earth’s atmosphere through their photosynthetic metabolism.
Earth was now hostile to them in many ways, with other heterotrophic
microbes to compete with. The associated collapse of stromatolitic
growth appears to have coincided with a transition of a shallow-water
environment to one of more open-water conditions. The stromatolite-dominated
assemblage was soon displaced by a shelly facies. At this point,
massive domal mats were replaced by smaller colonies such as Girvanella
as stromatolites attempted to retrench themselves.
Stromatolites have persisted to the modern day in such places as
Shark Bay, Australia where they continue their billions of years
old lifestyle. While this piece would make a fine present for any
natural history buff, anyone who appreciates art would also be glad
to get thus wonderful specimen as a gift.
click stromatolites pictures